# USB vs PS/2 Keyboard: latency, bandwidth -> inputs per second?



## dan_k

Hello,

1.) PS/2 port, Wikipedia says, works at 10-16 kHz and I think protocol defines 11 bits per packet. That comes down to 16,000 / 11 = 1454.55 keys per second. True?

2.) USB default Windows polling rate is 125Hz, i.e. it has 8ms latency or lag between each packet. Now, even though each packet is 8 bytes long it seems USB keyboards still need to communicate only one key per packet, and that comes down to 125 keys per second. True?

While that may sound enough, it is only about 2 keys per frame @60fps animation, so if you play some fighter where you need to perform "DOWN+RIGHT+PUNCH" in a single frame this can be a problem, especially if there are two players both trying to report their combos in the same time.

USB keyboards are so much worse than PS/2?


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## ripster

Get a Razer Mechanical.

1000Hz polling rate.

Woohoo!

The gold connector makes it go faster too.


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## Arkuatic

Quote:


Originally Posted by *ripster* 
Get a Razer Mechanical.

1000Hz polling rate.

Woohoo!

*The gold connector makes it go faster too.
*









kidding?


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## ripster

jk. I was taught using the Socratic method.

Wikipedia is not the best place for researching PS/2. Try this. And don't forget the difference between packet based protocols and IRQ old fashioned 1987 era protocols like the Gameport, Serial Port, and Parallel Port.

Good times. I'll miss that good old PS/2 port too.


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## ripster

The OP posted the same thing over at Gamedev.net.

Didn't end well.

Quote:

Except that the number you have just called rubbish is from the specification, which you asked about in your original post.

I'm issuing you with a warning for intentionally being argumentative and goading other members.

Guys: In this sort of situation, just report the thread and don't get into a degenerative flameware.

Thread closed.
The key thing to remember is USB is a packet based protocol with the HID specification able to handle 10 keys per packet. The maximum keystrokes per second is 500. 500. One second. Try it, doubledogdareya.

It's good to know this stuff because if you believe the Razer Marketing department y'all should be using a Black Widow at 1000hz.


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## sefwe

Ah a typical gangbang thread. A new guy is asking for something, and the gang is telling him he doesnt need it. Backing it up with solid evidence like

Quote:

I have strong belief that if you take bunch of "pro" CS:S and Quake players, put them on a server where the ping is seemingly 100, when in reality it is 40, they will feel that they perform sub-par.

... Most of this is psychological.
This doesnt change a fact that i somehow believe that an USB keyboard could be a bottleneck here. Besides, im not quite sure what is it you expect to hear. Just get a PS/2 keyboard, its better anyway. Problem solved.

PS. A Serial Port will most likely outlive USB.







(as RS232 )


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## ripster

USB is the number one technological innovation of all time.

Is RS232 the one with lots and lots of those little pointy things? They would sometimes bend and break off. Like PS/2.


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## sefwe

This article is both outrageous and unfunny.
















I wonder why it lists USB at all, with it being a latercome competitor to FireWire and all







Difficult to count it as an innovation, other than maybe in Bill Gates' mind. Then again, with 2 videogames in the top10 of all PC _tech_ innovations in the history of mankind im not surprised.


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## ripster

Doom! Another classic from the days of RS232, Apple ADB, Parallel, Firewire, Gameports.

And PS/2.


http://www.youtube.com/watch?v=yr-lQZzevwA


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## 88EVGAFTW

Just get a good mouse that lets you adjust polling rate and a ps2 keyboard


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## EvanPitts

The PS/2 ports are long obsolete garbage, USB is superior in all respects. USB is entirely more than sufficient when it comes to keyboard and mouse activity; and is even fast enough for stuff that needs high speeds, like hard drives, network adapters, audio and video DACs, and external DVDs.

The port only exists these days because people want to keep their venerable old keyboards for new systems, especially when so many new keyboards are so bad from a user point of view.


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## sefwe

*ripster*
_classic from the days of .. Firewire_
Are you calling *Mac* users classic and outdated?







I'd definitely watch my back in dark passages after posts like that.







PS/2 users are more tolerant here(since they dont have to care about some inferior keyboard connectors like USB etc).


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## ripster

Quote:


Originally Posted by *EvanPitts* 
The PS/2 ports are long obsolete garbage, USB is superior in all respects. USB is entirely more than sufficient when it comes to keyboard and mouse activity; and is even fast enough for stuff that needs high speeds, like hard drives, network adapters, audio and video DACs, and external DVDs.

The port only exists these days because people want to keep their venerable old keyboards for new systems, especially when so many new keyboards are so bad from a user point of view.

Whew. I was beginning to believe I was the only one at OCN that knew that.


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## IntelLover

Quote:


Originally Posted by *EvanPitts* 
The PS/2 ports are long obsolete garbage, USB is superior in all respects. USB is entirely more than sufficient when it comes to keyboard and mouse activity; and is even fast enough for stuff that needs high speeds, like hard drives, network adapters, audio and video DACs, and external DVDs.

The port only exists these days because people want to keep their venerable old keyboards for new systems, especially when so many new keyboards are so bad from a user point of view.

Do some research please!


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## ripster

I thought that's what we were doing? Here's one of my sources of info. Please be specific what research you are looking at.

Anyway I think we reached consensus in this post. The OP went with USB.


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## dan_k

Quote:

The PS/2 ports are long obsolete garbage, USB is superior in all respects.
USB is just a middle part, it's a pipe connecting two ends. More importantly there is keyboard encoder on one end, and there is keyboard controller and buffer at the other end. As many know there are various limitation on keyboard end, such as scanning rate, blocking, ghosting... and also, what is not well known, different devices can utilize USB protocol in different ways, but what is not known at all are limitations on computer end, where USB packets are read by the host OS and stored in keyboard buffer. -- USB is good for that USB disk drive, and such, but for *KEYBOARD* with the default polling rate of 125Hz, then USB obviously sucks.

* Passmark keyboard test
http://www.passmark.com/products/keytest.htm

With this diagnostic software for USB I get minimum of 7-8ms delay between each key, even if I press three or four of them in the same time, for PS/2 this delay is 4-5ms, PS/2 wins there.










Would you like to perform some tests, and perhaps reconsider your misdirected statement?

Quote:

I thought that's what we were doing? Here's one of my sources of info. Please be specific what research you are looking at.

Anyway I think we reached consensus in this post. The OP went with USB.
That source confirms my fears, it says - "USB keyboard is slow".

The bottleneck of processing USB packets and placing them in keyboard buffer is something USB protocol and keyboard encoder can do nothing about, all this depends on Operating System and perhaps legacy support built in hardware, and I am yet to see some proof that polling keyboard 1000 times per second instead of 125 can actually make a difference as to how many keys per second can be stored in keyboard buffer and practically available to software application.

