I have been struggling with fedora for some time now. I have a horrendous problem with x. It is so very slow and pooey. Its like trying to play quake on a 486. I have upgraded the software stack and played and fiddled but I cant crack this nut

I would have thought my core2 duo with 2 gb ram would sing. I have a ATI sappire X1650 pro which is using the proprietary drivers to fuel my two 22 inch displays. It was working well but has steadily got worse since I installed fedora8. It worked great on ubuntu 7.10. Any ideas?