# 1T vs 2T Command Rate - Is there a Real Performance Difference?



## SPHERE

sticky!!!

im realy interested i the answer to this aswell


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## Ket

i generally found the bandwidth difference to be around 800MB\\s+ between 1T and 2T command rates, then you have the impact on memory writes as well


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## bigvaL

well 0T is the ultimate best, but lots of ram cant handle that, 1T is better then 2T because it doesnt have to wait as long between actions, althought, some ram might not be able to run as efficiently at 1T as it can at 2T because it struggles and cant work as well. The best thing to do is aim for 0T, if its unstable, go to 1T, do a ram benchmark on sandra, set it to 2T and do it again, take whichever rate gives u the best results, thats a decent way to test, theyre pretty close but u might as well take the better one right?


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## BSman

This is going to be very interesting. Thats sounds like very extensive test, nice work. How long do you thing it will take you to finish testing?

Cheers to you dude.


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## ncsa

@Sphere, let's see of there is alot of interest before it can be a sticky maybe a FAQ. thxs

@Ket, yeah what I am finding is that the Everest and SiSoft tools are showing a gap but does this gap reflect as wide in the benchmarks, hence these test runs

@bigval, good point on the 0T I will try to include this setting across the whole range if possible (which tweak tool are you using to set 0T? A64 has only enable / disable)

@BSman, hopefully today or tomorrow pending 0T outcome...

Cheers


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## ncsa

For a much talked about subject throught out a lot of other threads there seems little interest here... is it that the facts may spoil someone's generalised statement ...









Anyway I have completed my tests and will update post #1 with the findings soon, hopefully they will be of interest.


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## The Duke

GREAT WORK ncsa!!!
Congrats on the effort


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## ncsa

Quote:


Originally Posted by *The Duke*
GREAT WORK ncsa!!!
Congrats on the effort









Thank you very much... so the next thing is the CAS ratings which Jack and I are working on together in the background and there will be another thread on that sometime next week.

Hope it all helps.


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## The Duke

Frankly... I can't wait to sell of some of my extra stuff to see how well my Ballistix actuall does on a 929 SD platform! I know Ballistix not the fastest, but it's been tested to do rather well.
On this sys I get 436Mhz @ default vdimm with 2-2-2-2-1t


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## Ket

generally no, its just synthetic marks that state a huge gap


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## Ade1965

Another good thread in the Anand Tech forums in April talked about this same issue in relation to the A64's.
http://forums.anandtech.com/messagev...VIEWTMP=Linear
Their findings suggested that in "real world" test the difference between the two settings was minor and could be overcome with the ability to up your MHz more with 2T.
This means that the A64's can be overclocked pretty well with value RAM. You will never squeeze the max out of your system but with the cheaper RAM you will have more to spend on other items, like a better graphics card.


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## ncsa

An interesting thread too, thxs. As we found the real thing to achieve with the AMD CPUs is Mhz and if possible at High FSB's giving the bandwidth. Which makes running 2T OK as you will really not notice the difference esp. if this allows you a higher stable OC .. this is got to be a good thing.


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## Ade1965

Quote:



Originally Posted by *ncsa*

this is got to be a good thing.


Agreed








I just wish I knew these findings when I built my system in December. I would have gone for cheaper RAM due to the A64's being less "picky".
On the plus side though I have been able to get my systems HTT much higher so cancelling the effects of the 2T. 
Also a separate issue with my motherboard (Asus A8N-SLI Deluxe) means that the â€œbugâ€ which prevents the HTT going over 245/250 when the command rate is set to 1T is not so important.


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## ncsa

Quote:



Originally Posted by *Ade1965*

Agreed








I just wish I knew these findings when I built my system in December. I would have gone for cheaper RAM due to the A64's being less "picky".
On the plus side though I have been able to get my systems HTT much higher so cancelling the effects of the 2T. 
Also a separate issue with my motherboard (Asus A8N-SLI Deluxe) means that the â€œbugâ€ which prevents the HTT going over 245/250 when the command rate is set to 1T is not so important.