Without performing more tests and finding out actual real world numbers the only consensus I can reach, based on my own devices I tested, is that USB for keyboards/mouse sucks, but I would surely prefer to have more experimental information to make any such conclusion at all.


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## ripster

Are you using the same keyboard for both tests?

As I posted before every keyboard has a different scanning rate based on the engineer's firmware setting to makes sure he/she is removing switch debouncing effects.

I'd use that test btw but those suckers want me to pay for it and I'm cheap (my 30 days ran out looooong ago).


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## lmnop

Manyak got 6ms on the i-Rocks KR-6230 (USB) in Passmark.


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## ripster

Most keyboards are set to that 4 to 6 ms range. It's a lost cause to try and measure all this without an oscilloscope.

I think the OP (according to his posts at the other GameDev forum) is using some old keyboard.

Quote:

My USB keyboard is indeed an odd one, it's from old iMac. But still, am I in minority or majority? -- Would you mind doing USB trace test for simultaneous multiple input on your keyboard?
And I was JOKING about the 1000hz Razer polling rate. Gold USB connectors are obviously only good for looks or gamers wouldn't like them. Jeez. Joke.


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## lmnop

MOAR GOLD


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## ripster

OCN doesn't endorse Gold USB connectors I hope.


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## Crazy9000

I don't believe anyone at OCN is under the impression the difference of speed that electricity travels through gold makes a difference. Try the headphone club though, you might find someone who swears by their $300 gold plated USB cable.


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## Maytan

Quote:


Originally Posted by *Crazy9000* 
I don't believe anyone at OCN is under the impression the difference of speed that electricity travels through gold makes a difference. Try the headphone club though, you might find someone who swears by their $300 gold plated USB cable.

Oh God not the cable debates.. nonononono. Have you ever read some of the discussions about cables on Head-Fi? It's like a Civil War.


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## sefwe

It was my impression that OCN was more about "ultimate tactile experience" and "mech superiority" rather than gold cables and vacuum tube players. Also it appears it has a random guest from geekhack now, obsessed with USB and Id's videogames. (Im not saying troll because im polite.) Though claiming that Doom 1 is one of the greatest achievements of semiconductor industry really says it all.


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## sefwe

Quote:


Originally Posted by *dan_k* 

* Passmark keyboard test
http://www.passmark.com/products/keytest.htm

USB:
Depress time: 355ms
Lag time: 7ms
Char/s: 125

With this diagnostic software for USB I get minimum of 7-8ms delay between each key, even if I press three or four of them in the same time, for PS/2 this delay is 4-5ms, PS/2 wins there.


This is what i got with my Logitech Access Deluxe PS/2

PS/2
Depress time: 169ms
Lag time: 3ms
Char/s: 272

Looks pretty solid, but im unsure of how relevant this is, other than that Logitech makes good hardware, but thats hardly news. But at least we have some hard facts here, hehe.


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## Ecchi-BANZAII!!!

Quote:


Originally Posted by *lmnop* 
MOAR GOLD










Damn she was fast, but that's because she's all gold and blond.


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## darkcommon

From my POV. PS/2 is faster than USB.


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## Ecchi-BANZAII!!!

Quote:


Originally Posted by *darkcommon* 
From my POV. PS/2 is faster than USB.

It is faster when it comes to queue but not in transfer (MHz) speed.
The USB interface is like a hub, one signal at a time.
The PS/2 is always active while USB is inactive until it gets a queue.


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## De-Zant

I don't understand why people prefer USB over PS/2 for ANYTHING else than hotswapping...

USB polls 1000hz... PS/2 is interrupt based, making it very much more than 1000hz....

PS/2 has NKRO. My keyboard can hit any key and have it register . I can press ALL the keys at the same time and have them register. My keyboard is PS/2....

And YOUR USB keyboard has a maximum of 6 alphanumeric keys and 4 modifiers at a time. However, it's rare for a keyboard to support this; most keyboards only support less than 3 keys at a time at certain key combinations....

The fact of the matter is: PS/2 wins for everything except hotswapping...


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## Ecchi-BANZAII!!!

^That


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## Epitope

I've never had it happen but some people have said they can't get a system to recognize a usb keyboard when they are installing an operating system onto a blank system or a similar situation where you are operating the puter at a very basic level.

I still have an old dell PS2 keyboard stuffed away in a closet just in case I need it.


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## sefwe

How about 7 simultaneous buttons, with only 3ms lag.


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## ripster

You are talking about old old BIOS implementations of Legacy USB support. Do you really think Dell and most OEMs would ship PCs without PS/2 support and not let the customer get into the BIOS? (Wait, don't answer that







).

Traditionally and with PS/2 keyboards, keystrokes generate a hardware level interrupt (on IRQ1). This puts a keystroke into the BIOS's keyboard buffer. The OS can then retrieve keystrokes from it using the BIOS interrupt handler INT16h (a software interrupt).

With legacy support enabled, BIOS will, in a sense, translate USB keyboards into PS/2 keyboards by directing keystrokes to that keyboard buffer and letting software access it through INT16h like it would with a PS/2 board. With it disabled, the OS is left to use it's own code for everything and just gets the data over USB like with any other device.

The OCN Mechanical Keyboard Guide is working off of old news. Old assumptions.

And I've heard some people like the coffee at Dennys.


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## De-Zant

Quote:


Originally Posted by *sefwe* 
How about 7 simultaneous buttons, with only 3ms lag.


















How bout

10 buttons 5ms lag? All simultaneous....










Or how bout 17? Lag is still very small though....










MAN... I just LOVE my PS/2 keyboard....


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## ripster

You still use the original Intellimouse?

Wow, you ARE into vintage.


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## sefwe

OH SHI.. 17 simultaneous buttons.. Perfect for splitscreen racing or fighting games id say. PS/2 ofc.


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## De-Zant

Quote:


Originally Posted by *ripster* 
You still use the original Intellimouse?

Wow, you ARE into vintage.

If you are talking about the program, no, that is just the skin that the buttons display on. I use the steelseries 6gv2 and my razer imperator....

Quote:


Originally Posted by *sefwe* 
OH SHI.. 17 simultaneous buttons.. Perfect for splitscreen racing or fighting games id say. PS/2 ofc.

I pressed as many buttons as I could.... Pressing more of them made me press the F buttons which did some things that I didn't like. 17 was everything that my fingers could press


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## sefwe

Quote:


Originally Posted by *De-Zant* 
If you are talking about the program, no, that is just the skin that the buttons display on. I use the steelseries 6gv2 and my razer imperator....

I pressed as many buttons as I could.... Pressing more of them made me press the F buttons which did some things that I didn't like. 17 was everything that my fingers could press

I think this thread is done.


