ATi Xpress 200

hi. first please excuse my nooby naive. im not a comptuer expert but im learning via asking.

well anyway, my motherboard (MSI Albatron somethin-rather) has the ati xpress 200 chipset. (capable of running crossfire) now i know it contains an IGP (it took the quick way to hell...slapped in my x800xl 512mb) but i know it does more than just provide an IGP. what are the other tasks that a gfx chipset, such as the xpress 200, have to do? and if anyone knows, how does it compare in terms of like the nforce 4? thanks!