# How To: Make your own diamond Thermal Paste



## UnrulyCactus

I stumbled across this today.

I have not verified that this works, but it all looks pretty legit. I'm definitely going to try this myself.

The cost seems very reasonable also.

http://inventgeek.com/Projects/Diamo.../overview.aspx

Tests are done with a Pentium D (3Ghz) overclocked to 3.4 Ghz

Quote:





> Arctic Silver with a fresh application IDLE 42c LOAD 57c





> Arctic Silver with 2 week cure IDLE 39c LOAD 54c





> Diamond Grease with a fresh application IDLE 29c LOAD 38c


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## dreadlord369

I might have believed it if it was a less of a temperature drop. I don't think any thermal paste would cause a 16 degree drop.


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## dominique120

nice +1


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## Martkilu

Quote:

total project cost: $33.00

Wonder how this stacks up to IC7? Seems like you can get 3 tubes of IC7 for that much..

Still a cool idea though


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## azminisk8r

diamonds sorta are the best conductor... but still thats a big change.
worth a shot i suppose


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## Kryten

Wow, this looks pretty fun! And the results look rewarding!


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## StretchNuts

I saw this a while back, and wanted to try it, but could never find all the ingrediants. I think that the thermal compunds out for the general public have a much lower diamond powder content, making the difference a lot smaller, and costing a lot less.


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## DuckieHo

Absolute BS. There's NO way thermal compound could cause a 16C drop. The tester is an idiot for not realizing that.


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## doat

I call bs as well if someone makes it i would happily test the hell out of it.


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## codejunki

Cool..... A 10,000$ cpu cooler ALRIGHT!!!!


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## Viscerous

Quote:


Originally Posted by *codejunki* 
Cool..... A 10,000$ cpu cooler ALRIGHT!!!!

...


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## videoman5

I always thought about doing this, and those results look really good.


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## Atomagenesis

Wow, I'm dumb. I thought this was how to make real diamonds.


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## urgrandpasdog

Hmm.... I may have to try this. I doubt there would be huge gains over something like ICD but it would be fun.


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## gerikoh

wow. a tim that is almost the same price of a dark knight.

i'm still wondering if that 16c drop is really true or not. if so, then some tim company should get into this!

interesting read though


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## Tjingsted

I call BS


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## I_dalder_I

Quote:


Originally Posted by *Atomagenesis* 
Wow, I'm dumb. I thought this was how to make real diamonds.
 








....k

Yeah this is some bull lol


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## Ladiesman101

that looks very interesting,cant wait to see results

makes me wanna grind up the earrings w diamonds from my sister XD


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## Mygaffer

Well this is interesting to say the least. I don't think we can call BS so easily, at least not without testing it yourself. I may look into to acquiring said goods, if I do I'll be sure to post me results.

If anyone else takes the time, please post results.

You'd think if this was possible the big guys would already be doing it.


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## Paradox me

Even if it doesn't work that well it sounds fun. I'll give it a try next time I can get the materials.


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## Zzyzx

Diamondium? I could gum through that with my dentures behind my back. My trademarked diamondillium is twice as hard!


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## NeoAnderson

whats the curing i read about ??
"Arctic Silver with 2 week cure"
was it sick ?


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## deltaepsylon

It's time they allowed the AS to set in, which they call 'cure' (correct me if I'm wrong)

also, do want


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## motoray

Well this could work. " Silver has a respectable thermal conductivity at: 429W/m K. Diamond on the other hand has a thermal conductivity of 900-2320 W/m K. So worst case scenario we double performance, and best case is roughly a 5x multiplier"

That's science, hard to say no to that.
I definitely want to try this. If it works my temps would be rediculous.


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## Lord Xeb

Quote:


Originally Posted by *UnrulyCactus* 
I stumbled across this today.

I have not verified that this works, but it all looks pretty legit. I'm definitely going to try this myself.

The cost seems very reasonable also.

http://inventgeek.com/Projects/Diamo.../overview.aspx

Tests are done with a Pentium D (3Ghz) overclocked to 3.4 Ghz










I think that is some BS. I am using IC7 and and I have had a drop of about 3-4C over MX-2 and when I went from AS5 to IC7 I saw a nearly a 5-7C! 16C is just crap


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## motoray

My only guess is ic7 is pretty damn cheap, they probably use not so pure diamond dust to make it as cheap as possible which would reduce performance.


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## DuckieHo

Quote:


Originally Posted by *NeoAnderson* 
whats the curing i read about ??
"Arctic Silver with 2 week cure"
was it sick ?









Wrong definition.

curing: the process of becoming hard or solid by cooling or drying or crystallization

Quote:


Originally Posted by *motoray* 
Well this could work. " Silver has a respectable thermal conductivity at: 429W/m K. Diamond on the other hand has a thermal conductivity of 900-2320 W/m K. So worst case scenario we double performance, and best case is roughly a 5x multiplier"

That's science, hard to say no to that.
I definitely want to try this. If it works my temps would be rediculous.

Ahhhh... that would be the incorrect use of science. Double thermal conductivity DOES NOT double system performance.

i.e.
Copper Thermal Conductivity: 400 W/(m K)
Aluminium Thermal Conductivity: 235 W/(m K)

A copper TRUE does not lower temperatures by 41% over an aluminum/copper TRUE. The performance gain in that case is less than 1% (considering the temperature scale starts at −273.15Â°C)


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## motoray

I would say that the design is at its limitations for what it can disipate. Changing how the way the heat gets to that item can make a big difference imo. I can acheive well under ambient liquid in my system, So the only thing keeping me from removing more heat is the compound thats transferring it to my block. So if this DIY compound can transfer the heat faster i can remove it faster. Compared to the True which has a much more limited heat dissipation would not see as great of a change.


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## supaspoon

I wouldn't be surprised to see an improvement over as5, however 16c is just crazy. Who know, maybe he had a crap mount &/or too much paste. Improper application (too much) could easily cause a difference like that.

Anyway, I'll give it a shot if i can find the materials next time i need to order supplies. Just speculating of course but I figure *at best* you might see +/- 5c improvement.


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## DuckieHo

Quote:


Originally Posted by *motoray* 
I would say that the design is at its limitations for what it can disipate. Changing how the way the heat gets to that item can make a big difference imo. I can acheive *well under ambient liqui*d in my system, So the only thing keeping me from removing more heat is the compound thats transferring it to my block. So if this DIY compound can transfer the heat faster i can remove it faster. Compared to the True which has a much more limited heat dissipation would not see as great of a change.

What do you mean by this?

Believe me, I know my basic physics... I can guarentee you that the tester was using flawed testing methodolgy.


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## ChrisB17

Ima make a diamond edition TRUE 120.


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## Adrienspawn

Quote:



Originally Posted by *ChrisB17*


Ima make a diamond edition TRUE 120.


Coming right after the TRUE Ag.

------

Yeah the tester was horrible. I'd love to see this done by a real enthusiast though, just in case it's anything better than a 3C drop.


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## 21276

im with duckie on this one, there is no way that a TIM can make that much of a difference. a few degrees here or there sure, but 16c no way.


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## lordikon

Quote:



Originally Posted by *DuckieHo*


Absolute BS. There's NO way thermal compound could cause a 16C drop. The tester is an idiot for not realizing that.


QFT. If the drop was 16C don't you guys think the thermal paste companies would be doing this and advertising the hell out of it?


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## 21276

Quote:



Originally Posted by *lordikon*


QFT. If the drop was 16C don't you guys think the thermal paste companies would be doing this and advertising the hell out of it?