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## De-Zant

Quote:


Originally Posted by *sefwe* 
I think this thread is done.









How so?


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## Ecchi-BANZAII!!!

Quote:


Originally Posted by *De-Zant* 
How so?

Because of this.

Quote:


Originally Posted by *sefwe* 
OH SHI.. 17 simultaneous buttons.. Perfect for splitscreen racing or fighting games id say. PS/2 ofc.


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## De-Zant

Quote:


Originally Posted by *Ecchi-BANZAII!!!* 
Because of this.

Oh OK..

But I don't remember how many keys the finnish layout has, but I could theoretically hit up to 107 or something like that keys at a time.

Although at that point, the lag would be at least 400ms....


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## sefwe

Well its not like *ripster* will come with anything USB topping that result. But ofc the threadstarter asked for chars/s too, but 300 characters/s @3ms lag is the best i got.


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## ripster

You guys play fighting games with a keyboard?









Ahem, you're supposed to wonder what's at the end of the cord.

It's USB!


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## Ecchi-BANZAII!!!

I hoped it'd be a DB9 conector


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## ripster

Parallel Port FTW! Why.... because it's PARALLEL and has more pins for those zeros and ones to go down!


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## Blameless

My Filco is plugged into my PS/2 port.


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## Cata1yst

does it really matter?

like many have said, maybe if youre playing a fighter with a friend, and youre both 1337 with your combos.. then the NKRO advantage of Ps/2 will definately come in handy.

But online, playing some CASUAL BC2, does the fraction of a second really matter? the ping going from my computer, to my router, to my modem, to their server will kill me more likely than my usb keyboard being a fraction of a second slower. i have never gotten pissed at my keyboard for not registering a key in a game or in any other function. pissed at my network for ping spiking. yes.


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## ripster

Finally. Somebody who talks about reality, not screenshots of random keypresses with no explanation of what keyboard is being used or even defending what it all means.


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## sefwe

Lag on client side always matters. Try playing with 20fps. (Ironically thats about the framerate most online servers are running at)


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## ripster

Packet based protocols.

It's the future.

You heard it here first second.


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## Crazy9000

The polling rate difference between USB and PS/2 does not matter. The default one for USB is instant as far as anyone can be concerned.

The ONLY reason to use ps/2 is if you need the full NKRO. This would mean games that use both hands and also tons of buttons, or games where several people are using the same keyboard. I think the last time I played a game with someone on the same keyboard was in 1997.


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## sefwe

Need For Speed rox on splitscreen. Can do real-life kicking too.







Although im always loosing in racing games.

Then again im not sure what the OP is actually _asking_. The first post looks more like a statement..


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## ripster

If you want to play a coop game just buy another USB keyboard and plug it in.

They are cheap. Trust me.

If the OP would have listened to EITHER of the two threads here or at GameDev.net he would have had his OP answered. Unfortunately he has chosen not to listen to anyone here or at GameDev.net.


Quote:

USB has a fixed-length (7 Byte) data packet. The first byte contains ctrl, alt, shift etc., the remaining 6 contain key presses. There's no make/break, the host just sees when a value changes.


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## Crazy9000

Quote:


Originally Posted by *ripster* 
If you want to play a coop game just buy another USB keyboard and plug it in.

They are cheap. Trust me.

If the OP would have listened to EITHER of the two threads here or at GameDev.net he would have had his OP answered. Unfortunately he has chosen not to listen to anyone here or at GameDev.net.


Is there any real cheap ones that support a full 6 keys though? Most of the cheap ones have a standard 2kro matrix.


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## ripster

Does anybody even ship console PC ports with co-op mode any more?

If you need a keyboard with more than 6KRO get this.


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## sefwe

With multicores a PC is actually a great gaming station. Mario Cart 64 has 4ppl support, heh. Not that i played it this way on the PC, but we did play it on a N64. ))) Instead of doing math :X


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## ripster

Big hidden market for keyboard manufacturers.

4 person Mario Cart on one keyboard.


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## sefwe

Forget the past. Behold, the future of keyboards. Probably not a mech keyboard though.


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## dan_k

Ripster,

What the hell are you on about, kiddo? Listen to what?

I don't even know whether you are for USB or against it.

Quote:


Originally Posted by *Ripster*
The maximum keystrokes per second is 500. 500. One second. Try it, doubledogdareya.



a.) PS/2 ~ 1454.55 keys per second. True?

b.) USB ~ keystrokes per second is 500. True?

What in the world is your conclusion then? What are you trying to say?

You were probably thinking 500 keys per second is "good enough", right?


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## ripster

You first with your conclusion.

You started the thread.


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## sefwe

*dan_k*
I dont think he really cares, neither do i, nor should you. Just get a PS/2 keyboard and thats it. I dont get it.


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## Crazy9000

Yes 500 keys per second is enough, I don't think you would hit more even if you just randomly mashed your hands and face on the keyboard as fast as you could.


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## Cata1yst

Quote:


Originally Posted by *sefwe* 
Lag on client side always matters. Try playing with 20fps. (Ironically thats about the framerate most online servers are running at)

umm... to allude to a keyboard. thats the difference between 60.9fps and 70fps...

i really dont think that .1fps is gonna gain me any tangible advantage.


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## dan_k

Quote:


Originally Posted by *sefwe* 
Need For Speed rox on splitscreen. Can do real-life kicking too.







Although im always loosing in racing games.

Then again im not sure what the OP is actually _asking_. The first post looks more like a statement..

I'm asking for factual information, as opposed to opinions, such as those tests you did and posted results here, I thank you for that. -- What I'm really looking for is information about what happens to USB packets from the moment they are read by the OS until the time they appear in keyboard buffer and become practically available to software application.

According to source given by Ripster this is limited to 500 per second. because of PS/2 legacy support, i.e. these guys think USB packets are first converted to PS/2 and then further handled as if the packet actually came from PS/2 port, hence having all the limitations of PS/2, plus additional overhead of processing and translating USB data to PS/2. True?


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## dan_k

Quote:


Originally Posted by *sefwe* 
*dan_k*
I dont think he really cares, neither do i, nor should you. Just get a PS/2 keyboard and thats it. I dont get it.

I'm a programmer, it's my job to care about it.


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## ripster

Quote:


Originally Posted by *dan_k* 
. because of PS/2 legacy support, i.e. these guys think USB packets are first converted to PS/2 and then further handled as if the packet actually came from PS/2 port, hence having all the limitations of PS/2, plus additional overhead of processing and translating USB data to PS/2. True?


That was just Legacy BIOS support. It allows you to plug in a USB keyboard and get into the BIOS.

Have you tried contacting the USB Developers Forum? They can supply a lot of info like this HID specification.


