Most probably too late, but I'll post.
mmh...first let me tell you that I'm wondering how that works. You write you have an Asus P4P800 board? So its a 478Socket. As far as I know they all have AGP 8x.
BUT I'm from Europe and MX is not existing here.
So lets come to the important part:
You write "PCI". But is it really PCI or maybe PCI-EXPRESS.
Because if its PCI your board is more for working than for playing.
I'd dare to say, then you should invest in a new board, like ASUS P4P800 DE. Its the 478Socket which is not longer produced, so cheap to get AND it can carry 3.2 Prozessors from Intel.
Generally, its still not necessary to upgrade systems to PCI EXPRESS.
So take such a board and a good old AGP 8x Graphiccard like an ATI RADEON. They are best performing with this boards and just by the way is AGP still the bottom of game-programming, not PCI.
But b4 I'll write to much I stop, cuz you will already have bought one.