/thread


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## FallenFaux

Quote:


Originally Posted by *motoray* 
I would say that the design is at its limitations for what it can disipate. Changing how the way the heat gets to that item can make a big difference imo. I can acheive well under ambient liquid in my system, So the only thing keeping me from removing more heat is the compound thats transferring it to my block. So if this DIY compound can transfer the heat faster i can remove it faster. Compared to the True which has a much more limited heat dissipation would not see as great of a change.

You can't have under ambient temperatures unless your using something other than air to cool with, it's physically impossible. BTW normal watercooling is just a more complicated air cooling, since the waters temp can't be below the air running through the rad. However, if you're using chilled air or water, that's a different story.


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## the_milk_man

Alright, I think I'm gonna test this theory out The next time I upgrade my CPU or when I get my WC gear.


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## mdogg

If anyone wants to help me pay for it, I'll do it. like $1 per person I could test it out for all o' OCN


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## ItsTopher

Quote:



Originally Posted by *mdogg*


If anyone wants to help me pay for it, I'll do it. like $1 per person I could test it out for all o' OCN



















Lmao


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## motoray

Quote:



Originally Posted by *FallenFaux*


You can't have under ambient temperatures unless your using something other than air to cool with, it's physically impossible. BTW normal watercooling is just a more complicated air cooling, since the waters temp can't be below the air running through the rad. However, if you're using chilled air or water, that's a different story.


I have a bong cooler so im under ambient 24hours a day no matter how hard i push it. its 83f in my room and my water is at 75 and i just booted 5 min ago. My water will drop another 8-10f in the next 30 min

But hey even if this paste drops only 5c under the best tim's out there 5c is still pretty big. I know 16c seams unreasonable but who knows.

Quote:



Originally Posted by *mdogg*


If anyone wants to help me pay for it, I'll do it. like $1 per person I could test it out for all o' OCN



ill send u 5$ if others chip in.


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## milkcow500

I'm even tempted to do this. I'm looking at ebay right now and I see a 50 carat 100,000 mesh diamond powder. This would probably work better?


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## motoray

Id imagine the higher carrat and finer mesh the more u can put meaning more thermal transfer.


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## supaspoon

Quote:


Originally Posted by *motoray* 
Id imagine the higher carrat and finer mesh the more u can put meaning more thermal transfer.

Well, carrat is just a measurement of quantity. But yeah I imagine the finer the powder is the more carrat you could fit in the same amount of paste.


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## DuckieHo

Quote:



Originally Posted by *supaspoon*


Well, carrat is just a measurement of quantity. But yeah I imagine the finer the powder is the more carrat you could fit in the same amount of paste.


With diamonds, *c*arat is a measurement of mass.

Diamond quality is based on color, cut, and clearity.


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## jpz

I saw this featured on hackaday a few days ago. It would be more convincing if the author had mentioned the ambient temperature during each test.

Better thermal paste decreases the temperature difference between the base of the heatsink and the surface of the CPU. The related physics:

H = kA(T2 - T1)/L

Where H is heat output in watts, k is thermal conductivity of the material, A is area in square meters of the thermal surface, T2 - T1 is the temperature difference between the sides of the conductor, and L is the length of the conductor.

Therefore you can find the temperature difference T by:

T = HL/kA

The smallest die size size of any 3ghz Pentium D(the 830, 925, and 930) is 162mm^2. I will ignore the thermal advantage the larger surface area of the IHS gives and use the die surface area instead of the surface area of the entire IHS(most of the IHS is pretty cool relative to the die area anyway). The 3ghz Pentium D's have TDP ratings of 95-130W depending on the model. I'll use 200 watts as a rough estimate(he does have his overclocked to 3.4ghz so it could be putting out more than the TDP. I have intentionally overestimated the heat output for the sake of my argument). If we assume he used a thick layer of thermal paste (1mm) and that silver based compound has a low thermal conductivity of 200 W/mk(silver is over 400, but the compound itself will be less than ideal), *the temperature difference between the heatsink and IHS with a silver based compound should be at most:

T <= (200W)(1mm)/((200 W/mk)(162mm^2) ~~ 6.2C*

The actual temperature difference is likely significantly less than this.

*Why is this important? Well, if you had a perfect TIM with infinite thermal conductivity, that temperature difference would be 0. That means the most you can gain over a silver based compound is roughly 6C.*

I would very be surprised if the actual load temperature difference between this guy's paste and AS5 was more than 2-3 degrees.


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## Kuntz

Quote:



Originally Posted by *DuckieHo*


Absolute BS. There's NO way thermal compound could cause a 16C drop. The tester is an idiot for not realizing that.


Unless the thermal compound is regenerating dry ice that uses alien technology currently unheard of on Earth.


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## DuckieHo

Quote:



Originally Posted by *jpz*


I saw this featured on hackaday a few days ago. It would be more convincing if the author had mentioned the ambient temperature during each test.

Better thermal paste decreases the temperature difference between the base of the heatsink and the surface of the CPU. The related physics:

H = kA(T2 - T1)/L

Where H is heat output in watts, k is thermal conductivity of the material, A is area in square meters of the thermal surface, T2 - T1 is the temperature difference between the sides of the conductor, and L is the length of the conductor.

Therefore you can find the temperature difference T by:

T = HL/kA

The smallest die size size of any 3ghz Pentium D(the 830, 925, and 930) is 162mm^2. I will ignore the thermal advantage the larger surface area of the IHS gives and use the die surface area instead of the surface area of the entire IHS(most of the IHS is pretty cool relative to the die area anyway). The 3ghz Pentium D's have TDP ratings of 95-130W depending on the model. I'll use 200 watts as a rough estimate(he does have his overclocked to 3.4ghz so it could be putting out more than the TDP. I have intentionally overestimated the heat output for the sake of my argument). If we assume he used a thick layer of thermal paste (1mm) and that silver based compound has a low thermal conductivity of 200 W/mk(silver is over 400, but the compound itself will be less than ideal), *the temperature difference between the heatsink and IHS with a silver based compound should be at most:

T <= (200W)(1mm)/((200 W/mk)(162mm^2) ~~ 6.2C*

The actual temperature difference is likely significantly less than this.

*Why is this important? Well, if you had a perfect TIM with infinite thermal conductivity, that temperature difference would be 0. That means the most you can gain over a silver based compound is roughly 6C.*

I would very be surprised if the actual load temperature difference between this guy's paste and AS5 was more than 2-3 degrees.


Thanks for the math.... since you mentioned real-world considerations, everyone must consider:
1) This isn't using pure silver or diamond. There's the binder grease which has a lower thermal conductivity
2) This won't fill every microscopic gap.


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## Mootsfox

Quote:



Originally Posted by *supaspoon*


I wouldn't be surprised to see an improvement over as5, however 16c is just crazy. Who know, maybe he had a crap mount &/or too much paste. Improper application (too much) could easily cause a difference like that.

Anyway, I'll give it a shot if i can find the materials next time i need to order supplies. Just speculating of course but I figure *at best* you might see +/- 5c improvement.


I can't see a date on this, but it's probably not AS5 that he is testing with. Arctic Silver has been around for awhile now and has different revisions.

40C load with an AC7 on a PD is not unheard of with AS5. My guess is that this test is just old and outdated. Mass produced pastes probably out perform this stuff, and if they don't, it's still cheaper to buy AS5 at about $1 a gram vs about $3 for this stuff.


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## /Ben

PICS! Or it didn't happen.


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## Adrienspawn

(perfect lap + cheap paste) > (no lap + good paste)


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## motoray

who cares the paste price its about the performance.


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## richardbb85

pretty cool


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## Mootsfox

Quote:



Originally Posted by *motoray*


who cares the paste price its about the performance.


