50Hz sync -> mouse delay

[Groundhog]

I set my monitor at a refresh rate of 50Hz to have smooth scrollings. They are.

But it seems that whenever I tell WinUAE to wait for the vertical retrace (Fullscreen+VSync), there's a little mouse delay.

Is there a way to correct that ? Without VSync, some frames are lost and the scrolling isn't so smooth.

[Toni Wilen]

Try adjusting priority setting (below normal or normal).

[Groundhog]

Thanks for the suggestion but, unfortunately, no luck.

Another idea ?

EDIT :

By the way, is someone else experimenting this problem ?

[alexh]

You mean "experiencing".

Nope. I get no noticable delay.

Edit: Obviously the mouse responds quite differently in terms of acceleration and precision to the Windows mouse. But that is just normal and depends on your Windows and WinUAE settings

[Groundhog]

Yes, "experiencing", sorry.

That's odd. No matter which config I choose, once I select VSync, there's a delay.

Could you compare with VSync on and off ? The difference is barely noticeable.

Edit : BTW, I worshipped "Chambers of Shaolin" when I was a kid.

[alexh]

I am using a 50Hz screen mode, dunno if it could be that?

I've not heard from Marc Rosocha (the main guy behind CoS) for a few years. He had some success on the Atari Jaguar and Nuon systems with his Iron Soldier series

[Groundhog]

Damn, you're fast.

Well, as I explained, me too. Maybe I'm just short of a few milliseconds.

Edit : Didn't see your edit.

"Obviously the mouse responds quite differently in terms of acceleration and precision to the Windows mouse. But that is just normal and depends on your Windows and WinUAE settings"

I know that. But there's a little but noticeable difference when Vsync is on or off.

[alexh]

No noticable difference between Vsync and non Vsync.

A500+ Quickstart, Full screen + Vsync, double line mode, no filter, 720x576@50Hz

P4 2.4GHz Northwood.

WinUAE 1.4.6

[Groundhog]

Too bad. I'm out of luck then. If somebody has an idea, please share.

Originally Posted by alexh

I've not heard from Marc Rosocha (the main guy behind CoS) for a few years. He had some success on the Atari Jaguar and Nuon systems with his Iron Soldier series

I don't remember this name. That's a shame I know. A talented guy anyway.

The only name I remember, because I'm a great fan of him and I'm a musician myself, is Jochen "Mad Max" Hippel. The CoS tunes rocked.

No news about him ?

[alexh]

I saw him at xmas 2006 and see him online all the time.

[Groundhog]

Originally Posted by alexh

I saw him at xmas 2006 and see him online all the time.

OK man, now I don't remember why I started this thread.

Friend with a god.

I know this is idiot but I would kill for an autograph of him. I'm really a BIG fan. IMHO, Jochen Hippel & Rob Hubbard are the best composers on computer ever.

Lucky guy.

I think this is just a symptom of Vsync, 3d games also get a slight lag with vsync but you can solve this by reducing the amount of frames the card renders ahead.

Dont think this option affects 2d stuff though

[Groundhog]

The case you're describing is when your GPU is working (the "hardware computing"). Here, the software is causing the lag. There's no 3D computation, just some basic 2D blitting, so you don't need to tell the card to reduce the amount of frames to render ahead.

If we had a similar problem here, that would be an option in WinUAE, the software.

And I don't think that this has something to do with power. My computer is fast enough : Q6600 overclocked at 3.6Ghz. (I don't want to brag like a child, just to give precisions.)

So, any idea to correct the problem ?

[Toni Wilen]

Mouse lag has been reported multiple times. More commonly it seems to happen when JIT is enabled and priority is higher than normal. (=WinUAE is using all available CPU time)

Unfortunately (or fortunately?) I have never seen it. It seems to be PC/Windows version or mouse type/driver specific "feature".

[Groundhog]

Originally Posted by Toni Wilen

Mouse lag has been reported multiple times. More commonly it seems to happen when JIT is enabled and priority is higher than normal. (=WinUAE is using all available CPU time)

Unfortunately (or fortunately?) I have never seen it. It seems to be PC/Windows version or mouse type/driver specific "feature".

Really ? Damn.