Yes I moved off the A8N-SLi as I was unable to get the OC I was looking for but will be rebuilding this soon and it will be a nice back office workhorse but still plays games ok when needed to. There is meant to be a modded BIOS for the Asus that supports higher Vdimm (>3.0v) which would also help allow more memory options such as UTT/BH5


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## Ket

something interesting to note, everest consistently gives me scores i get with 1T and sandra reports around an 980MB\\s difference, my thoughts on this? none yet. it appears as though 1T is only really important in skt A systems

ed- ran 3dmark01SE and scores plummeted to 23.4k with the same OC settings, thats around a 3000pts drop on my normal scores. i also have some system maintinence to do so ill run the tests again, but as of this moment, the 2T results are quite self explanatory.


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## ncsa

Quote:



Originally Posted by *Ket*

something interesting to note, everest consistently gives me scores i get with 1T and sandra reports around an 980MB\\s difference, my thoughts on this? none yet. it appears as though 1T is only really important in skt A systems


One of the things that made me curious and hence running some tests was that all the various reviews around the place quote these tools and while it allows comparison between components it does not reflect the reality of the system operation.

If you compare some BW benchmarks between different CPUs say a 3500 Winnie and an FX55 with the same HW & mem modules you will find that the Winnie will show a higher BW for the same settings... this does not make any sense and which is why the BW tools must be taken with a grain of salt.

1T or 2T only has a small real difference and if you can get a higher stable OC with 2T then that will be better for any system - more Mhz's got to be a good thing.









It would be good to see if there is a real difference for the Skt A, so why not try and run some controlled tests and compare here.


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## Ket

after some maintinence on the system the results remain, 3dm01SE still reports the same, interestingly though the system test FPS are the same, but the mother nature test drops around 140FPS when at the water part.....unsure why, but its there. ill test things with doom and 3dm05 tomorrow. AM3 reports 74k vs 76.5k so not a huge difference there, super PI records a 3 second lag however, so 2T isnt what media creators want to consider using.


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## ncsa

Correct, so now for me if I can find another 7-10% increase in Mhz running 2T and is stable then it will be worth it. Afterall AMD likes Mhz and this inturn results in more FPS or crunching a file or [email protected]

If you get a series of results for the Skt-A post them up and I will link then in from the first post so it is easier for others to find.


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## Ket

i'll be able to get them soon hopefully, i'm building a pretty meaty skt A system for a mate. on running 3dm05 the result was a score of 5307, this seems low for my system but for some reason its always been kinda low on my system, last time i ran 05 with 1T timings i got a score of around 5500, the key aspect to investigate now is if switching to 2T and lowering the multiplier while upping the "FSB" results in anything posative, but at the same time for me it may not as BH-5 has always topped out @ 250.


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## blazin-asian

the max i got on my cpu/mem on 1T was 270x11, 1:1. even 271 would give me prime errors after 7 hours. i recently switched over to 2T to try 273, 1:1 and its prime stable for almost 3 hours now.

i did tests with Sisoftware Sandra and @ 270 1T was about 7500k/s and at 2T it was down to ~6700 k/s. i did tests with dividers and it was even slower then 2T. so i guess 2T is good when your mem controller sucks and u want a better OC. it might even help me get stable at 3Ghz finally. but we'll see in about 10 hours


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## ScottB

Hello

Thanks for your input.

I assumed that the "Large FFT" test in Prime was the "Test"? Have I assumed wrong?


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## PeDrO305

Im curious about the 0T setting. Howd you get that and what software/tweak did you use?


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## HighLife

i know this is a old thread. however, im having the same issue. I just got my Opty 144 and its overclocked at 300x9 (have had 2 boards, Abit N8-32x and Asus A8N-SLI Deluxe)

My problem is running 1T vs 2T, it seems that cause im running ram at DDR333 (245.5) I have to run 2T to get prime stable. However, superpi is stable with the same exact settings, just in 1T. Sandra shows me over a 1100pt difference in Memory bandwith with 1T on.