I do. I see it much more as price/performance over strictly performance.


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## lordikon

Quote:


Originally Posted by *motoray* 
I have a bong cooler so im under ambient 24hours a day no matter how hard i push it. its 83f in my room and my water is at 75 and i just booted 5 min ago. My water will drop another 8-10f in the next 30 min

He said "on air". A bong cooler has liquid in it, and is an evaporative cooler.


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## 88EVGAFTW

Hell if it doesn't work, drop a line of Diamond powder on a flat surface, grab a straw, and have fun with it


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## Djghost454

Quote:


Originally Posted by *lordikon* 
He said "on air". A bong cooler has liquid in it, and is an evaporative cooler.

But still, technically cooled by air.

Unless you have phase change/slushbox/that underground copper coil I saw linked on here somewhere, you are technically cooled by air.

TEC is kind of a hybrid, the TEC cools your chip, and air cools your TEC, lol.


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## motoray

Quote:


Originally Posted by *88EVGAFTW* 
Hell if it doesn't work, drop a line of Diamond powder on a flat surface, grab a straw, and have fun with it
































If only the rush you were getting wasnt to the hospital that would be sweet.


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## jpz

@ 88EVGAFTW

Don't even suggest something like that as a joke. Diamond powder is highly abrasive- imagine millions of tiny knives made of diamond. I don't want to think what that would do to your respiratory system. Even a tiny amount in the air can be quite harmful- notice all the safety precautions the author took? You don't want to get that stuff anywhere near your face(or hands, which will transfer it to your face).


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## motoray

Quote:


Originally Posted by *jpz* 
@ 88EVGAFTW

Don't even suggest something like that as a joke. Diamond powder is highly abrasive- imagine millions of tiny knives made of diamond. I don't want to think what that would do to your respiratory system. Even a tiny amount in the air can be quite harmful- notice all the safety precautions the author took? You don't want to get that stuff anywhere near your face(or hands, which will transfer it to your face).

lol he was joking man.


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## jpz

I know he was joking. But some people might miss the joke.

While I understand that it was meant to be taken as a joke and I understand the intended humor, I do not find the joke funny at all. *"Playing" with diamond powder is not something you make jokes about.*


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## FuNkDrSpOt

Quote:



Originally Posted by *jpz*


I know he was joking. But some people might miss the joke.

While I understand that it was meant to be taken as a joke and I understand the intended humor, I do not find the joke funny at all. *"Playing" with diamond powder is not something you make jokes about.*


Who died and made you the thread nanny?

Anyone stupid enough to snort ANYTHING, let alone diamond paste deserves to die.


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## grahamcrackuh

Using this material forms an extremely well heat-conducted interface using such a high concentration of diamond, while I think 16c is ridiculous, I would expect it to perform at least 3 - 4 c better than ic7 to be honest (and therefore probably about 10 c better than as5). It's almost at the point (with such high concentration) that the heatspreader on cpu and heatsink interract almost as one substance.

@ *Duckie*, I know my physics too man, but when you consider that ic7 already does about 5c better than as5 and probably contains less than half the diamond content that DIY would, I consider it a distinct possibility that overall this stuff is performing about 10c total better than as5/


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## jpz

Quote:


Originally Posted by *FuNkDrSpOt* 
Anyone stupid enough to snort ANYTHING, let alone diamond paste deserves to die.

My cautionary message was intended for anyone who might consider handling diamond powder- _including but not limited to_ those who might try to intentionally inhale or snort it.

All the same, I think it is wrong to sit back and watch (or laugh) while someone gets hurt. Why should you or I be the one to decide who deserves to live and who deserves to die? IMHO if one has the ability to offer help to another then one should do so- if the other person deserves to die, then the other will die regardless of what one does or does not do(when the other deserves to die- not necessarily at that time).

Believe it or not, people can and ocassionally do turn their lives around. It happens far less often than not, but people when people do manage to get back on track it is an amazing thing. Out of all the people I know, these are the ones whom I respect the most- even more than the people who never strayed in the first place.

Do you not know any older people who had a less than perfect youth but are now role-model citizens whom other people look up to? Surely you do not think they deserve to die because of mistakes made in the past.


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## motoray

Welcome to the church of cooling experiments.


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## Mygaffer

Quote:


Originally Posted by *DuckieHo* 
With diamonds, *c*arat is a measurement of mass.

Diamond quality is based on color, cut, and clearity.

He said QUANTITY, not quality.


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## Mygaffer

Quote:


Originally Posted by *jpz* 
I know he was joking. But some people might miss the joke.

While I understand that it was meant to be taken as a joke and I understand the intended humor, I do not find the joke funny at all. *"Playing" with diamond powder is not something you make jokes about.*

I'm not coming down on you personally at all, but it bugs me when people say, "OMG dontz even jokes about that, the babies will do it and DIE







"

If anyone is stupid enough to snort diamond powder, esp. with all the warning stickers that usually accompany it, then that is their own fault, esp. if they get the idea from an internet forum.

Dang it Double Post. Sorry.


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## tombom

So. Anyone actually try this? I want some proof of this guys experiment.


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## Blameless

Quote:


Originally Posted by *grahamcrackuh* 
It's an extremely well conducted interface using such a high concentration of diamond, while I think 16c is ridiculous, I would expect it to perform at least 3 - 4 c better than ic7 to be honest (and therefore probably about 10 c better than as5). It's almost at the point (with such high concentration) that the heatspreader on cpu and heatsink interract almost as one substance.

IC Diamond has a higher concentration of diamond in it than this paste.

IC Diamond is *94% diamond* by weight. http://innovationcooling.com/ICDDatasheet.htm

This custom paste is *38.5% diamond* by weight. Says so right on page three.

Quote:


Originally Posted by *grahamcrackuh* 
when you consider that ic7 already does about 5c better than as5 and probably contains less than half the diamond content that DIY would, I consider it a distinct possibility that overall this stuff is performing about 10c total better than as5/

I don't believe that IC Diamond does 5C better than AS5, except in cases of extreme heat density, or _******edly incompetent_ applications of AS5. No credible review shows such a large difference, nor does the math/physics back it up.

Again this paste has less diamond per weight and volume than IC Diamond. I would be surprised if it Arctic Silver 5 did not out peform _it_ by a degree or two. If the author went from a sheet of cardboard to this paste, then I _might_ beleive a 10C+ difference in temps.

Every step of the way, the author is making nothing but error with his testing methodology. From the lack of prep documentation, to the unknown ambient temperatures, to the dubious nature of the original application of AS5, to the totaly absurd method of measuring temperatures (you _cannot_ get an accurate reading of CPU temp by pointing an IR thermometer at the heatsink), to the nonsensical means by which he loaded the CPU...

The whole article has less credibility, and far less accuracy, than the biology lab work I BSed my way through in junior high.


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## motoray

LOL ocz freeze does almost 5c better than as5. Switched mine and my brothers comp from as5 he lost 4c i lost 5c.


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## Kuntz

Quote:



Originally Posted by *motoray*


LOL ocz freeze does almost 5c better than as5. Switched mine and my brothers comp from as5 he lost 4c i lost 5c.


Cool. I have both AS5 and OCZ Freeze, and on my Phenom 9850, my friends i7, and my i7, the AS5 was always better or tied after cure-time, and by _better_ I mean, on average, 0.25 to 0.5c better. A difference hardly worth an argument. The Phenom and one i7 was lapped, along with the sink, and they were bolted on using lots of force. No paste is "5c" better than any other paste. If you take the worst paste, and the best paste, your difference will likely be under 2c. If it's not, you fail at mounting and/or have inconsistent mount pressure.

