I have a IBM ThinkCentre S50 8429-KG7 (its old I know, i swear this is not my fault) anyway i need to upgrade the graphics adapter and i have an integrated Intel (R) 82865G Graphics Controller! According to the manufacturer's website (http://support.lenovo.com/en_US/detail.page?LegacyDocID=MIGR-53415) i have two PCI 175mm length, 106.68mm height slots... so can i upgrade? and if so is there any particular specs i need to pay attention to if i am to find a graphics card?