   Finding the bottleneck?
  blah   
  Well it's hard to guess, but it seems more like an environment issue if it only runs fast on your machine. Maybe you are ending up in Microsoft's software implementation. Add some code to log the vendor string to a file and run it on all three machines, if the vendor string says Microsoft then that will be your problem. Another possibility is that they have a different version of some DLL that your app uses. You could run depends to see what is being loaded.Does the game look the same on their machines as on yours?   ;.;  What system are u using? What system are they running on? (If you know), then it'd be possible to detect issues and problems faster. Anyway Vista had (maybe it still has) some BIG PERFORMANCE ISSUES with OpenGL apps (It happened on my own machine, when i tried to run own apps under Vista (OpenGL apps)).   ;Quote:Original post by Kada2k6What's so funny is, that every person who playtest my game gets about 15-30 FPS on their machines, and I just can't understand why? Recently, a person with dual core and Geforce 6100 nforce 430 tried my game, and he was getting a ridiculous ~13 FPS.That shouldn't surprise you. A 6100 is already a couple of years old AND it's the lowest, slowest, cheapest one you could get *at that time*. Therefore, any half decent video card that was top of the line a few years ago will explode it in performance.Y.;  Kada2k6: If you're prepared upload it, I'll test it on a couple of boxes I'm running. I'm sure many other people will test it for you as well. :)   ;.;  As per the tests:Intel Core 2 Quad CPU Q6600 2.4GHz2.75GB ram (max possible on a 32-bit system).Geforce 8800GTX 512MB.Average FPS on max settings: 500Dual Core Intel Xeon 5160 3.0GHz2.75GB ram (max possible on a 32-bit system).Geforce 7600 GT.Average FPS on max settings: 220HTH.   ;  If you wanna test it on several ATI cards (including Radeon HD 2900 XT), let me know ...   