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## Manyak

If anyone cares, I did the math for this a while ago (and it's hidden somewhere in the geekhack forums). Assuming you're using the default polling frequency:

USB has a higher bandwidth, meaning you can press more keys per second
PS/2 has a lower latency, meaning there's less of a delay between when you press the key and when it does something in your program

However, no human can reach the bandwidth of either interface. And the latency difference is small, assuming that the USB controller isn't being hogged by something else.


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## sefwe

Quote:


Originally Posted by *dan_k* 
I'm asking for factual information, as opposed to opinions, such as those tests you did and posted results here, I thank you for that. -- What I'm really looking for is information about what happens to USB packets *from the moment they are read by the OS* until the time they appear in keyboard buffer and become practically available to software application.

It is me who should thank you for providing such an interesting program and the means to test future purchases heh. (and also proving PS/2 being faster than USB)

However, while im certainly not the one to claim you dont need it because i dont need it, but this kind of information would better be searched on a OS forum, no? Worth looking on MSDN too. What do hardware guys know about specific OS and its processing. Same applies to gamdevs to some degree.


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## sefwe

heh, low keyboard latency is extremely important, its what makes people evade snipershots, and generally survive in open space, and makes all the cool tricks actually work hehe.


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## Crazy9000

Quote:


Originally Posted by *sefwe* 
heh, low keyboard latency is extremely important, its what makes people evade snipershots, and generally survive in open space, and makes all the cool tricks actually work hehe.

Sure except there's no noticeable difference between latency on ps/2 and usb, so for games it would only matter in the rare case of needing to press more then 6 keys at once.


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## ripster

All this is summarized here btw.


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## SpeedNuggeT

in terms of PS2 Vs USB, exactly the same. in terms of WHAT you can GET, USB. G15, razer mechanical etc.


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## sefwe

Quote:


Originally Posted by *Cata1yst* 
umm... to allude to a keyboard. thats the difference between 60.9fps and 70fps...

i really dont think that .1fps is gonna gain me any tangible advantage.

it not sure if a relation between a visual and a tactile lag can be easily made. But say turning Vsync on, which just adds 1 extra frame, preprocessing, makes for very noticeable tactile lag, up to unplayable in faster games like FPS or RTS


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## Manyak

Quote:


Originally Posted by *ripster* 
All this is summarized here btw.

There's some incorrect info there. You _do_ find macro programming via PS/2. Cherry does it with their POS boards.


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## sefwe

Quote:


Originally Posted by *ripster* 
All this is summarized here btw.

PS/2 Connector slowly disappearing

Stopped reading there. Its not on netbooks for space reasons thats all. As do many other ports.

gods, its says PS/2 advantage is HOTPLUGGING..







..


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## ripster

Quote:


Originally Posted by *Manyak* 
There's some incorrect info there. You _do_ find macro programming via PS/2. Cherry does it with their POS boards.

Oh yeah, forgot about that. Internal FLASH allows them to do that.

Not exactly a gaming application.


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## sefwe

Quote:


Originally Posted by *Crazy9000* 
Sure except there's no noticeable difference between latency on ps/2 and usb, so for games it would only matter in the rare case of needing to press more then 6 keys at once.

I could be wrong but didnt we just figured out that the time between 2 keypresses is 3ms on PS/2 and 7ms+ on USB? Thats 4ms difference. I cant judge the influence effectively though.

edit:
here: PS/2, 3ms delay, 300 characters/s


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## Crazy9000

So you have 4/1000th of a second difference. Even if your game is putting out 400 FPS, USB supplies 10x more speed then you need to make a movement by the next frame.


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## Manyak

Quote:


Originally Posted by *sefwe* 
I could be wrong but didnt we just figured out that the time between 2 keypresses is 3ms on PS/2 and 7ms+ on USB? Thats 4ms difference. I cant judge the influence effectively though.

edit:
here: PS/2, 3ms delay, 300 characters/s









That isn't quite accurate.

Here, I found my calculations on geekhack:

Quote:


Originally Posted by *Manyak* 
But PS/2 boards only send key information upon a change of state (once when you press the key, again when you release it), while USB boards have to send all keys with every packet. That's why PS/2 supports full NKRO and USB doesn't.

Also, those measurements you did determine the bandwidth of the connection, not the latency....

Ok check it out. Lets assume that you press a key on a PS/2 board. It has to send the following information:

1 start bit
8 data bits
1 parity bit
1 stop bit
1 ack bit
*Total: 11 bits*

PS/2 boards send 1 bit per clock high, which means that a total of 11 clock cycles are needed to transmit the data. And while some extended keys require more than a single scan code (like the Pause/Break key), even the uberl33t mama's boy doesn't care about those. So let's ignore them.

At 16.7kHz, each clock cycle is 0.058ms.
11 Clock cycles comes out to a *0.643ms* delay for a single keystroke, unless you somehow magically manage to press two keys at the exact same moment in time. In which case the second key is delayed.

This is already faster than just the USB polling rate alone, without even calculating in the protocol overhead (which is _extremely_ large once you factor in all the different layers).


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## sefwe

Quote:


Originally Posted by *Crazy9000* 
So you have 4/1000th of a second difference. Even if your game is putting out 400 FPS, USB supplies 10x more speed then you need to make a movement by the next frame.

I go sleep now its way too late over here, but these are just numbers, by that logic there shouldnt be any difference in tactile lag between 125Hz and 1000Hz mice since both fall below 60Hz of an LCD. Good night.


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## ripster

Good night. Have some nice dreams about PS/2.


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## dan_k

First of all, thank you everyone,
this is exactly what I wanted to talk about - NUMBERS.

Having actual numbers makes it possible for everyone to figure out if that is "good enough" for their particular needs, or not.

Quote:


Originally Posted by *ripster*
That was just Legacy BIOS support. It allows you to plug in a USB keyboard and get into the BIOS.

Have you tried contacting the USB Developers Forum? They can supply a lot of info like this HID specification.

PS/2 legacy support seem to be embedded in hardware and transparent to OS, so it is irrelevant whether BIOS or OS will provide the drivers to read USB port as the packets are going to be forwarded to (legacy) keyboard buffer via (legacy) keyboard controller anyway, or so it would seem. -- I did read most of those specifications, it tells me about USB keyboards and Windows drivers as much as TCP/IP specification can tell me about different network cards and practical situation with Internet lags and bandwidth problems.

I don't know about "USB Developers Forum", where is it?

Quote:


Originally Posted by *sefwe*
I could be wrong but didnt we just figured out that the time between 2 keypresses is 3ms on PS/2 and 7ms+ on USB? Thats 4ms difference. I cant judge the influence effectively though.

