   Dual monitor issues
  HiI recently bought two TFT monitors and I'm getting very strange framerates in my game when i use both at the same time. Since the screens run at 60Hz it shows very clearly when the framerate drops. When i switch back to a single monitor it works like a charm though. I'm using OpenGL and have the logic and rendering separate with render-frame interpolation between logic loops. Does OpenGL have issues with dual monitors and can I do something about it? (this doesnt happen in commercial games, they run smoothly)thnx/Mekanikles(sorry if this doesnt belong in Beginners, didn't know if this was an OpenGL specific issue or not)   
  Don't know if it apply to you, but I had similar problem. It's not about OpenGL, it's about SLI. I have GeForce 7950GX2 and in the new nVidia drivers control panel (can't see the option being in the old one), you can select between "multi-display" or "multi-core". Selecting multi-display enable both monitor, but only use one card for 3d rendering (fps/2). Multi-core enable only one monitor, but use full power. I know it's crappy and I hope they find a way to change this dynamically in the future when running game cause it's pretty gay to reboot each time.   ;  I was never interested in the technicalities, but I had problems when running 3D applications in my SECONDARY monitor.  Make sure your app runs in the primary monitor...  Not sure if that helps though as you're saying that commercial games run smoothly, and they probably render in the same monitor you're using to test your app...   ;  You're quite correct xEricx, I do render my app on the primary screen and its just the simple fact that the other monitor is enabled that makes things run badly. And on Dunge's point, it's not that i get my fps cut in half, I get strange lag spikes that makes movements stutter (my fps counter seems ok/stable)I would suspect that this is Windows', alt. Ultramon's fault but since i can run commercial 3d apps smoothly, I'm stumped. Oh yeah, I also did download a freeware game off of gamehippo called "Akuji" and it ran very smoothly so i know it is possible without any hardware changes (though it is possible that this game uses software only, I'm not sure)I'd appreciate any help i can get :)/MekaniklesEDIT: I wish i'd learn to spell me nick right ;-)   ;  Sorry I dont have any help to give, but I'll mention that Introversion Software's game, Darwinia, had strange problems with secondary displays as well. Primarily, particles would render like 100x their proper size (so blinking lights were HUGE and obscured gameplay).They didnt patch it away, but there were two ways to fix it:Disable the second monitor, or go to the config options and change the setting for "z-buffer bit depth". Something in the way it reset teh display after changing that setting would cause things to behave normally.Who knows, maybe theres an equivalent thing you can do..similar to kicking the car to make it start, but hey, if it helps.   