On my Phenom, I even *mixed* both AS5 and OCZ Freeze together to form a *giant smiley face* on my CPU, mounted my Zalman cooler, and received the exact same temps as a _proper_ mount. It just goes to show you how little paste matters, and how important mounting, surface, and pressure is. I will never go out of my way to buy a special paste ever again, nor will I waste my time reading any new paste reviews, because it's clear the entire paste market is based around horseshat.


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## supaspoon

Quote:



Originally Posted by *DuckieHo*


With diamonds, *c*arat is a measurement of mass.

Diamond quality is based on color, cut, and clearity.


And mass can be categorized as a measurement of *"quantity"*, which is what I said, not 'quality'.

I'm married, which dictates that I have studied the nonsensical woes of diamond marketing schemes at the command of the missus.


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## motoray

Quote:


Originally Posted by *supaspoon* 
I'm married, which dictates that I have studied the nonsensical woes of diamond marketing schemes at the command of the missus.









lol







Expert in the house!


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## cquinndesign

I saw this, its pretty interesting...


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## the_milk_man

Ok, I am seriously gonna try to make this stuff but I'm having quite a bit of trouble finding Polydimethylsiloxane and Polytetraflouroethylene.

I will be using 100k mesh diamond powder instead of the 60k mesh he used bc the 100k mesh is a lot finer and therefore I think I could get better(realistic) temps(i will use a real temp software though that is not a laser thermometer...). Hell, I'll even test this stuff on my 8800gt with a du-orb on it(and the stock cooler).


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## Shane1244

Quote:



Originally Posted by *the_milk_man*


Ok, I am seriously gonna try to make this stuff but I'm having quite a bit of trouble finding Polydimethylsiloxane and Polytetraflouroethylene.

I will be using 100k mesh diamond powder instead of the 60k mesh he used bc the 100k mesh is a lot finer and therefore I think I could get better(realistic) temps(i will use a real temp software though that is not a laser thermometer...). Hell, I'll even test this stuff on my 8800gt with a du-orb on it(and the stock cooler).


Sweet, can't wait to see what happens!


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## Pyroball

Quote:



Originally Posted by *the_milk_man*


Ok, I am seriously gonna try to make this stuff but I'm having quite a bit of trouble finding Polydimethylsiloxane and Polytetraflouroethylene.

I will be using 100k mesh diamond powder instead of the 60k mesh he used bc the 100k mesh is a lot finer and therefore I think I could get better(realistic) temps(i will use a real temp software though that is not a laser thermometer...). Hell, I'll even test this stuff on my 8800gt with a du-orb on it(and the stock cooler).


I think if you use plain old ceramique or some other silicone based paste and minimize the paste-to-diamond ratio, you should be just fine.

Also was thinking dielectric grease as a medium, but i dont know how well that would work.


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## freddyman

Quote:



Originally Posted by *the_milk_man*


Ok, I am seriously gonna try to make this stuff but I'm having quite a bit of trouble finding Polydimethylsiloxane and Polytetraflouroethylene.

I will be using 100k mesh diamond powder instead of the 60k mesh he used bc the 100k mesh is a lot finer and therefore I think I could get better(realistic) temps(i will use a real temp software though that is not a laser thermometer...). Hell, I'll even test this stuff on my 8800gt with a du-orb on it(and the stock cooler).


I'm trying this out as well. Polydimethylsiloxane = PDMS = Silicone oil. It comes in all sorts of viscosities. When it is very viscous, you can call it silicone grease (if you'd like). Polytetrafluoroethylene = PTFE. This part I don't understand. PTFE is a solid. They add it to lubricants to prevent wear. It ensures that parts won't rub together. I don't see why you would need it. After the heat sink is put in place, there is no movement and if you are trying to achieve a very high thermal conductance, you would want as much diamond as possible. If the PTFE particles are bigger than the diamond particles, then they would unnecessarily increase the minimum gap height.

I've noticed the arguing about which is the "best" thermal grease. And we have all seen the inconsistent results all over the internet. One thing you have to understand is that regardless of the bulk thermal conductivity of a grease, its overall performance is determined by the thickness of the TIM layer. The smaller the thickness, the more heat can be transferred with a smaller temperature differential. A one inch layer of diamond would probably be outperformed by a 1um layer of wood. And with the different heat sink designs and different structural make ups of the thermal greases, it is impossible to declare one to the best for all scenarios.

Here are three simple examples using AS5 and diamond paste to illustrate what I mean:

1. Heat sink with very little force keeping it on the cpu. AS5 would probably form a thick layer and not be squeezed out sufficiently. The same would go for any diamond paste especially since it is much more "viscous". Assuming we used the same thickness for both during the application, the diamond paste would outperform the AS5 because of the larger thermal conductivity.

2. Heat sink with lots of force keeping it on the cpu. AS5 would form, at the extreme, a thin layer, as small as the silver particles used. The diamond paste would form, at the extreme, a layer as thin as the diamond diameter. The commercially available diamond paste has a max particle size of 40 um. If the AS5 can form a thickness much less than 40 um, then it would obviously win. If you used diamonds of a very small size instead, it would be difficult for AS5 to win.

3. Heat sink with moderate force keeping it on the cpu. AS5 would form a layer of a smaller thickness than the diamond paste. How much smaller? Depends on the force. Who would win? Depends on the force. If the force is too large, we would default to scenario 2 where particle size matters. Otherwise the AS5 and the diamond paste would form different thicknesses based on their consistencies and the force applied. If you want to know more, go look up lubrication theory and slurry properties in a fluids textbook.

As you can see, there many ways for one grease to "out perform" another. We didn't even consider contact resistance, uneven coating, air entrapment, cure times, or heat sink/pipe performance. Essentially, the way to win this game is to use the most thermally conductive material available and form the thinnest uniform layer possible.

This is what I'm going to try to attempt. I've bought the 100 mesh diamond powder. I've also ordered some free samples of medium viscosity silicone oil. I will let you guys know how it turns out.


----------



## zorpnic

Quote: 
   Originally Posted by *Zzyzx*   Diamondium? I could gum through that with my dentures behind my back. My trademarked diamondillium is twice as hard!  
   
 YouTube - the big brain am winning again  



 

Win.


----------



## urgrandpasdog

Quote:



Originally Posted by *jpz*


My cautionary message was intended for anyone who might consider handling diamond powder- _including but not limited to_ those who might try to intentionally inhale or snort it.

All the same, I think it is wrong to sit back and watch (or laugh) while someone gets hurt. Why should you or I be the one to decide who deserves to live and who deserves to die? IMHO if one has the ability to offer help to another then one should do so- if the other person deserves to die, then the other will die regardless of what one does or does not do(when the other deserves to die- not necessarily at that time).

Believe it or not, people can and ocassionally do turn their lives around. It happens far less often than not, but people when people do manage to get back on track it is an amazing thing. Out of all the people I know, these are the ones whom I respect the most- even more than the people who never strayed in the first place.

Do you not know any older people who had a less than perfect youth but are now role-model citizens whom other people look up to? Surely you do not think they deserve to die because of mistakes made in the past.



My oh my... How on earth did we get to this, from somebody making a joke about snorting diamonds?


----------



## flak-spammer

Probably because this thread has been going a bit off topic and people were joking around because 16C drop just doesn't happen.


----------



## trueg50

Quote:


Originally Posted by *DuckieHo* 
Believe me, I know my basic physics... I can guarentee you that the tester was using flawed testing methodolgy.

I wonder if for the results he was using that hand held thermometer, and the DIY TIM wasn't doing its job well, leading to a cooler heatsink, but hot CPU.


