Performance in HL2 with 2900XT.(help)

It's horrible. I get great framerates in Bioshock, World in Conflict, and Oblivion but when it comes to performance in my steam games, HL2, HL2DM, and GMOD10 are all around 10-18FPS. It's really pissing me off. I was doing better with my X1300XT. What's worse, no matter what settings I change, it'll just look horrible and play terribly. I have yet to get to try DOD, CSS or Team Fortress 2, but I will guess they suffer the same way. anyone have any idea why this is happening?

I'm also running with 2GB of ram and a 2.4GHz 4600+ Processor.

Compared to HL2, DODS runs fine at a tolerable 25-35 FPS. Hopefully a patch is released soon for the rest. I'm a CSS/Gmod NUT.

Also, just found the Rage3D forums...it seems most people complaining about Source game are complainging more about errors than framerates, hopefully both will be fixed.

check your drivers and that stuff. I run HL2:Ep1 with 80 FPS.

Well, I used to think running catalyst in the background messes up your FPS, but it seems it fixed Gmod 40-60FPS, I have yet to try HL2, but CSS is actually 60+. Team Fortress 2 is running great, but has a few problems....think BAD.