I just built a new PC, 6400 OC'd to 3.2Ghz. Got a 7900GT OC'd as well. 2GBs of XMS2 RAM.

I also have Vista Ultimate.

So, is it a fluke that every game I try to play runs like absolute crap, compared to my older PC which had XP Pro SP2?

Thoughts?

Can't really give a good comparison, since I had a major change in hardware from my other system. I can't really say I've had too many issues with newer games and old games.

Though with the new overhead your hardware has, it's not really surprising that you'd see some loss. But games running like "absolute crap" is a little weird. Try turning down some settings. Could help.

Don’t know about Nvidia cards but I’m using an ATi card and the difference in games like Half Life 2 and Battle Field 2 are somewhat minor. It was possible to see a very slight difference (about 4fps out of 60fps(ish)) after playing CS:S on XP for a while then suddenly switching but after a few minuets you stopped noticing any difference.

I do know though that the ATi are doing a better job with their Vista drivers than Nvidia, but I don’t know if this is related to your problem. Oh and just a side not I’m using Vista X64 and my GFX card is a X800XT 256MB with 2GB’s with a single core 3500+.