Okay.. I recently upgraded to an 8800gt from my previous x1950 pro gpu, and seem to be having a little issue. While playing Call of Duty 4, after about 15-30 minutes of gameplay my computer freezes and has issues starting back up. With the previous x1950pro gpu i had no problem running Call of Duty 4 and I'm guessing this is related to my power supply. I'm currently running on a Corsair 450vx and I thought that it would be ample enough to run the 8800gt? other system specs include 2gb ram, e2160 OC to 3.0, windows xp, and etc.. Heat doesnt seem to be an issue because my monitoring shows it never exceeds 65 celcius.. Anywho, I'm stumped right now, please respond with suggestions.
I would agree with your suspicion of the PSU. Although 450W is plenty for your system, that PSU probably isn't giving out 450W. How old is it? A PSU that's a year old will supposedly lose 10% of the performance.
Get a new PSU, one that's rated at least 500W, but I'd go with 550W or higher just to be safe. Also get one that has enough amps on the 12V rails.
I doubt it's the PSU that's causing this if the X1950 Pro works fine.
The 8800GT doesn't consume much more power than the X1950 Pro. Barely 10-15 more watts.
I know for a fact that the 450VX is more than good enough for your setup, as my friend is running a similar setup to yours on that same PSU with no problems. Your whole system should barely be using 300W.
However, one can never be sure, components go bad with time (although Corsair is a high quality brand so it's doubtful but possible), so I'd suggest you try swapping the PSU for another one to make sure it actually is the cause of this problem before going out and spending money on a possibly unneeded new one.
It might be conflicting drivers that are causing this. If you haven't uninstalled your previous card's drivers correctly or fully, you will have problems.