Dual monitors FPS problem

[MikZyth]

Hi all!
First of all, I tried searching the forum about this issue, but found nothing. So please help someone.

I have two monitors: Samsung 765MB (primary) and BenQ LCD 21.5" V2200 Eco (secondary). All fullscreen applications (actually games) always run on primary monitor (Samsung 765MB). I made it primary because of refresh rate (with 640x480 res it supports 120 Hz). My BenQ LCD only supports 75 Hz max.
So, here is the problem: when I start Quake 3, it detects my BenQ LCD and runs only with 75 FPS (if r_swapinterval "1"). The same thing if I just started it on LCD monitor. Is there a solution for this problem/bug (maybe this was fixed in some mod)? I run Q3 without any mod (from baseq3).

P.S. Of course, if r_swapinterval "0", it'll show me the illusion of 125 FPS (r_displayRefresh "120"), but this is not the same as real 120Hz.

[MikZyth]

Oh, just forgot to mention: I have two videocards (Radeon HD5670 attached to SAMSUNG and onboard Intel G33 attached to BenQ LCD).

[Eraser]

try setting com_maxfps. It's probably set to 75 and thus it caps your framerate at that amount.

[MikZyth]

com_maxfps "120"
any other ideas?..

[Eraser]

In any case, if your system can handle a consistent 125fps, set com_maxfps to 125.
quake 3’s movement model is a bit wonky where at certain framerates, you can jump slightly higher/further and gain more speed by strafejumping. It helps you make a few jumps over gaps that you otherwise wouldn’t be able to make

[MKJ]

try /r_vsync 0

[MikZyth]

Eraser, thanks for reply. But this is not the solution. LCD monitor can't handle 125Hz and is the weakest part in point of FPS.
Maybe my second (onboard) videocard has something to do with it...

try /r_vsync 0

There's no such variable in Quake 3.

[^misantropia^]

You need to set r_swapinterval to 0. It waits for the vertical retrace. In the worst case (what MKJ probably tried to express)(but failed at) you might end up with only half the expected FPS.

[MikZyth]

^misantropia^, I mentioned that in my first post. r_swapinterval has nothing to do with my problem. It'll just turn vsync off.
What I actually need is 120Hz. My primary monitor (SAMSUNG) is capable of that. r_swapinterval is needed here just to check the actual refresh rate (and there should be 120 FPS).
But 75Hz problem still present...
I hope I made it clear...
Still waiting for help...

[MKJ]

yea im rusty in my q3 console commands
i meant to say, try turning vertical sync off. isnt there a toggle somewhere in the menus?

[Eraser]

Eraser, thanks for reply. But this is not the solution. LCD monitor can't handle 125Hz and is the weakest part in point of FPS.
Maybe my second (onboard) videocard has something to do with it...

try /r_vsync 0

There's no such variable in Quake 3.

It doesn't matter. The refreshrate of your monitor is not tied to the number of frames the engine renders internally. Even if your display refreshes at 60Hz and Quake 3 renders 125 frames per second you'll get the physics benefit of the 125fps. Your monitor will still refresh at 60Hz though.

That's what vsync is about as well. Your monitor redraws the screen 60 times a second if it's at 60Hz. If the game renders 90 frames per second it means that a rendered frame cannot be fully drawn by the monitor until the next frame is rendered again. Your monitor will continue building the image at your screen but now with the data from the new frame. This may cause something called (image or frame) tearing, where you see a visible edge where one frame from your GPU's framebuffer crosses over into the next.

Vsync solves this problem by making sure your monitor completely draws the screen from one frame and when it's ready to draw the next, it reads the then current data from the framebuffer again and fully draws it on the screen. In effect this means you'll get a framerate that's physically limited by what your monitor can handle. This may cause your troubles.

[MikZyth]

I think a little bit of misunderstanding happens here... Maybe my english is not so good, sorry...
You're trying to explain me the basics of vsync. But vsync is not the problem.

In effect this means you'll get a framerate that's physically limited by what your monitor can handle. This may cause your troubles.

This is the case if I run the game on single LCD-75Hz monitor. But I have 2 monitors, 2 videocards, and the game runs on the monitor that's capable of displaying 120Hz. This monitor (primary) is NOT limited to what the game displays. Even with vsync on it SHOULD display TRUE 120 FPS, but it won't (for some strange reason).

This may cause something called (image or frame) tearing, where you see a visible edge where one frame from your GPU's framebuffer crosses over into the next.

Agreed. And until the problem solved I'm stuck to that effect (frame tearing).

[^misantropia^]

Simple test: does it work when you unplug the 75 Hz monitor?

[MKJ]

vsync shouldnt matter because youre playing on the 120hz monitor, but q3 might recognize the 75hz first and set its vsync to that.
hence, try turning it off, or indeed unplugging the 75hz monitor.

[MikZyth]

Finally, I've found the root of the problem. It was related to RADEON drivers.
The point is radeon drivers couldn't correctly detect my old samsung 765MB monitor (and it's technical specs). Using RefreshFix program I was able to fix refresh rate problem.
But here another problem came up: color depth is now 16bits no matter what I set in the config. I'll try to experiment a little with the RefreshFix settings and post here the results.