you motherboard doesnt have pci express. it has agp. therefore, you have to get an agp video card. the 9800 pro is agp, so thats ok. those should work together well. only newer boards have pci express. yours is kinda old. anyway, pci is a slot that most add-on cards use, such as a sound card or network card. video cards used to use pci, but then they invented agp, which is a new slot that gives more bandwidth. just recently, they invented pci express, which gives twice the bandwidth of agp. however, most people say that it doesnt increase performance at all.