so just to be clear this isn't a system issue i will give a list of my hardware intel core i5 750 running at 3.3 ghz cpu gigabyte GA-P55M-UD2 motherboard 4gb corsair dominator xms3 1600 mhz ram Nvidia gts 250 1gb 450 corsair psu liquid cooling with 120mm radiator
so, my computer is a custom built one from ibuypower and i've run into some trouble with it, when i boot it up and start to play a game, the framerate is excellent(nfs shift at over 90 fps), but for some reason, after about 20 minutes of gameplay, the game crashes and when i restart it, the game now runs at 12 fps. WTF i haven't got too many computer games but to be sure i went on cod mw2 to try as well and its the same issue, around 120 fps on a normal day but it just laggs to 20 after turning the computer on for more than 20 minutes. i have no idea how this happened, still tweaking around the bios looking for an answer, would be great if you guys could help!
More aboutproblem graphics card
have you overclocked the gts 250?
i did but reverted the changes to the lowest settings and there is still no improvement, it's like the graphics card is on a continuous idle process
a noticable thing is that gpu-z picks up that my card runs at 300 mhz core and 600 mhz shader and 100 mhz memory when the slowdown starts
so when you reboot it automaticlly underclockes your card, that sounds like an overclocking software issue? maby you should check all your softwares for overclocking, maby you should uninstall and reinstall you drivers.
ah well now that you say that, this happened after i installed the v195.81(i think) version of the dispay drivers i'll try again with fresh drivers
another thought, flash you video card bios. maby one of these will work.