I am confused too. Surprisingly it seems we have indeed reached consensus, which is that PS/2 can, and more often than not, it does outperform USB keyboards, which actually comes to be quite a difference if instead of looking at "gaming keyboards" we look at "ordinary keyboards" and default polling rate of only 125Hz.

1.) Ordinary PS/2 keyboard ~ 1400 keys per second

2.) Ordinary USB keyboard ~ 125 keys per second

3.) Gaming USB keyboard ~ 500 keys per second

P.S.
That program does not always calculate "chars per second" correctly, but the "lag time" between key presses seem to be accurate number, it matches the data I get from USB trace and reflects the default polling rate of Windows, in my tests.

Quote:


Originally Posted by *Manyak*
However, no human can reach the bandwidth of either interface. And the latency difference is small, assuming that the USB controller isn't being hogged by something else.

There is more to it. This is not about rapid firing or quick tapping of buttons, this is about SIMULTANEOUS multiple input. 125 keys per second is only 2 keys per frame @60fps animation. So, imagine Street Fighter, we both push "forward+kick" in the same time, but what happens is that only you kick me and win, just becasue the two packets saying that I also did hit you never had a chance to get there in the same time/frame.

By the way I'm working on arcade emulator. The difference in milliseconds is not something you can point your finger at, or notice at all for that matter, but once you have the original game to compare it to, then it becomes rather easy to tell "something is not quite right", and sometimes you can not play the game as intended at all. Those were the games where every frame and every pixel counts. Originally arcade games polled input state via parallel lines, 8 bits at the time, instantaneously, where one bit held the information about one button state. This can be achieved with LPT (parallel) port, but technological "progress" will have us soon be completely left without that one as well. In the future, it seem convenience is more important than actual performance. Has anyone seen that movie "Idiocracy"?


----------



## ripster

Yep, like I said. Nothing beats the good old Parallel port.

But I for one don't miss those ol' IRQ collision dayz.

Good luck on the arcade emulator.


----------



## Manyak

Quote:


Originally Posted by *ripster* 
Yep, like I said. Nothing beats the good old Parallel port.

But I for one don't miss those ol' IRQ collision dayz.

Good luck on the arcade emulator.

and switching between extended and expanded memory just to get stupid programs to run, because adding 2MB of ram cost $800......


----------



## ripster

The good old days.


----------



## Maytan

I can't believe we're having an argument about USB keyboards being too slow. I bet the people who think PS/2 is noticeably faster than USB also think that IPS panels are bad for gaming because they don't have 2ms response times.


----------



## dan_k

Quote:


Originally Posted by *ripster* 
Yep, like I said. Nothing beats the good old Parallel port.

But I for one don't miss those ol' IRQ collision dayz.

Good luck on the arcade emulator.

Thank you, I'm glad we found something to agree about.

Here is the joystick that can do what arcade games originally did:
http://www2.burg-halle.de/~schwenke/parport.html










I find that on my test computers I do not need line 9 and so none of those resistors for interface to work. You also do not need diodes if you only gonna use 9 inputs (1 joystick). For each additional 9 inputs you need to add one more "ground wire" (D0-D6), so you need diodes to avoid ghosting/blocking if you are using more than one.

However, unfortunately, even though MAME, and many other emulators, support this joystick (-joy tgxlpt1) they do not utilize its capabilities fully/correctly. So, what I'm trying to do now is to remove all the input handling code from MAME and insert this driver to handle the input and directly forward it to the emulated game port, bypassing 'user interface' and all the unnecessary keyboard/input stuff that is normally going on. -- If all goes well and there is noticeable difference I will let MAME developers know so they can do with it what they please. And, if it gets included in MAME, then you too will be contributor, in a way, simply becasue you took your time and helped me find the information I was looking for, regardless if we agree or disagree, that's what discussion is all about, not like the one @ gamedev.net. Hehee. I'm not so bad once you get know me. Thanks again.

P.S.
If you would like to see some really hot debate about PS/2 vs USB vs LPT, then this one I had few weeks ago is the most hilarious one, but is also informative:

http://forum.arcadecontrols.com/inde...topic=105987.0

Have fun! By the way, some of those people there make and sell keyboard encoders (KeyWIz, Ultimarc), so I do hope you will find the discussion does indeed contain quite a bit of interesting information, if that's kind of thing you're into, otherwise it's boring... except for their insults and my "Spider-Man" spoof, but then again that might only be funny to me.


----------



## Manyak

Quote:


Originally Posted by *Maytan* 
I can't believe we're having an argument about USB keyboards being too slow. I bet the people who think PS/2 is noticeably faster than USB also think that IPS panels are bad for gaming because they don't have 2ms response times.

I _do_ think IPS panels are bad for gaming. I've got one and it sucks.....compared to the CRTs next to it







.


----------



## dan_k

Quote:


Originally Posted by *Maytan* 
I can't believe we're having an argument about USB keyboards being too slow. I bet the people who think PS/2 is noticeably faster than USB also think that IPS panels are bad for gaming because they don't have 2ms response times.

There is no argument, it's personal preference. Why did you buy your "special keyboard", why not just use the ordinary cheap one? -- So, you say 125 keys per second is "enough"? Even though I gave you example where it definitively is not enough?

Some people can play games @ 30fps, some find even 60fps is "too flickery" for them, there is no argument, if you do not care, that's fine, just go do it elsewhere. What is the point of coming into someone else's house and complain about the TV channel they are watching? Let us be, or join the discussion by actually making an argument, explain your reasoning so we know if you have understood everything correctly and are not making unreasonable assumptions, ok?


----------



## Maytan

Quote:


Originally Posted by *Manyak* 
I _do_ think IPS panels are bad for gaming. I've got one and it sucks.....compared to the CRTs next to it







.

Haha, you got me there.









Quote:


Originally Posted by *dan_k* 
There is no argument, it's personal preference. Why did you buy your "special keyboard", why not just use the ordinary cheap one? -- So, you say 125 keys per second is "enough"? Even though I gave you example where it definitively is not enough?

I bought my Das because TwoCables, lmnop, Manyak, Phaedrus, etc. convinced me that it would feel much nicer to type on than a rubber dome keyboard.

I, quite frankly, haven't seen any evidence that 125 keys isn't enough. Humans are still too slow for that to become a bottleneck. :/

FYI, I'm sharing my opinion on the discussion. It's not against the ToS or anything, you know.


----------



## Crazy9000

Quote:


Originally Posted by *dan_k* 
There is no argument, it's personal preference. Why did you buy your "special keyboard", why not just use the ordinary cheap one? -- So, you say 125 keys per second is "enough"? Even though I gave you example where it definitively is not enough?

