Home Page Forums Other Emulator Message Boards Nestopia Vsync and input lag in Nestopia

What about the objective stuff? Touchy-feely stuff is only useful as a guide to finding the objective. Run audio_latency, note the value, then run time_latency and the difference is your video+input latency. What figures do you get with and without vsync? (and why the reluctance of posting your results?)

I'm attempting to improve audio_latency, since it's hard to visually tell how in-sync they are. I just tried one that had a block moving horizontally across the screen with a pointer you move left and right until it seems that the click occurs when the block crosses the pointer. I'll have to test this more tomorrow.

As you can see, I eliminated the full-screen flashing (it was too much, as you said). The only reason the original ones did that was due to them being quick hacks. I spend more time on these (should be obvious) and liked the flashing square much better. As for the sound, I figured a click would be the easiest sound to identify. I'll try other sounds too (maybe a high-pitch square wave).

Not to start an argument but there's no truly "objective" results here.It can give you a general idea and some pointers,but no hard facts. Unless someone can come up with a genius software-only test, the truly objective results can probably only be achieve via external hardware,like a high speed camera or something like you mentionned. I don't think we've reach the limits of software only test though.

Anyway, now for my results:

All test are done in fullscreen 60hz. One time with 640x480 another time with the superior resolution for Nes emulation: 512x480. (no difference noted when using 640x480 as opposed to 512x480)

In audio_latency, I adjust it to +85 to feel both audio and video are synced. This is entirely subjective though and someone else,on the same computer, might feel they are synced when the adjustment is set to say -15... And like I said, if I change the vsync setting afterward (whether it's turning it on or off) it doesn't feel quite as sync anymore.

Now for the Time_latency: I don't look at the screen and concentrate on synchronizing my presses with the beat. I get a pretty constant +140/+155. Whether Vsync is on or off it doesn't seem to have any effects on my results. And unless I got something wrong, there's no reason to expect it should,since it shouldn't have any effects on audio or input lag, only video.

You sure are good at being annoying. You can be perfectly objective here by reporting hard results. "When I ran the test, I got xx msec as a result." That's objective, regardless of whether my test ROM is working or its value is meaningful; the objective part is your report of what value it printed on screen. For that matter, "chocolate tests good to me" is also an objective report (of a subjective experience). It's really confusing, since you on the one hand talk of being objective, but then avoid mentioning objective measurements about your system, and seem in general uninterested in solving the problem you brought up. I don't get it.

Is this with vsync enabled or disabled?!?

Vsync should have no effect on this test.

Based on these values, I calculate that the latency from joypad input to video display on your system is 63 milliseconds, and the latency from joypad input to audio output is 148 milliseconds. If you run two audio_latency tests, one with vsync and one without and post the results, we can compare the input->video latencies for both, the ultimate point of the tests.

I think I figured out the reason for your contradictory approach: you're attempting to exert control on the discussion and the conclusions we might draw, perhaps thinking that we will draw the wrong ones and not solve your problem. This would explain why you are reluctant to post any hard data which we might draw our own conclusions about. Here's my advice: try a different approach of assuming that we are quite competent here and will solve the problem without the need of interference with our investigation. Sorry if I seem harsh, I just won't keep silent about bull**** (cue RB's profanity filter).

Yeah, I've gotten the impression all thread that he was fishing for some specific "fix". Emulation doesn't work that way any more, we do things *right* :-)

Your impressions. We could also say you're annoyed too easily.

Difference in perceived meaning. "Hard results" when the results is not necessarily meaningful is not true "hard results" imo

Ok ok. I don't want to argue semantics.

I gave all the information I thought was useful. Now if there something I should have mentionned,just ask and I'll asnswer...

Completely untrue.


Disabled. And then I enable it (vsync) and notice the difference... Chill, sheesh. I'm saying that +85 doesn't mean anything. It's just my impression. Someone else, with the same PC and Nestopia settings would probably give you some other numbers...


"My system"... Ok, so..what does "my system" means exactly? Is it my actual PC hardware? Or the results with Nestopia? I mean we could have different definitions of "one's system".

Because like I said, I don't experience this in MESS... So this pretty much remove the possibility that this is hardware related on my end. Unless you're going to argue that my particular hardware/software setups doesn't cope well with the way Nestopia does vsync, but I'd found that extremely suprising...I'm not the only one that noticed the lag anyway with vsync enabled in Nestopia anyway.



Most of these "numbers" don't mean anything meaningful. So any "conclusions" you could come up with don't mean anything 'either'.

Sorry, but I find these tests and conclusions similar to something like the "Torah code"...

No only the results varies for everyone,but most importantly 'the results varies every time someone perform the same test'. *You are getting random values(caused by the person and other factors..not the test itself)* in other words. Only the insane try to make sense of random values. And there's not any kind of averaging method you can use to make sense of them either. There.


Oh lord...Re-read your replies sometimes. I couldn't care less about "exercing control on the discussion". Jesus this is getting out of proportion...


I'll give you that: That's not a bad hypothesis at all. Except the problem is, I've never had a problem recognizing when the problem is on my end. I know all too well people who just argue and argue refusing to accept that the problem really is with their OS or Ram or they didn't register the program or they don't have the right drivers or they didn't power on their PC etc..

I don't mind if the problem was on my end in fact, I wouldn't mind at all because then I'd 'know' the cause.

But I know for sure your test is not going to shed light on anything. We're not going to determine just how much more lag an USB gamepad have compared to a native Nes gamepad...we're not going to determine if the lag I described with Nestopia only happens on my PC setups or everyone's...we're not gonna determine anything at the end of the day with these tests.

Personally,I would probably try to investigate the vsync code and see if there would be anything that could cause such issues or not. But I figure you're gonna think it extremely insulting and annoying that a non-programmer give his opinion on the matter

Not true R.Belmont. If if 'was' determined that this was a side effect of proper, accurate way of doing emulation then I wouldn't want to see it changed just so people find it more enjoyable.

I always prefer the accurate way rather then the easy way. Which is why I praise at every opportunity emulators like Nestopia or bsnes (edit: and MAME and MESS for that matter). So you couldn't be more wrong on this one.

I've looked through my code for possible bugs and also tried to do some things differently, but in the end, nothing came up. Redx, I've lined up a few things you may want to check/try:

- Latest video and joystick drivers installed.
- Compare joystick and keyboard response time.
- Video driver option for triple buffering is OFF.
- Video driver option for VSYNC is set to be application-controlled.
- Instead of a triple-buffering option, some video drivers may give the user an option to specify how many frames to allow it to render ahead. Change it to the lowest value.
- Simply experiment with different settings in Nestopia (resolutions, turn off sound etc), including options that "wouldn't make any sense".
- Compare with older versions of Nestopia. Most interesting would be 1.09 since that's the last version that uses DirectDraw.

using Nestopia 1.36 with my Saitek 2500 with vsync & triple buffering on, I get as low as 193 visual and similar for audio, besting around 201 (and I don't have the most lightning reflexes either, lol).

Blarrg posted 189 for an NEW on a TV, and the latest version of Nestopia I feel no noticable input lag at all, I think it's safe to say this is pretty damn clsoe to a rela NEW box, and I must say the this is best damn NES emulator I've ever used.

Thanks a lot.

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P.S. In 1.34 theres a video filter or two that doesn't show in list in 1.36 (options -> video -> filter), like 2xSaI... while I don't use them usually, sometimes I play around with that and am just curious what happened?

NEW => NES (typo)