Iam SO CONFUSED, x800 pro or 6800GT ???

I know the 6800gt is more powerfull in opengl games and the x800 is
better in Directx games, which their are LOTS MORE, 95% of games are
Directx, but dont hold me to that number pulled it out of my arse, but
its somthing like that.

Anyway i wish to run ALL my games with AA and AF, AA 4 AF 8 atleast.
From what i read, the x800 pro does this the BEST AA and AF, and when
you turn on AA and AF on the 6800Gt the frame rates go down to nothing
or not as good FPS wise as the x800 pro.



If anyone can clear some of these points out it would bea GREAT, help
to me.

As i wish to purchase a new card within the next week.

Thanks.

Also i have a Mobile 2500 at 2.5ghz, would one of these cards work to
the fullest on my system ??, pc3200 ram, 400fsb.

Thanks again.