It also has PSM3, which next gen games will be using. So the X300 will have to be run in Direct X 8.1 not 9
If you wait a little while though, when the next gen graphics cards come out (7800 and X900) than you can save money/get a better card for the same price. The 7800 comes out in 2 days.
Umm, I would think that a PCI-E card would perform better than a PCI card. But thats just me.
EDIT: I did some research and found out that there are no PCI cards for the 6600. It was confusing becasue the links he provided didn't work, so I assumed that the 6600 was PCI.
Should I get the 128MB, or is the 256MB worth the difference? ´Cause someone told me that the x300 is too slow of a card to actually utilize the extra 128mb of memory so it's about as fast as the x300 128mb version.
The top end cards barely need 256mb's of memory. They could happily work on 128mb with no difference/maybe 1/2fps more with DOOM 3 it will make a noticeabl difference.
Tbh. I also think you may as well go for the X300. The 6200 is also the same price, and still as good.