----------



## DuckieHo

Quote:


Originally Posted by *trueg50* 
I wonder if for the results he was using that hand held thermometer, and the DIY TIM wasn't doing its job well, leading to a cooler heatsink, but hot CPU.

That would help to explain things.... furthermore, he's using an IR Thermometer which have accuracies of at 1% or worse. 1% is easily within the margin of error.

This guy doesn't know to experiment....


----------



## motoray

So milkman are you working on this or what?


----------



## freddyman

Another long winded post. I'm sorry.

So after doing some research, I can pretty safely say that the inventgeek results are BS. I'm not saying that diamond thermal grease doesn't have a valid place among the other thermal greases. There are just too many illogical steps in their process:

1. They used Polydimethylsiloxane and Polytetrafluoroethylene as there suspension fluid. Problem - Polytetrafluoroethylene is a solid. It is has no use within the thermal grease. In fact, silicone greases that come with PTFE in it have it in the form of non-uniform particles with sizes up to 1 mm. This would negate the use of micron size diamond particles.

2. They mix their diamond powder and grease by hand. Problem - that would introduce lots of air into the grease in the form of micro-macro bubbles. That would severely reduce the effectiveness of their grease. In fact, once the grease heats up, the bubbles would expand and push more of the TIM out and reduce performance even more. You would HAVE to have a degassing step in order to have a decent thermal grease.

3. Measuring the temperature of your heat sink as some sort of measure of performance. Problem - your heat sink temperature is directly related to the wattage output of your cpu and the temperature of the ambient air. It is no way related to the temperature of your cpu. This diagram will show you what I mean. Assume you have a cpu producing 60 watts of heat at thermal equilibrium:

60W -> cpu -> TIM -> Heat sink -> Air -> 60W

i.e. 60 watts in, 60 watts out. no heat stored or created or destroyed at equilibrium.

The amount of energy that the heat sink dissipates to the air is dependent on the temperature difference between the heat sink and the air and the amount of air pumped through.

60W = (some coefficient based on heat sink design) x (T_heat sink - T_air) * (volume flow-rate of air)

The 60 W is fixed by the cpu output, T_air is fixed, and the volume flow-rate of the air is fixed by the fan. That means the equilibrium temperature of your heat sink is set no matter what TIM you use.

The better the TIM, then the closer your cpu surface will reach to the heat sink temperature. If you have terrible TIM, your CPU temp will have to be really high in order to transfer that same 60 watts through your TIM.

As you can see, nobody that knows what they are doing would take temperature readings of the heat sink.

---------------------------------------------------
Having said all that, there is no reason why you can't use a diamond suspension to cool your cpu. Here is what you need:

1. Diamond powder of the smallest particle size you can get.
2. Pure silicone grease or any other viscous liquid with high thermal conductivity.
3. A vacuum chamber to remove any air from the mixture.

I have my 100,000 mesh diamond powder already. I bought some silicone grease from autozone today.

Now I'm in the process of constructing my own vacuum chamber. I have an empty fire extinguisher that I'm going to cut in half as my chamber. I have a food sealer vacuum pump. I just need a vacuum gauge, some tubing, and plastic plate and I will be set to go.

As soon as I get that setup, I'm going to make a few batches: a "perfect" batch, one without degassing, one without degassing and includes PTFE.

Then I'll setup a test using an electric resistance heater and a heat sink and test how the batches perform compared to AS5, ceramique, alumina, pure silicone grease, and industrial thermal grease.

And yes, I am unemployed at the moment.


----------



## freddyman

I made my first batch of diamond thermal grease. I don't have the vacuum system setup yet. So it is full of air right now. As far as the proportions of diamond to silicone oil go, I tried to mimic AS5's composition and its silver* to non-silver ratio. Their website states that AS5 is ~88% silver* by weight. That means it is ~41% silver by volume. Using the save volume fraction for diamonds in silicone oil gives you 2.48 grams of diamond for every gram of silicone oil. I mixed this ratio and I came out with a pretty thick paste. I added just a tiny bit more silicone oil (~+5%) and it flows much the same as AS5.

I didn't follow the ratios from inventgeek because they throw in 4 grams of PTFE particles for no reason. I would imagine their grease was much dryer than mine.

Looking more closely at what they did on inventgeek makes me wonder if they did this experiment as a promotion for the IC Diamond compound. First, they listed the grease ingredients in a way that makes it impossible to follow. If you go to a hobby store and ask for Polydimethylsiloxane and Polytetraflouroethylene, they will stare at you blankly and wonder if you are trying to build a bomb (as I found out). The way more common name for both of those are silicone oil and teflon. The silicone oil is actually hard to find in its pure form. Most automotive silicone greases add glass beads in order to prevent parts from touching. Second, if you managed to get micron size teflon bits and mix them in, it would only serve to reduce the effectiveness of your compound. Third, they posted unbelievable results even though they did not degas their compound. The average person, when faced with these hurdles but seeking the same results, might get frustrated and just order IC. Anyone that challenges their findings, is faced with the difficulty of not being able to reproduce their mixture to verify it.

With that, I will no longer compare what I'm doing with their results. I'm just going to go forward to see how effective the diamond paste can be.

I've gotten the rest of the supplies to build the vacuum chamber. Now it's a matter of putting it together and testing it.

My final step before testing the greases will be to build the testing rig. I am planning on having a thin metal plate box with a resistor attached on the inside. Placing a fix voltage across the resistor will produce a known heat output. I'll mount it on a motherboard just so the heat sink can mount over it. I'll also attach a thermal couple on the surface of the metal plate as close to the heat sink without touching it. I'll also have a thermal couple on the heat sink and take ambient air temperature readings before each run. The heat sink will have a sizable fan attached to it, running at a constant voltage.

My next post will hopefully be the results from my tests along with pictures. This will probably take a while so don't hold your breath. If anyone would like to give me any words of advice or concern, I'm all ears....or eyes in this case.

------------------
* Correction from AS5 website:
Arctic Silver 5 contains over 88% thermally Conductive *filler* by weight. In addition to micronized silver, *Arctic Silver 5 also contains sub-micron zinc oxide, aluminum oxide and boron nitride particles*. These thermally-enhanced ceramic particles improve the compound's performance and long-term stability.


----------



## XxJudxX

Wow freddyman is going to town on this lol

looking forward to the results


----------



## motoray

Why dont you just run prime 95 for a couple hours on each compound. Use ocz freeze for comparison so there is no set time.


----------



## freddyman

Quote:


Originally Posted by *motoray* 
Why dont you just run prime 95 for a couple hours on each compound. Use ocz freeze for comparison so there is no set time.

A few reasons why:

1. Consistency, voltage + resistor = known constant power. With a cpu, your heat output varies no matter what program you run.
2. I can mount temperature probes wherever I want. What I'm really looking for is the temperature jump from the cpu surface to the heat sink. Nothing else matters.
3. Most importantly, I don't have a spare system that I want to do this on.

At the end, I'll take the top two greases and test them out in a real system to see how they do.

Update: Vacuum system is up and running. Most of the testing rig is complete. I'm waiting on a thermocouple, and the will power to do all these tests.


----------



## Thaipo

I've attempted my own bit of (fruitless) research on the matter, and remember a suggestion along the lines of getting two different sized grits so that one fills the gaps of the other.

Although, of course, the downside being you shoot yourself in the foot a bit having to use a larger grit.

Anyways, figured it was an interesting thought. Good luck on your experiments, and it's nice to see somebody putting this through its paces. I'll be keeping up to date see your results, and if I can, manage to replicate them w/ out a vacuum chamber (thinking about using syringes to do the mixing, and a glass vial in a spinner to push all the air out. Might not be as efficient, but it could do the trick).


