hi

iv just set my new system up with a saphire radeon X1800 XL wich is supose to be a high end card but im having seriose problems with 3d graphic and playing games like far cry and quake 4.
i get these lines across the screen and little gliches all the time makeing it imposiable to play. Its not my monitor or anything i have tried 3 difrent ones (crt and lcd)
i have an amd 64 rnning at 2.2ghz and 2g of ddr.
my motherboard uses the nforce 4 chipst could this be the problem do i need an ati based chipset rather than nvidia.

any help would be great
thanks
luke