Some people can play games @ 30fps, some find even 60fps is "too flickery" for them, there is no argument, if you do not care, that's fine, just go do it elsewhere. What is the point of coming into someone else's house and complain about the TV channel they are watching? Let us be, or join the discussion by actually making an argument, explain your reasoning so we know if you have understood everything correctly and are not making unreasonable assumptions, ok?

I can tell when a game drops down to 57fps from 60, and I haven't been able to tell any difference a/b'ing a keyboard ps/2 vs usb. Except for the 6 key limitation that is. I can hit it on the THPS games after they added the walk function, without that I can only go up to the 6 keys, which works fine on USB.


----------



## Manyak

you know, I've never actually tried to see if I could notice the difference. I've never used a USB keyboard on my desktop that I can remember. Not really because of any sort of PS/2 superiority, but because I always figured "why waste a USB port when I've got a dedicated keyboard port right there?" But that was mostly from the PIII/P4 days, when you only _had_ between 2-4 ports.


----------



## dan_k

Quote:


Originally Posted by *Crazy9000* 
I can tell when a game drops down to 57fps from 60, and I haven't been able to tell any difference a/b'ing a keyboard ps/2 vs usb. Except for the 6 key limitation that is. I can hit it on the THPS games after they added the walk function, without that I can only go up to the 6 keys, which works fine on USB.

Try tapping "jump+right" in Donkey Kong. Here, on my keyboards, it either only jumps up, or it just moves right a little a bit, rarely both. After that, assign the the same key for both "jump" and "right", then you can try again and see how it is actually supposed to jump AND move in the same time - "jump sideways". Although, this may very well be application or driver's fault.

USB could potentially outperform PS/2.

a.) Number of packets per second ~ 1000
b.) Number of bytes/keys per packet ~ 8, 10, 32 ..?

If you look at some of those custom keyboard encoders like I-PAC you may see they advertise to be able to send 32 bytes per packet, so in some theory, that USB keyboard would be able to communicate 1000x32 = 32,000 keys per second, way better than PS/2, in theory.

However, all evidence, so far, tells me that keyboard controller & keyboard buffer, to which this data is ultimately forwarded at some point, are still "legacy", and only capable of performing at PS/2 ratings, as before. So, I really doubt USB keyboards can *successfully* plug more than 1000 keys per second into keyboard buffer, regardless of their potential ability to do so, which in my opinion would only make problems like buffer overflow and such. -- Anyhow, would you mind performing some test on those keyboards of yours and share the results with us?

* USB sniffer diagnostic software, free to try:
http://www.topshareware.com/USBTrace-transfer-42419.htm

* Passmark keyboard test
http://www.passmark.com/products/keytest.htm










Here is example of using USB sniffer. It starts with four packets when I pressed [Q+W+E+R] in the same time, I hold them down for a while, and after that red line is when I release them all in the same time. You can see that even though it uses 8 bytes per packet, it still sends as many packets as keys were pressed, one-by-one, 125 keys per second max. -- Perhaps only a new/better driver could make this keyboard perform 1000 keys per second, or maybe even more, and maybe not, who knows.


----------



## dan_k

Quote:


Originally Posted by *Manyak* 
you know, I've never actually tried to see if I could notice the difference. I've never used a USB keyboard on my desktop that I can remember. Not really because of any sort of PS/2 superiority, but because I always figured "why waste a USB port when I've got a dedicated keyboard port right there?" But that was mostly from the PIII/P4 days, when you only _had_ between 2-4 ports.

Yes, things become worse if there are more than one USB device.

I'm really only talking about the numbers, I do not even expect to notice anything with 99% of the games. I just simply want to know that when I waste 5 hours trying to break a record in Donkey Kong that my game was legitimate and genuine as much as possible, so when I fail to jump over that barrel I want to blame only myself, not the keyboard, drivers, or emulator.


----------



## Crazy9000

Quote:


Originally Posted by *dan_k* 
Try tapping "jump+right" in Donkey Kong. Here, on my keyboards, it either only jumps up, or it just moves right a little a bit, rarely both. After that, assign the the same key for both "jump" and "right", then you can try again and see how it is actually supposed to jump AND move in the same time - "jump sideways". Although, this may very well be application or driver's fault.


What keyboard are you using? I just tried a flash version of donkey kong, and was able to jump any direction in the same move without any problems on my realforce via USB.


----------



## dan_k

Quote:


Originally Posted by *Crazy9000* 
What keyboard are you using? I just tried a flash version of donkey kong, and was able to jump any direction in the same move without any problems on my realforce via USB.

Any keyboard I tried give similar results, USB and PS/2 alike, laptop or desktop all the same, which is why I suspect there is lousy input implementation in MAME and why I am trying to get rid of it all, replace with direct lpt driver and hopefully see the change. -- Perhaps there is a lesson to be learned from that flash Kong, please give me a link so I can do the test on the same game and then we will be able to compare and draw some conclusions.

Do you know if your USB keyboard can send multiple keys per packet?

What minimum lag you get between key presses in "Passmark keyboard test"?


----------



## Crazy9000

I just went with the first result for "donkey kong flash" on google lol

http://www.cyberiapc.com/flashgames/donkeykong.htm

I'm at work now so I'll have to wait to do keyboard tests. If you tell me exactly what you want me to run I'll do that when I get home. I use the 55g Topre Realforce that's on elitekeyboards, I don't believe it does anything unusual with packets. It does support NKRO (if plugged into ps/2 with adapter) if that makes any difference.


----------



## dan_k

Quote:


Originally Posted by *Crazy9000* 
I just went with the first result for "donkey kong flash" on google lol

http://www.cyberiapc.com/flashgames/donkeykong.htm

That was interesting, thank you. Sometimes I could do it 7-8 times out of 10, and sometimes only 2-3 times out of ten. Then I went back to MAME, did some more testing and found out it makes quite a difference what keys are used and where are they located from each other. So, I had to think of some more precise test as having to use two hands introduced a lot of human error.

This new test requires input keys can be redefined, so we can choose two keys that are next to each other, like Q+W or DOWN+RIGHT arrows keys. Here are some new interesting discoveries:

* when I assign keys for 'right' and 'jump' to Q and W,
then I can do it 9-10 times out of 10

* when I assign keys for 'right' and 'jump' to RIGHT and DOWN arrow keys,
then I can do it only 1-2 times out of 10

Now, I can see only one explanation for this to be so, and that is because the PS/2 packets for arrow keys are actually made of two scan codes, where most of the other keys are described with only one scan code.

And, since this happens equally with USB and PS/2 keyboards of mine, then I conclude USB keyboard protocol is indeed only an outer layer around good old (legacy) keyboard buffer.

However, what is confusing about it, is that it turns out even PS/2 actually has quite a problem of delivering even only four scan codes per frame @ 60fps, while USB keyboard surprisingly can actually deliver 2 keys per frame without a problem, every time just like PS/2, even though with 125Hz polling rate it should not be able to do it so easily.