----------



## Pyroball

havnt bothered to subscribe to this til now, but I've been following it for a while. Freddyman's contribution has my interest!


----------



## tha d0ctor

can you use QZs instead to save cash!?!?!


----------



## Thaipo

Just got the vial of diamond powder. Looking at it I've realized that possibly due to the higher density (== carat?) it's very 'heavy' as compared to air, so there's less of a worry for dust inhalation than I had at least expected, so long as it is not thrown about and a mask is used.

*addendum... Although a new difficulty of getting the dust to mix appropriately without clumping may also prove difficult, or at least getting the mixture to an equilibrium, has also revealed itself.

I'll be utilizing syringes and glass vials for mixing and degassing (as stated previously, by putting the vials in a spinner for a few hours / days...whichever is more needed), all in a relatively sterile room (one with consistent air flow for the purpose of the laser cutter that occupies the same space).

Only aspect left now is to get the silicone oil. Considering how much powder I got, I might try a few different types and measures of viscosity.

I was curious if anyone knew of non-silicone-based oils / greases that might be possible to use?


----------



## freddyman

I am all done, finally. For those of you that just want to see random results without knowing what I did, skip to the bottom.
*
Testing rig*:

To create the heater, I soldered 7 x 1.8 Ohm resistors together in series. I then wrapped the resistors with copper braid and soldered the braid to a small steel plate. The steel plate was purposely unpolished in order to see the performance of the TIM's. A power supply of 19v was attached to the resistors providing an output of 28.6W. This may seem small to some, but the results can be scaled up easily, and this was the maximum the resistors could handle. Using a multimetter, the exact values for voltage and resistence gave an output of 29.8W.

The heatsink is an old OCZ model that has three heat pipes passing through a copper block at the cpu end. The heat pipes then pass through aluminum fins at the fan end.

I actually didn't have a motherboard that could mount my heatsink so I used a piece of wood, I hallowed out a cavity in the wood for the resistors to fit into and then mounted the steel plate on top of the wood. I then made anchors for the heatsink to attach on either side of the steel plate. The contact area between the steel plate and the heatsink is 3.5cm X 3cm.

On the steel plate off to one corner was securely attached a thermocouple which ran to a multimeter to read its output. I drilled a small hole in the copper block of the heatsink and ran another thermocouple inside. This thermocouple was connected to a dedicated display module. I used a small amount of Ceramique on the thermocouples to ensure good contact. Each thermocouple was calibrated such the results at any given temperature differed by less than 0.3F.

*Materials*:

Air - I ran the system completely dry as a control.
AS5
Ceramique
Dow Thermal Fluid - Dow Corning make their own special TIM. It is just silicone oil and zinc, but it is very viscous (90,000cs).
Pure Silicone Oil - Also from Dow Corning but has a viscosity of 10,000cs. DC is very generous with their free samples.
Silicone and Diamond Slurry - This is the DC silicone oil with 100,000 mesh diamonds add with a ratio of 1:1 oil to diamind by weight.
Dow Fluid w/ Diamonds - This is the DC thermal fluid with 100,000 mesh diamonds add with a ratio of 3:1 fluid to diamond by weight.
Inventgeek.com Remake - Lastly, I attempted to follow the procedure of the inventgeek article. I used 100,000 mesh diamonds and for the silicone grease, I used one with PTFE particles already in it: click. The diamond to everything else ratio was 5:2 by weight.
*Procedure*:

To make the DIY TIM's, I placed a small glass container onto a scale, measured out the amount of diamond and grease, and then mixed it by hand using a toothpick. There was no danger of inhalation as mentioned in the inventgeek article. The particles were sufficiently dense and clumped together that they didn't go anywhere. I then finished the mixing using a dremel and a special attachment that made it like a batter mixer.

For all of the TIM's that I made for myself (except for the inventgeek batch), I placed them inside of my vacuum chamber to remove air bubbles. (warning, I'm going to get nerdy here) I wanted to know what pressure I need to pump my chamber down to in order for a majority of the bubbles to be removed. In order to do that you need to combine the Young-Laplace equation with the Ideal Gas Law. You end up with a third order polynomial. I solved the equation with matlab for different bubble radii. As you can see below, even with absolute zero pressure, some bubbles will only double in size. Meaning that in a very viscous fluid, they will not float out that much faster.










With the vacuum chamber I created, I can get down to 26 to 26.5 in Hg vacuum. This means that for my altitude most of the bubbles greater than 10 um will join and float out. When vacuuming the TIM's I left them in the chamber for an hour to get the majority of the bubbles out. (It is really cool when you pump down the chamber and your TIM looks like it's boiling. I actually did end up boiling water using the chamber to verify that the pressure readings were correct.)

For the actual testing, I first tried out all of the different fluids on the test rig to both see how each of them would spread and to thoroughly get the surface contaminated by all of them. I wanted to make sure that the order in which I did the experiments did not effect the results. The procedure for a standard test was to clean the steel plate and the heatsink with a dry rag. Then I would clean both surfaces using rubbing alcohol and a lint free cloth. I would place a dime sized amount of the TIM in the center of the steel plate, and then press down on it with the heat sink until it could be attached to the wood. Once the heatsink was attached, the fan was turned on and allowed to run for 30 mins to cool down the entire system. The test rig was positioned in the center of an air conditioned room. The ambient air temperature was taken to be the average of the two thermal couples after the 30 min cool down. This was consistently ~71 F and was used as the starting temperature in the data. The heater was then turned on and a stopwatch was used to track the time. Measurements were taken at 1,2,3,4,5,10,15,20,25,30,and 60 mins. Each TIM was tested three times and the average of all three runs was used. The order of the testing was random with each of the three runs for a particular TIM spread out over the course of all testing.

In the preliminary testing, I experimented with spreading the TIM across the entire heatsink with a razor before attaching it. That always caused an drastic decrease in performance. For this reason, that method was not used.

*Results*:
T1 is the steel plate temperature.
T2 is the heatsink temperature.
The margin of error is +- 0.3 F.

The first figure shows the temperature difference between the heat sink and the ambient air temperature. As you can see for all the runs that even though the different TIM's caused different delays in reaching an equilibrium temperature, they all reached the same equilibrium temperature. This is expected since the amount of the heat it is outputting (31W) is the same regardless of the TIM used. The time axis is graphed in log form in order to see all the data points. The lines in between the data points are just for continuity.










Next is a figure showing the the temperature difference between the steel plate and the ambient air temperature. The worst performing TIM is obviously air. Next is the mixture mimicking the directions from inventgeek. It was the only DIY TIM that was not put in the vacuum chamber.










Lastly, we have the temperature difference between the heatsink and the steel plate. I've excluded the air run so that we can distinguish the results better. As you can see at equilibrium, AS5, Cermaique, and the Dow Corning Thermal Fluid were all very close to one another with AS5 being the best out of the group. For pure silicone oil, you can see that it is better than the inventgeek mixture. This is most likely because of the air trapped inside of the mixture. It could have also been because the mixture was so viscous that it did not thin as much as the oil. Once we add the diamonds, we improve the performance of the silicone oil but not by that much. Perhaps if I added more diamonds, the performance would increase, but the mixture was already pretty viscous and dry. When we added diamonds to the Dow Thermal Fluid, it improved its performance. It was actually the best performing out of all of them. The catch is that it did not improve it by all that much. As you can see, there isn't much room for performance anyways. The temperature difference between the heatsink and the steel plate for the best performing TIM's was in the 5-6 F range.










