Vsync = Lag

[vrm]

Hi, I've been using winuae on and off for many years and have always had input lag (mouse) when vsync is enabled. In fact this is the one reason I have kept going back to real hardware in the past. Fullscreen without vsync is fine.

I've recently bought a new rig that I plan to put into a mame cabinet running winuae.. After installing winuae last night I've noticed the vsync lag is still there! I know there's a few threads addressing this issue but none provide some sort of solution..

I'd love to get this sorted once and for all because the lag really destroys any authentic feel to the emulation.

[vrm]

FYI this is the 3rd machine over the past 3 years I've had vsync lag with.
The only hardware that I've not upgraded over the years is the 19" Samsung CRT.. but surely this is not the problem.

My current system is:
Windows 7 x64
Intel Core 2 Duo E8400 overclocked to 3.8Ghz
4GB ram
Gigabyte HD4550
Samsung 997mb 19" CRT (using 720x576 @ 50hz via powerstrip)

I figured with such a new setup the Vsync lag in winuae would cease to exist.. unfortunately this was not the case

basis of problem:
Fullscreen + Vsync = smooth scrolling & annoying mouse/input lag, winuae CPU stays on 100%
Fullscreen + no Vsync = choppy scrolling, no lag, CPU hovers between 05 and 30..

[Toni Wilen]

Set priority to below normal. It might help.

Vsync in games also have input lag in some systems and there does not seem to be any common solution. (=this is not an application bug)

[vrm]

Changing priority didn't help unfortunately.

It would be great to know which systems in particular are affected
Every system I've put together all had completely different types of hardware, and all had the same problem. Surely I'm not that unlucky

[Leffmann]

Reduce the number of screen back-buffers. Ideally you want only 1. I've heard that WinUAE accepts -gfx_backbuffers=0 as a command line parameter, and unless Windows Aero or your graphics settings force additional back-buffers you should end up with just 1.

[Toni Wilen]

Did you try both direct3d and directdraw modes? (also make sure you use latest betas, d3d has been rewritten)

[vrm]

I've already tried adding -gfx_backbuffers=0 to the shortcut but it made no difference.

Using the latest beta, directdraw still had the same lag however for some reason Direct3D is no longer selectable - it's vanished from the list of filters

[Toni Wilen]

It was moved to misc panel (it is not just a filter anymore), read changelogs

[vrm]

ahh there it is
I couldn't get Direct3D to work at all in fullscreen.. only windowed mode.
Fullscreen just results in a black window on the desktop.

[Toni Wilen]

Originally Posted by vrm

ahh there it is
I couldn't get Direct3D to work at all in fullscreen.. only windowed mode.
Fullscreen just results in a black window on the desktop.

Enable logging (misc panel), start in fullscreen mode, wait 10s, exit emulation (for example ALT-F4), attach winuaebootlog.txt and winuaelogt.txt.

[vrm]

got it working.. I only get the black window if I have 50Hz selected (or 59), any other refresh rate and fullscreen works fine. Do you still want the logfiles?

unfortunately the vsync lag is still there with D3D

[vrm]

Attached is the log files for when I launch with DirectDraw, Fullscreen + Vsync resulting with lag.
Not sure if it's useful but I'll do anything to stop this problem it seems I'm stuck with forever

[Toni Wilen]

gfx_backbuffers is not directly supported command line parameter (without -s or -cfgparam)

gfx_backbuffers=1 (try also zero) in configuration file may help with lag.

[vrm]

ok well I have some interesting results..

gfx_backbuffers=1 + vsync -- feels like there's a 'slight' improvement..
gfx_backbuffers=0 + vsync -- lag is gone, perfect!! only problem is that it now runs at 999fps..

is there a setting in between? maybe backbuffers=0.5? probably not :P
any way to get the emulation running at 50fps with backbuffers on 0??

I feel after all these years the solution is getting close..

[vrm]

what do you think Toni?

also what's the difference between Vsync and AutoVsync? Both options produce the same results..

[Toni Wilen]

You have to have at least 1 back buffer but are you really sure it is "full" input lag or just mouse specific? (or keyboard only etc..)

How do you "measure" it?

One buffer only adds 1000ms/50 = 20ms more delay, 20ms (doublebuffered) vs 40ms (triplebuffered) delay should not be that visible. Even normal fullscreen uses doublebuffered mode.

I still think it has something to do with stupid display drivers using vsync busy wait. Try all active priority settings.

Autovsync = automatically select correct rate (50Hz or 60Hz)

[vrm]

I'm fairly certain that it's only mouse movement that's affected.. I can't notice any other input lag.

To test the mouse I just load up workbench 1.3 and move the mouse around, switching between vsync and non vsync modes.. mouse lag is very noticeable when doing so.

Btw, I have tried all other mouse types/modes, disable acceleration, overclock USB etc.. none of that works. Also none of the priority settings make any difference for me.

[Toni Wilen]

Does the mouse have "rubber-band" like feeling?

Afaik I noticed something similar (it was long time ago) if mouse driver had acceleration enabled but I also noticed acceleration was not enabled in all mouse options, only when using "windows mouse", perhaps it is driver/manufacturer specific..

[Mixter]

I agree about the "rubber-band" like feeling. I had same experience.
I also think it is strange it makes 100% CPU in vsync on.

Maybe you can research it further, Toni? Thank you.

[vrm]

"rubber-band" would describe it well.. and changing backbuffers to 1 does reduce it, but does not eliminate it completely.
It does seem worse with "windows mouse" but is still evident using "mouse*"..
I have acceleration completely disabled on my machine.
I've always used a standard MS optical mouse with the default XP driver and now the default win7 driver.

As for the cpu always on 100% with vsync @50Hz, I think this is normal behaviour.. correct me if I'm wrong Toni..