Quote:

I'm at work now so I'll have to wait to do keyboard tests. If you tell me exactly what you want me to run I'll do that when I get home. I use the 55g Topre Realforce that's on elitekeyboards, I don't believe it does anything unusual with packets. It does support NKRO (if plugged into ps/2 with adapter) if that makes any difference.
That would be most welcome.

A.) * Passmark keyboard test
http://www.passmark.com/products/keytest.htm

1. Press [Q+W+E+R] in the same time, or try banging on the keyboard as fast as you can.

2. In any case see what is the minimum number you can get for "lag time", the time between key presses.

B.) * USB sniffer diagnostic software, free to try:
http://www.topshareware.com/USBTrace-transfer-42419.htm

1. Start session

2. Press THREE buttons in the same time [Q+W+E]
...hold ~2 seconds

3. Release all three buttons in the same time
...wait ~5 seconds

4. Press FOUR buttons in the same time [Q+W+E+R]
...hold ~2 seconds

5. Release all four buttons in the same time

6. Take a screen capture you can upload here

* Maybe also apply filters, so to only show "IN" packets with "DATA".

...hopefully you will have fun doing it too


----------



## Blameless

Quote:


Originally Posted by *lmnop* 
MOAR GOLD










She could do with less gold and more ass.

Quote:


Originally Posted by *De-Zant* 
I don't understand why people prefer USB over PS/2 for ANYTHING else than hotswapping...

USB polls 1000hz... PS/2 is interrupt based, making it very much more than 1000hz....

PS/2 has NKRO. My keyboard can hit any key and have it register . I can press ALL the keys at the same time and have them register. My keyboard is PS/2....

And YOUR USB keyboard has a maximum of 6 alphanumeric keys and 4 modifiers at a time. However, it's rare for a keyboard to support this; most keyboards only support less than 3 keys at a time at certain key combinations....

The fact of the matter is: PS/2 wins for everything except hotswapping...

Yep.

Still, very few people are going to actually notice the difference in use.


----------



## Crazy9000

Alright, here you go:


----------



## dan_k

Thank you Crazy9000, that's fantastic, and much appreciated.

A.) Passmark keyboard test

*~2ms = 500 keys per second = 8 keys per frame @60fps*

This should be quite enough, even for 2-players Street Fighter game. -- I wonder if that keyboard has special drivers, or somehow keyboard encoder has convinced Windows to change default polling rate from 125Hz to 500Hz. Did you get any special drivers with it, and did you actually install them?

---------------------------------------------------------------

B.) USB sniffer test

#1 - THREE KEYS DOWN
missing two packets, skipping...

#2 - THREE KEYS UP
3.680077 - 3.653514 = 0.026563
0.026563/3 = 0.008854 *~ 9ms*

#3 - FOUR KEYS DOWN
8.965333 - 8.949534 = 0.015799
0.015799/4 = 0.003950 *~ 4ms*

#4 - FOUR KEYS UP
11.445492 - 11.429372 = 0.016120
0.016120/4 = 0.004030 *~ 4ms*

Ok, so, I have seen about dozen of these USB traces by now, yours is the first one with such strangely uneven distribution of lag between the packets. Usually packets are sent at steady rate, or fluctuate a little bit, but in your case there is some impossibly super small latency, except for the last packet where this lag is huge and interestingly evens things up at the end.

So, I took the time of the 1st packet in a batch minus last packet and then divided by the number of keys being reported to get average latency per packet. Unfortunately this data sample does not quite match with the 1st test, so I do not really know what to say, except that both programs are under slight suspicion now.

And lastly, your keyboard too uses one packet per "state change", i.e. instead of to send "4 keys are down" in one packet it sends one packet for each key, but that might be just the way it is supposed to be, I don't know that yet, though it sure is a waste.


----------



## Crazy9000

The keyboard is just using the default windows drivers.

If something was missing from that log, maybe I did something wrong, IDK. I ran the test a few times then, since I was figuring out how to apply the filter (didn't realize you had to do that first). Here's another one that's done right from the start.


----------



## dan_k

I think you are doing everything right, I often get first packets missing too, but this time you also have a packet missing in last two sets with 4 keys, so the sequence has three instead of four packets. Nevertheless I consider that data to be valid since we only really need to know the time of the 1st packet in a batch and of the last, i.e. the time taken for all the data to be sent.










# - THREE KEYS DOWN
batch of three packets missing...

# - THREE KEYS UP
3.298223 - 3.273155 = 0.025068
0.025068 / 3 = 0.008356 ~ *8ms*

# - FOUR KEYS DOWN
7.869663 -7.849103 = 0.020560
0.020560 / 4 = 0.005140 ~ *5ms*

# - FOUR KEYS UP
9.667415 - 9.641065 = 0.026350
0.026350 / 4 = 0.006586 ~ *7ms*

Similar results as the last time, bit worse maybe. The problem is that in all previous tests USB trace data matched with Passmark keyboard test, but in your case one test says 2ms, while the other shows 4ms to 8ms. I don't know which one is closer to truth, but Passmark keyboard test should be closer to measuring what I actually want to know, which is the maximum performance of keyboard buffer & keyboard controller.

I was hoping to extract that information indirectly from such data samples as USB trace, but there seem to be so many things interdependent on each other that is hard to find out what part of hardware or software is the actual bottleneck, especially since this bottleneck might not be at the same place for everyone, and this makes all the numbers slightly more meaningless.


----------



## EvanPitts

Quote:


Originally Posted by *De-Zant* 
MAN... I just LOVE my PS/2 keyboard....

Do you love your PS/2 computer though?

Thought so - long since obsolete, seeing they haven't made one in a decade and a half...


----------



## ripster

PS/2.

Retro is in. Floppies for decreased latency. The PS/2 Model 25.

The BirthPlace of the PS/2 Port


----------



## QuackPot

So do USB keyboard may any difference when they use a PS/2 adaptor?

Edit: I know this is an old thread but the post above mine are relevant and interesting to the topic at hand.


----------



## Crazy9000

Quote:


> Originally Posted by *QuackPot;14665676*
> So do USB keyboard may any difference when they use a PS/2 adaptor?
> 
> Edit: I know this is an old thread but the post above mine are relevant and interesting to the topic at hand.


If they support ps/2 adapter, its the same as having a ps/2 connector on the end.


----------



## ripster

Why would anyone use PS/2 connectors in this day and age of USB 3.0 and cheap USB hubs?

This Tardis one is quite appealing.


----------



## Riou

Quote:


> Originally Posted by *ripster;14666062*
> Why would anyone use PS/2 connectors in this day and age of USB 3.0 and cheap USB hubs?