Then, I must report the fact that I'm using Vista x64 and that the problem appears even when JIT is disabled. Also, as I said, I'm using a quad-core cpu. My GPU is an ATI Radeon x1950pro (up to date, but there are reports that this card generates a lot of problems - I didn't experience any, but who knows...).

Hope it will help you catch the problem.

Thanks for the info.

[alexh]

Originally Posted by WDeranged

I think this is just a symptom of Vsync, 3d games also get a slight lag with vsync but you can solve this by reducing the amount of frames the card renders ahead.

Tearing (where the frame currently being rendered is displayed before rendering is finished) sucks especially in 3D games. I prefer to lower my resolution / quality rather than have vsync off.

[Photon]

Someone who cares about lag from input to output! (I. R. Baboon make victory dance)

Vsync waits until the next vertical refresh to switch buffers (to avoid tearing), while Vsync off does not, giving tearing - if the game fps differs (even slightly)from 50 Hz. No way around that.

I'm assuming you're not using a LCD display. I have a $1400 LCD display and have found no way of displaying any game or emu without lag. I guess it's partly buffer electronics in the display and partly the black-to-white specs of an LCD screen. Also, LCD screens normally do not sync to 50Hz, I assume you're emulating a PAL Amiga.

Me, I run WinUAE best with Cycle-Exact, No VSync on a CRT display that can go 50 Hz. Then the lag is reduced to an absolute minimum, 1/50 second (from emulated code to pixelbuffer - to pixelbuffer drawn by display)

I think the delay could be made 1/100 second, but only if cycle-exact is off and the PC is fast enough to render in 1/100 and display immediately, rather than wait for next 50Hz refresh. It doesn't seem to be the case - but maybe I'm wrong?

[Groundhog]

Originally Posted by Photon

Vsync waits until the next vertical refresh to switch buffers (to avoid tearing), while Vsync off does not, giving tearing - if the game fps differs (even slightly)from 50 Hz. No way around that.

Did I give you the impression that I didn't know all that ? You aren't the only "oldskool demo coder" here.

Originally Posted by Photon

I'm assuming you're not using a LCD display. I have a $1400 LCD display and have found no way of displaying any game or emu without lag. I guess it's partly buffer electronics in the display and partly the black-to-white specs of an LCD screen. Also, LCD screens normally do not sync to 50Hz, I assume you're emulating a PAL Amiga.

My LCD screen can go as low as 50Hz. That's the reason why, when VSync is on, the timings are good and the scrollings are smooth, and when VSync is off, the timings (and so the scrollings) are still nearly perfect.

BTW, I didn't ask for any explanation. My question was : how can I remove the mouse delay ? Nothing about screen tearing or a detailed explanation about screens. I'm not impressed anyway.

Originally Posted by Photon

Me, I run WinUAE best with Cycle-Exact, No VSync on a CRT display that can go 50 Hz. Then the lag is reduced to an absolute minimum, 1/50 second (from emulated code to pixelbuffer - to pixelbuffer drawn by display)

I think the delay could be made 1/100 second, but only if cycle-exact is off and the PC is fast enough to render in 1/100 and display immediately, rather than wait for next 50Hz refresh. It doesn't seem to be the case - but maybe I'm wrong?

In short, I won't limit myself to 'cycle-exact only' configurations. The problem appears as soon VSync is on, cycle-exact enabled or not.

Recapitulation :

With VSync on : smooth scrollings, mouse delay.
With VSync off : not so smooth scrollings (still 50Hz, just not exactly), no mouse delay.

And please, don't assume your interlocutor doesn't know unless he tells you. Thanks anyway for your help.

And for you only, IMHO, the problem comes from the way WinUAE communicates with the mouse driver. Maybe the interruption/polling frequency is too low/too high with some system configurations. Well, that's just speculation. I don't know how WinUAE is coded.

Even if it's marvelously coded. Thank you so much WinUAE !

[alexh]

Yeah, I think some gfx card drivers fake the vsync.

I have nVidia here and no delay.

[Tony Landais]

I don't have mouse lag with vsync neither in 50Hz or 60Hz with my ATI x1600 mobility radeon.
But I have a serious keyboard and joystick lag particulary notisable with Shadow of the beast and slamtilt... they need a much better response to be playable in my opinion.