I'm having trouble with the ATI Radeon 7000, AGP. glxinfo tells me that dri is enabled and active, but when I run glxgears, I can't get more than 300 fps, and I know I should be getting more.
My system has a 2.6 GHz P4, and 512 RAM, so I don't think any other part of my system is bringing performance down.
I ran Quake3 on linux and my frame rate was about 1/3 of what I get under windows for the same map and settings, on the same machine!
I've looked all over the net and have now come here because I can't find answers anywhere else. Has anyone else had these sorts of problems? is it just that this card has major crap support under linux?

That card you have is actually a nice card with crappy drivers. ATI only started supporting linux(halfway) at the 8500 series and up. And really- they still suck. If you want a good 3D card on linux, get an Nvidia GeForce 4200 or higher. Higher, being preferable. 5950 or 6800GT being nicer options.

But, if you are poor and no relatives are going to die anytime soon, then I guess you may be out of luck this round. Sorry.