Ok, I have possibly made a minor error. My old card (9500 Pro that was modded to hell and back again) got a little toasted and it worked fine for general usage but would really slowdown in games (I think the memory modules got whacked). So I decided to take the plunge. I recently bought a BFG 6800 GT, I said to myself "Hey I'm going to go big or go home." I popped it in and did a few things and I noticed system stability wasn't great. As in it would reboot randomly. So I reinstalled WinXP and got everything up and going. Same problem. If I do a 3dmark03 test it will reboot part way through.
My thought is that the poor little power supply from the XPC can't keep up with the GT. I tried putting the GT on its own power lead and that didn't really help. I can play some games ok (Dawn of War, older games) just fine but things like Doom 3 don't go well. Big lockups and rebooting.
Now there is one "ahem" minor thing that keeps nagging me in the back of my mind. During my "Computer must be silent at all costs!!!" phase I swapped out the fan in the PSU to a quieter yet higher airflow 40mm fan. I also switched the stock heatsink fan to a Vantec Stealth. Things were good but then this summer the XPC started to get hot. I mean really hot. The metal rails were really warm to the touch and during intense gaming it would turn off and the "I'm too hot" LED would light up. I got angry at the situation so I replaced the Stealth with a Delta EHE. Screw quiet... it's damn cold in there now. So its possible I baked the poor XPC a bit.
Well there you have it. Any ideas? I am trying to limp it along as long as I can until I can do a full new system (2-3 months I hope). Oh and I am not opposed to any modifications to the system no matter how drastic (its sort of a Franken-XPC already). In fact doesn't that make it all the more fun?