I think you are looking at the wrong graphics card for that processor. You will always be bottlenecked by the processor.
If I were you I would look at a 4670 or a 9600gt. Unless you already have that card, or can get it really cheap. (less than the other two I mention above). But if you already have it, it should work with the PSU.
Actually I am pretty surprised at how well the Pentium D is doing. I have it overclocked @3.6GHz and it's pretty fast. I doubt it'll be a big bottleneck.
Also I only game at 1280x1024 and I am just looking for something that can run most games on high at that resolution, with maybe a little eye candy. I have an 8600GT right now and...to be honest it's terrible even at a low res like that.
I can get either an 8800GTS 320 or an HD 3870 for cheap. They are similar in performance so I just need to know if they will run on that PSU.
I wasn't knocking the Pentium D...I still have a system that has one also @3.0, and it does pretty well at low resolution gaming with a basic video card. My point was at low resolutions you are actually more cpu dependent than you are gpu dependent. With modern games with higher demands you may see very little gain, even if you went to something like a gtx260, because you might be at the limits of what your cpu can output to the graphics card.
Ok, I gotcha. To me it doesn't make a huge difference because I can get the card extremely cheap (less than $40). Plus the next upgrades I'm looking at are a new CPU and a new monitor, so it might be worth it to get something a little bit stronger for the time being.
I am just glad to hear that the 8800 will work on that PSU.
as jsc says, it is kind of close, but my quick calculations showed it working assuming the PSU was reasonably efficient. I don't think you risk any serious damage by trying it, as he pointed what will happen if you are under powered is a quick reboot when your gpu hits a hard load...
Sorry, not familiar with that card at all...but I did want to say if you do have to upgrade PSU you should go overboard and get a quality 750w or so. Unlike most other things in a computer you can always move the PSU from build to build, so assume it will be with you a very long time (and the prices don't go down like on most things) and buy accordingly.
Of those two cards, I would defiantly chose the 3870.
It is slightly faster (about the same as a 8800GT), draws less power (~105w vs ~145w for the GTS) and has more RAM.
I am not sure if it will work with your current PSU. ATI Recommends a 450w+ PSU for this card.
If it works, you should probably start saving for a quality 450w+ Corsair, PCP&C, Seasoinc, Enermax or Antec Earthwatts PSU.
DO NOT get a high wattage, low quality unit!!
They are not capable of outputting their rated power and what they can output is not clean power.
Avoid low quality PSU's at all costs.