Hi all, I've just got a new computer recently (having some problems with high res stuff as i'll describe later) and it has the following:
Intel Core2Duo E8500 3.1 GHZ Cpu
Asus P5Q PRO Turbo MB
Kingston 4GB DDR2800 RAM
4x Seagate 500GB HDD
Gigabyte Geforce GTX 260 OC (it's not the 216 version either i believe, but core clock 650 etc)
Solytech 600W Power Supply
Enermax Phoenix Case (big fan on the side)
System generally works fine and I can play low end games like Wolfenstein Enemy Territory OK, and do normal browsing and stuff OK. However I also installed Oblivion, Risen, and Fallout 3, and I tried playing them all on 1600x1200 res on relatively high settings (as I believe I should be able to, heh) and after about 10/15 mins on oblivion the textures get weird and discolourations etc, sometimes the game crashes altogether. Same thing happens on risen, except it doesn't usually do anything odd - it just freezes my comp altogether. However in the lead up, the performance is great! it just suddenly stops. Same thing with Fallout 3, it'll work great for 15-20 min then just start to have strange texture issues and weird colours appearing. I've used EVEREST to try and monitor the temperatures and also FurMark to test, and there doesn't seem to be a problem with overheating as far as I know (the case has a massive 25cm fan on the side so I'm skeptical there's a cooling problem).
I've begun to wonder if maybe my power supply's not putting enough juice for my card when i play high res stuff, as I am running 4 500GB HDD's (dunno how much of a difference it makes honestly im no expert by any means). I've looked around on the net a bit and definitely suspect it's a problem with my video setup, but i'm hoping it's not the card (they're all new components, nothing second hand). I also tried one of the rendering things from here (http://www.daionet.gr.jp/~masa/rthdribl/) which some people suggested as a way to test the graphic card. Interestingly, i could only run that for about 10-15 minutes too before i'd lose colours, the entire window would go white or something weird would happen. Wouldn't freeze up my comp or the other stuff though, just the program.
I have tried various drivers and correctly uninstalled every time (manually deleting nv files etc) to no avail. System is clean of viruses and things so I'm abit baffled as to what part (or parts) of my hardware are likely causing the problem.