Solving input delay with pc based emulators

Tech Talk
1

http://forums.shoryuken.com/showthread.php?p=4506373#post4506373

Check out the later posts in this thread.

Any ideas?

We have found through testing that overclocking the usb ports dont help input lag. We do get true arcade input delay (1 frame) if we eliminate sound support in FBA. Any smart people out there want to take a crack at making it work WITH sound?

2

windows only? in linux one can alter the CPU scheduler and priorize usb input reading (maybe even in the source of the kernel module, but I’m not certain about this). Tell me if you want to know more about this in linux.

Also, as I said in the other thread: try lower sound freq.
Have you tried emu’s for the XBOX? maybe things are different there, since the scheduler for the CPU should be different from the one on 2000/XP/Vista

Almost forgot… disconnect your pc from the internet and shut down antivirus’s, ad-aware and everything that may use CPU, the harddrive or dvdrom drive… windows has that nice thing about drives having great percentage of cpu usage.

3

In the latest version of mame32 plus, it has 2 frames of input delay.
FBA has 1 fram of delay with sound on and 0 frames of delay with sound off.
Original Final Burn has 0 frames of input delay with sound on.

Unfortunately, it has several graphic errors and doesn’t support a lot of games. Is there anyone who would like to try other emulators and post results up here?

Basically, all you have to do is find out how to

  1. pause the game with the emulator (for ex. mame uses “p” as a pause in emulation.)

  2. find out how to step the emulation up frame by frame while it’s paused (mame uses “shift p” to advance the emulation by one frame while it’s paused.)

  3. find a game with an input test (SSF2T has an input test in the diagnostic menu)

Once you’re in the input menu, pause the emulation, hold down a button then advance the emulation by one frame. If you see the input test react, the emulator has 0 frames of delay. If it reacts on the next frame, it has 1 frame of delay, if not till the next, it has 2 frames and so on and so forth.

Any help in testing would be greatly appreciated. I’m on a mission to find the best emulator with 0 or 1 frame of delay (of course I’m more interested in 0!)

Thanks in advance!

(btw, I’m using keyboard as a my test device since I have a jpac.)

4

update: Newest version of nebula has 0 frames of delay! That includes the new CPS3 nebula emulator!

5

Nebula site’s pretty much donkey punched.

Any links?

6

Sprites are currently lagged by one frame to keep sync with backgrounds. This causes sprites to stay on screen one frame longer.
Everything else should be perfect.

7

i’d like the cps3 emu myself (nebula)

does it have full screen support?

8

It’s not nebula.

Yes, but it looks crappy, IMO.

9

ok, i’ll stick to mame then

10

I Personally don’t think it looks crappy at all AND it doesn’t have any input delay. They are arcade perfect as far as game play goes.

I think it’s just down right now. I was there earlier today and it was fine. It’ll prolly be back up soon.

there is an input lag of at least 2 frames. I’ve tested it several times.

11

I’ve only tested on UMK3, but for that the newest MAMEs have 1 frame input lag as opposed to older mames (like 0.64) which have 0 frames input lag.

Can input lag differ for each game in MAME?

12

Very interesting. Just tried with XMCOTA, VSav and MSH and got 1 frame, but 0 with UMK3 in mame32k.64. In mame90, I got 0 for all. It could differ from driver to driver, and we already know it differs from mame version to version.

13

Christ, that’s what I’ve been trying to tell people.

http://forums.shoryuken.com/showthread.php?p=4338198

Guess I shouldn’t bother arguing with people who have never played the game at the arcade in their lives to compare it.

14

Ok, it seems if you turn “direct input” off in mame, it reduces the lag, but doesn’t eliminate it in the newer versions.

Is it true that mame .90 doesn’t have input delay? I tried it and I got one frame. How did you test this?

15

LOL a people saying NEB has lag and MAME doesn’t when it is VERIFIBLY the opposite. THere is proof that NEB has none.

16

Same method you outlined above, I used the version on here http://darktemplarz.com/downloads.php, and using a PS/2 keyboard (not USB). Directinput is on and Steadykey is off, and it was done on CPS2 games + UMK3. I can’t test with my controller converter for it because I know it’s crap though, long motions (half circles, etc) aren’t even read unless done painfully slow on the PSX port.

17

It also seems possible that this 1 frame of apparent lag doesn’t actually translate to gameplay. It could just reflect a difference in when it pauses operation or it could be something like moving the input update from the end of the previous tick to the beginning of the current tick. In that case, even though when using frame advance there’s a difference, in gameplay there wouldn’t be.

18

hi what i’m on ubuntu i wouldn’t mind getting my stick to work a little better on this old laptop (p3 @ 800 mhz) so i can practice super turbo every so often

also, on usb overclocking: it doesn’t help with input delay, but it does help some with input precision.

19

Kawaks has 2 frames of lag for a few different Neo games I tested. Wouldn’t be surprised if Capcom stuff was the same.

Does the newest MAME not have a DirectInput option? I cannot find a way to disable it anywhere.

Thanks,
Josh.

20

Based on my observation on kof2000 cabs, input delay I get in kawaks offline with my stick is not that different from what I get in arcades if not better. I am talking about the time it takes for a certain charecter to respond after my input. Of course, kawaks runs on high prio by default and I did apply a couple of those USB poll rate changer programs. Or maybe its because the huge CRTs they use in arcades are slow? Anyways, I agree that the small 1 frame thing is pretty much ignorable.