*Conclusion*:

The adding of diamonds did improve the performance of the of both the silicone oil and DC Thermal Fluid, but it did not improve them by that much. A few things might be effecting this. The mixtures might not be mixed well enough leaving clumps of diamonds. The problem with increased mixing is that it introduces more sub mm and um sized bubble. And since we cannot remove the smallest of these bubbles, increased mixing might lead to worse performance. Also, the amount of diamonds may have been too small. The problem with adding more is the viscosity of the slurry increases. Since slurries behave like solids and liquids, this may effect the mixtures ability to thin once the heatsink is added. Playing with juts these two variables adds two orders of magnitude to the complexity of the problem and that is why I did not explore them further. However, it is safe to conclude that you will not stumble upon the optimal mixture as inventgeek seems to suggest they did.

The best performing TIM turned out to be the DC Thermal Fluid with diamonds. It preformed slightly better than AS5. One may wonder why I didn't add diamonds to AS5. That is because I'm not made of money. It may have also decreased performance if I added too much or if the mixing added too many bubbles. But in the end, performance could not be improved by that much anyways.

If we take the temperature difference between the the plate and heatsink to be the average temperature across both interfaces, then the overall performance of the best performing TIM's are 4700-5700 Watts/F*m^2. Even if you were to drastically improve that, since the temperature of the heatsink is fixed by its own performance, you'd only be able to get 4-5 F improvement at the very extreme.

These results are for ~30 Watt output but they can easily be scaled up. For 60 watts, the temperature difference for the heatsink to ambient would roughly double, 6.5F --> 13F. The same would happen for the temperature difference between the steel plate and the heat sink 5F --> 10F. So with the same ambient temperature of 71F, doubling the heat output with take the heatsink equilibrium temperature from 83F to 94F. Reducing the area, will have a similar effect.

When you look at this as cost vs performance, the Dow Corning Thermal Fluid wins hands down. They sent me 1 kg of it for free. It works better than Ceramique and will be good enough for 99% of applications.

As you can see the diamonds did not perform any sort of miracle as reported by inventgeek, nor can it. All of the inconsistencies in their procedure and advice (don't add the diamonds to a zinc oxide grease as I did for the best results), combined with their insane results which are non reproducible makes me conclude that this was all a big joke played by them.

Lastly, here are some images of my setup and experimenting. Also, I've attached the data from all of my experiments. Thank you and good night.

Materials
Vacuum chamber
 I didn't have a picture of the fire extinguisher before I cut it. So I included an artists rendering of what it looked like before.
Test rig front Test rig side
Finally, here is the Dow Thermal Fluid with diamonds that beat AS5. I might try this later on an actually cpu and post results but I'm done for now.


----------



## Blameless

+rep

Nice experiment that proves the fairly obvious: the results of the inventgeek article are completely absurd.

The problem with TIMs, and a major reason why adding super conductive materials to them doesn't help as much as some people think it should, is that the thermal conductivity of the liquid is far more important than that of the material suspended in it.

This is also why the thicker pastes tend to do better, they use very high concentrations of extremely fine solids. Inventgeek only used something liek 30-40% diamond by weight. Professional TIMs are usually 70-95% filler, with just enough silicone or synthetic oil to displace the air between particles and hold the stuff together as a fluid.

Anyway, a kilogram of the Dow TIM for free is great. Should last you quite a while.

Quote:


Originally Posted by *Thaipo* 
I was curious if anyone knew of non-silicone-based oils / greases that might be possible to use?

Tried mineral oil?


----------



## LeeTness23

I am actually using the inventgeek thermal compound on my Intel Quad Core right now with very good results. i havenâ€™t testes the other compounds but it is worth mentioning this is the first DIY Thermal compound ever. and while the results of testing may be flawed with his methodology, he as inspired alot of people to experiment and opened this up as world to experiment in!


----------



## DuckieHo

Quote:


Originally Posted by *LeeTness23* 
I am actually using the inventgeek thermal compound on my Intel Quad Core right now with very good results. i haven't testes the other compounds but it is worth mentioning this is the first DIY Thermal compound ever. and while the results of testing may be flawed with his methodology, he as inspired alot of people to experiment and opened this up as world to experiment in!

I again highly doubt your results are correct. Freddyman systematical and reproducibly proved that the inventgeek mix sucks.

You think this was the first DIY thermal compound? People have been playing with making their own TIMs for over a decade.


----------



## LeeTness23

One thing to you all need to take into account is that article is 3 years old! Why hackaday even published something so old is besides meâ€¦ When he did it there was no and I repeat â€œNOâ€ Diamond based thermal compound to compare it to. The author was truly in uncharted territory. He exclusively compared it to arctic silver in his testing. In this new comparative test even the dow compounds are more modern than when this test was done. And Grammar and spelling aside I applaud the author for testing, experimenting and being the first to do anything real with diamond based thermal compounds in a how to article.


----------



## LeeTness23

One more thingâ€¦ your results are just as flawed as his are. I know of only one truly scientific study that used the appropriate scientific equipment to determine actual results. Overclockers.com conclusively showed the power of diamond based cooling a year before the InventGeek article. InventGeek even reference it. The article has been ironically removed but is available on the way back machine. So before you go throwing the first stoneâ€¦ remember your testing methods are equally flawed though well thought out. In the words of the original article, â€œa specially designed and built calorimeter was used. This is a precise instrument that cost about $75,000 to build.â€. Secondly I would never test with or use in construction for test equipment wood. It is a tremendous insulator and with each test you change the thermal characteristics of the material with repeated attaching and seating of your heat sink and smearing of thermal compounds absorbed by the wood. Finally you didnâ€™t even test and compare the actual test they did using arctic silver, so youâ€™re testing is far from conclusive. Unless you reproduce his exact environment you are not proving anything. Though kudos for the efforts!

Archived article referenced
http://web.archive.org/web/200802071.../articles1389/

Original article link
http://www.overclockers.com/articles1389/


----------



## freddyman

Quote:


Originally Posted by *LeeTness23* 
One more thingâ€¦ your results are just as flawed as his are. I know of only one truly scientific study that used the appropriate scientific equipment to determine actual results. Overclockers.com conclusively showed the power of diamond based cooling a year before the InventGeek article. InventGeek even reference it. The article has been ironically removed but is available on the way back machine. So before you go throwing the first stoneâ€¦ remember your testing methods are equally flawed though well thought out. In the words of the original article, â€œa specially designed and built calorimeter was used. This is a precise instrument that cost about $75,000 to build.â€. Secondly I would never test with or use in construction for test equipment wood. It is a tremendous insulator and with each test you change the thermal characteristics of the material with repeated attaching and seating of your heat sink and smearing of thermal compounds absorbed by the wood. Finally you didnâ€™t even test and compare the actual test they did using arctic silver, so youâ€™re testing is far from conclusive. Unless you reproduce his exact environment you are not proving anything. Though kudos for the efforts!

Archived article referenced
http://web.archive.org/web/200802071.../articles1389/

Original article link
http://www.overclockers.com/articles1389/

I've read that article, and it is completely valid. They are measuring the true thermal conductivity of the TIM's by fixing the gap between the heater and the heatsink. The problem is that in practice, you can't set the gap height between your cpu and your heatsink. You use the clamp provided and hope for the best. If you read one of the first posts I made in this thread, I talk about how different amounts of pressure from your heat sink will cause different results. This test used approximately the same force on all of the thermal greases. If one thinned more than the other and cooled better, then obviously you'd want to use that one as opposed to the grease that is 99% silver and doesn't flatten under your heatsink.

One last note I forgot to mention was that with the inventgeek batch I only mixed by hand just like they suggested in the article. The huge (mm size) clumps in that batch made me realize that I need to mix my own batches more thoroughly.


