graphics card questions

i got a new graphics card today(ATI 9800XT). on the back of my box it says: max 3dresolution-2048x1536x75hz. smoothvision 2.0, trueform 2.0, smartheader 2.0, & hyperz III. can anyone tell me what shader model 3.0 is? can i still play new games even though i dont have shader model 3.0? also in bios what are these: agp fast write, onboard game port, serial port address?? do i need to turn these on after i install my graphics card?? thank you