You cannot cold boot a computer running on BIOS with a USB keyboard.


----------



## ripster

True.

That was exciting. My Corsair 600T has a power button on the top.









Hey, look at all those USB ports!


----------



## oblivionlord

"You cannot cold boot a computer running on BIOS with a USB keyboard."

I don't quite understand this scenario. Cold booting is booting from the Off position, but how does one run 'on' the bios? I'm sure you aren't referring to not being able to use a USB keyboard at post to get in the bios since it won't communicate. Mine can as well do alot of modern usb keyboards.


----------



## Crazy9000

Quote:


> Originally Posted by *oblivionlord*
> 
> "You cannot cold boot a computer running on BIOS with a USB keyboard."
> I don't quite understand this scenario. Cold booting is booting from the Off position, but how does one run 'on' the bios? I'm sure you aren't referring to not being able to use a USB keyboard at post to get in the bios since it won't communicate. Mine can as well do alot of modern usb keyboards.


Modern motherboards can use USB keyboards, it has nothing to do with your keyboard itself.


----------



## oblivionlord

The issue is not that at all. The issue is trying to figure out what this means?... "You cannot cold boot a computer running on BIOS with a USB keyboard."?


----------



## ripster

He means this:

http://geekhack.org/showwiki.php?title=USB+versus+PS+2#PowerOn+The+PC+Using+Keyboard

Somebody should really fix the OCN Mechanical Keyboard Guide.


----------



## darksen

I'm slightly ******ed, so if i'm looking for the fastest response time keyboard, I should be looking for a PS2 keyboard right?

keyboards like this that boast 1ms is a total lie? http://www.newegg.com/Product/Product.aspx?Item=N82E16823129002&Tpk=quickfire

thanks.


----------



## ripster

Depends.

When you say "slightly" is that ms or seconds?

The OCN guide is not ******ed but it sure needs an update.


----------



## darksen

ms


----------



## Crazy9000

Quote:


> Originally Posted by *darksen*
> 
> I'm slightly ******ed, so if i'm looking for the fastest response time keyboard, I should be looking for a PS2 keyboard right?
> keyboards like this that boast 1ms is a total lie? http://www.newegg.com/Product/Product.aspx?Item=N82E16823129002&Tpk=quickfire
> thanks.


Response time is the same as far as anyone can care. Any keyboard boasting about being fast is a marketing gimmick.

Only advantage to ps/2 is some keyboards only support NKRO over ps/2. Not all ps/2 boards have NKRO though.


----------



## Skylit

I don't know why, but PS/2 has this feeling where it lag spikes randomly. (At least in my experiences, more prominent on mice)

I personally consider USB superior as long as its updating at at least 1000/100 or 10ms + 6KRO (*OPINION*)


----------



## ripster

Quote:


> Originally Posted by *Skylit*
> 
> I don't know why, but PS/2 has this feeling where it lag spikes randomly. (At least in my experiences, more prominent on mice)
> 
> I personally consider USB superior as long as its updating at at least 1000/100 or 10ms + 6KRO (*OPINION*)


Agreed.

The OCN Mechanical Keyboard Guide is woefully out of date.

It's 2012 people!

_Sent From Brother Ripster's iPad_


----------



## Anhedonique

So what changed in the past 4 years or so?
What is the deciding factor that makes USB faster and more reliable as opposed to p/s2?


----------



## Crazy9000

Quote:


> Originally Posted by *Anhedonique*
> 
> So what changed in the past 4 years or so?
> What is the deciding factor that makes USB faster and more reliable as opposed to p/s2?


The only thing that's changed is now some keyboards allow 12 or more keypresses at once over USB, where the limit used to be 6. The only legitimate reason to go with PS/2 was if you had to press a bunch of keys at once for a game or something that you had to use both hands on keyboard. USB is not faster, but it's not really slower either. It is easier to deal with, so there isn't much reason to get a ps/2 keyboard over USB.


----------



## ripster

I asked this VERY question at Reddit to IT professionals.

In summary they don't really give a rat's ass what you use and USB is quite reliable these days. I keep a PS/2 keyboard around for Overclocks gone bad.

http://www.reddit.com/r/techsupport/comments/11oqwf/should_i_plug_in_my_keyboard_into_the_ps2_port_or/

In fact it was like "PS/2...Lolwut?".


----------



## Anhedonique

Thanks, having more knowledge about the topic prevents people from spreading misconceptions


----------



## ripster

Tell that to the editor of the obsolete OCN Mechanical Keyboard Guide.


----------



## chinesekiwi

Yep, the only reason to keep a PS/2 keyboard is if your USB ports are screwed (either hardware wise or software wise via dodgy BIOS) but still need to access BIOS (which did happen to me once).


----------



## ripster

YOU should edit the OCN Mechanical keyboard guide then. Really, it IS getting embarassing the amount of stuff obsolete in it.

BTW I learned that Gold IS recommended by AMP Connectors. NOT for latency though. Simply for multiple insertions and corrosion properties. Although NASTY stuff happens when paired with Tin connectors.

http://www.te.com/documentation/whitepapers/pdf/aurulrep.pdf


----------



## Anhedonique

Quote:


> Originally Posted by *ripster*
> 
> I asked this VERY question at Reddit to IT professionals.
> In summary they don't really give a rat's ass what you use and USB is quite reliable these days. I keep a PS/2 keyboard around for Overclocks gone bad.
> http://www.reddit.com/r/techsupport/comments/11oqwf/should_i_plug_in_my_keyboard_into_the_ps2_port_or/
> In fact it was like "PS/2...Lolwut?".


Actually, after reading this thread I didn't get the whole "ps2, woot?" feel out of it.


----------



## ripster

Yeah, it was more like...."just plug it in and don't bother me".

Anyway more and more gaming keyboards are mechanical AND usb only so this issue it becoming more and more moot every year.


----------



## Cartel

I just switched to PS\2 because I was sick of seeing "HID-compliant consumer control device" and having to just disable them because it will lag your game like mad.
Logitech has a real issue with it.

http://geekmontage.com/windows-8-solve-game-lagging-with-logitech-mouse-keyboard/

even on Windows 8...on a 2005 game!

So now on PS\2 I have none of that


----------



## Typhoon859

Ok, guys, I think this is the right thread for me to post this question. I'm hoping someone could really help me out here.

I'll let you guys determine what best suits my needs so I won't go into any details which I've thought out myself.

BASICALLY, I'm looking for the best choice for the lowest latency mouse which could possibly exist. High precision isn't necessary - only response time to button presses. I guess the same would go for a keyboard but more important to me is the mouse. Any recommendations? (whether it's a specific product or general idea)

Response time is all that's important.


----------