----------



## tipsycoma

I actually believe it. The 16 degree drop brings the CPU down to reasonable temps. If it were 30 C idle before and 16 C idle after, then I'd say it is BS. But the grease brought the load temps down from 54 to 38. Sounds believable to me.


----------



## freddyman

Quote:


Originally Posted by *tipsycoma* 
I actually believe it. The 16 degree drop brings the CPU down to reasonable temps. If it were 30 C idle before and 16 C idle after, then I'd say it is BS. But the grease brought the load temps down from 54 to 38. Sounds believable to me.

The one fact I cannot get passed is the inventgeek article suggesting that ~1/3 of the thermal grease should be Teflon (PTFE) bits.


----------



## ljason8eg

Quote:



Originally Posted by *tipsycoma*


I actually believe it. The 16 degree drop brings the CPU down to reasonable temps. If it were 30 C idle before and 16 C idle after, then I'd say it is BS. But the grease brought the load temps down from 54 to 38. Sounds believable to me.


So you think some TIM can make that big of a difference? The difference between ICD and some plain old grease wouldn't be 16C...not even close.


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## tipsycoma

You guys are making these temps out to be unbelievable. They certainly are possible.

You have to take a few things into consideration. Maybe he moved his PC into a colder room. Or maybe he didn't apply his AS5 correctly and applied his "invention" the right way. It doesn't specify these important factors. For all you know, he could be telling the truth about the temps, but be leaving some details out that could have added to the 16 C drop in temperature.


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## ljason8eg

Quote:



Originally Posted by *tipsycoma*


You guys are making these temps out to be unbelievable. They certainly are possible.

You have to take a few things into consideration. *Maybe he moved his PC into a colder room*. Or *maybe he didn't apply his AS5 correctly* and applied his "invention" the right way. *It doesn't specify these important factors*. For all you know, he could be telling the truth about the temps, but be leaving some details out that could have added to the 16 C drop in temperature.


Ok if those are true then it proves the test is flawed and it shouldn't have even been posted.


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## Thaipo

Good timing on Freddys' post, as I was about to go out and grab some silicone oil for my own mixture, but will now check up on Dow Cornings' site again. (Though note that last my attempt to get a sample, they denied due to utilizing a private email address :/)

In my opinion the 75k rig does indeed matter as it shows consistent results holding the width of the gap the TIM fills as a constant. However, Freddy has a point in saying that the paste isn't always consistent across the board. Perhaps this could be tested simply by measuring the gap with a set of calipers for each TIM.

I am curious as to the testing rig Freddy used; perhaps there could be some modifications done to decrease any variables that may not have been accounted for;
The wood indeed could have been a very large variable; depending on the pressure exerted by it per experiment could skew results.

Would an increase in temperature scale the results consistently or show a variance?

Possibly the method used for mixing could have been flawed as well; batter mixtures as used in the kitchen purposely allow air bubbles to form. Even with a vacuum chamber, as stated, the smaller bubbles perhaps could have been taken care of while mixing.
--Are there any other methods currently in the scientific community that could be utilized to create an equilibrium that would also compensate for the diamonds clumping?

Lastly, each batch was only tested for an hour(unless I fail at graph reading, apologies if this is the case ). As to my understanding, given a week or so of time an as5 mixture 'sets' and can become more thermally conductive. Maybe creating multiple rigs with consistencies between them could give different results.

Given an understanding that freddy 'isn't made of money,' perhaps somebody else could carry this torch. The work done here simply raises more questions, but answers a great deal. Great work to Freddy for proving what he set out to do; prove that there were great flaws in the inventgeek results.

Keep it up folks


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## NidStyles

The biggest issue with the diamond based TIM that I keep seeing people ignore is the medium to which it transfer's the thermal energy to itself. AS5 was specifically engineered to work with copper, and heatpipes.

Diamond paste done correctly will of course tranfer heat quickly enough, but the medium it transfer's the heat to in itself is still the limiting factor in the experiment. TIM doesn't effect cooling enough for it to be a constraint worthy of attention on modern heatsinks. Unless you build a heatsink with material's that are greater at thermal conductance than copper with heatpipe's you will never see the direct extreme benefit's from using diamond based TIM. Once you are using such a material then you will be limited by the material ISH and the silicon of the die itself.

It just seems people are looking at this problem in the wrong way for it to be of any consequence. The problem is the material of the Heatsink/metal plate, and not the TIM.


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## freddyman

Something people might be misunderstanding about my results is that even if you had a TIM with infinite thermal conductance and managed to trap no air in it while you were mounting the heatsink, you would still only lower the cpu temperature by 5-6F from the AS5 or the Dow Thermal Fluid. That is the most the laws of physics will allow with that particular heatsink. Look at the final graph. If 5-6 F is the difference between your computer working and your cpu being fried, then I would get a different computer or a better heat sink.

NidStyles, I'm not sure what you mean by AS5 being engineered for copper. It wets copper, but so does all the TIM's used. AS5 is just a bunch of metals in a polymer/unicorn tears suspension. But I agree that it is your heatsink that determines the lowest temperature you can get your cpu.

Thaipo, I knew someone would mention AS5's "settling period." The simple answer is that I didn't want to test for days on one TIM. Even if I had, the most it could have improved is 5-6F. If you really want that temperature jump to be zero, get some low melting point metal (liquid metal) or just solder your cpu to your heat sink. Again, it's all about your heatsink if you want your temperatures to drop. And yes, it does scale with an increase in heat output...until something melts.


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## BigpoppaFrary

no matter how much the diamond can transfer heat won't matter because the base of that heatsink will only absorb so much.

just like gold plated whatevers in a sound system. it's only as strong as the weakest part.


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## icd

Quote:



Originally Posted by *freddyman*


Something people might be misunderstanding about my results is that even if you had a TIM with infinite thermal conductance and managed to trap no air in it while you were mounting the heatsink, you would still only lower the cpu temperature by 5-6F from the AS5 or the Dow Thermal Fluid. That is the most the laws of physics will allow with that particular heatsink. Look at the final graph. If 5-6 F is the difference between your computer working and your cpu being fried, then I would get a different computer or a better heat sink.


freddyman,

Well done

A most excellent test and on target with the key point - you are driving towards zero with diminishing returns. There are no 10 - 20 C points to be gained other than improving application/contact/pressure methods.

OEM's have had some pretty good people on this problem in the best labs for a couple of decades now - Future improvements from my perspective will be more focused on quality and cost rather than absolute performance.

below is some IC Data I threw together along with the forum results. The ICD is compared to the forum results - The second comparison is the temp rise across the compound very similar to freddyman's set up where we show only 0.9C above the die temp. We also performed a solder test

For our tests I used a one inch copper die and a plain copper sink with a 60mm fan.

Different test set ups will get different numbers, the key point either way is there is a brick wall at the end of the road. Same problem with FHS and Water Cooling...bumping the limits.


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## jimibgood

I think the guy who tested this had inhaled the diamond dust and misread temps as his core speed.


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## NidStyles

Quote:



Originally Posted by *freddyman*


NidStyles, I'm not sure what you mean by AS5 being engineered for copper. It wets copper, but so does all the TIM's used. AS5 is just a bunch of metals in a polymer/unicorn tears suspension. But I agree that it is your heatsink that determines the lowest temperature you can get your cpu.


AS5 was designed to improve thermal conductance for copper based heatpipe designs that were just entering the market, and replacing the older aluminum fin designs. Before that the pastes being used had lower metallic content's, and much higher viscosity. Now we have hit the wall with heatsinks again, and need something new that's cost effective. Whomever comes up with the solution will probably be amazingly wealthy.


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