Now, they question, run at 2T (245.5) or run at 1T (200mhz).

What pisses me off to no end is this is TCCD 437...and it wont run 1T at 245 8-4-4-3...getting 2.8v

Quote:



Originally Posted by *PeDrO305*

Im curious about the 0T setting. Howd you get that and what software/tweak did you use?


I belive A64 Tweaker will let you change the cas to lower then 2.


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## Vagrant Storm

Not refering to CAS, but to Command Rate which will come as either 1T or 2T.

There has been mention of a way to get to zeroT. I, among others, would really like to be in the know on this issue...


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## sccr64472

Quote:


Originally Posted by *HighLife*
What pisses me off to no end is this is TCCD 437...and it wont run 1T at 245 8-4-4-3...getting 2.8v

Take a look at your motherboard before you blame it on your ram







What motherboard are you using?

Edit: Yep, I just read your entire post. Have you tried an MSI or DFI with that TCCD?


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## HighLife

Quote:



Originally Posted by *sccr64472*

Take a look at your motherboard before you blame it on your ram







What motherboard are you using?

Edit: Yep, I just read your entire post. Have you tried an MSI or DFI with that TCCD?


Right now im using a Asus A8N-SLI Deluxe....i have BH5 otw and DFI Nf4-D which im going to mod into a ultra.

I got my opty to 306x9 on my asus. Ram is stuck at 251 7-3-3-3 2T with 2.85 volts.

This is the only setting i can get prime stable at. Even at 200mhz ram and 5-2-2-2 1T , prime crashes in a few hours.


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## sccr64472

Quote:



Originally Posted by *HighLife*

Right now im using a Asus A8N-SLI Deluxe....i have BH5 otw and DFI Nf4-D which im going to mod into a ultra.

I got my opty to 306x9 on my asus. Ram is stuck at 251 7-3-3-3 2T with 2.85 volts.

This is the only setting i can get prime stable at. Even at 200mhz ram and 5-2-2-2 1T , prime crashes in a few hours.


I've seen many Asus A8N boards(not the A8N32) have serious problems with 1T and also with high speeds without using a divider. I don't think you'll have the same problems with the DFI.


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## markuk3

My a8n-sli deluxe is prime stable upto 330x 8 prime stable with the ram i have at 1t timmings


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## HighLife

Quote:


Originally Posted by *markuk3*
My a8n-sli deluxe is prime stable upto 330x 8 prime stable with the ram i have at 1t timmings


Must be water cooled or something....since i push air, its kinda hard to hit that HTT. Im sure extreme cooling might fix it, but since thats out of the question for me, then its to the DFI i go.

I havent seen or heard 1 person beside you getting this board stable at anything above 310.


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## ncsa

BH modules are not suitable for the Asus A8N due to the max vDimm on the MB which is not enough ...

Check out the FAQs on bohte the A8N and DFI MBs they will help you get started, if you have not already ...

Quote:


Originally Posted by *HighLife* 
Right now im using a Asus A8N-SLI Deluxe....i have BH5 otw and DFI Nf4-D which im going to mod into a ultra.

I got my opty to 306x9 on my asus. Ram is stuck at 251 7-3-3-3 2T with 2.85 volts.

This is the only setting i can get prime stable at. Even at 200mhz ram and 5-2-2-2 1T , prime crashes in a few hours.


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## N2Gaming

Good Work Subd.









N2G


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## xxicrimsonixx

Quote:


Originally Posted by *N2Gaming* 
Good Work Subd.









N2G

This tread is like 2 years old...


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## nemaca

Yeah, and we are still stuck with T1 vs T2 on ddr2, go figure, no alien tech yet


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## 88EVGAFTW

Good read, a little dated, but this should be useful for some. 1T FTW, I ran maxxmem at 2T same CAS timings and I lost about 240 points when using somewhat lose timings. However, 2T with 8-9-8-25-66 did about as good as 1T with 9-9-9-27-88


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## Capwn




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## JTD92

Wow a lot people got banned in this thread.


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