the diff between oem and retail is, oem is used by computer retailers that make their own systems, and retail is bought at a store seperatly. the main diff is that one has a box and the other one dont. if the card comes with games you probably wont get them with oem ither
Do some research. ATI has a habit of selling OEMs that are clocked slower. The better chips go to the retail versions. I know that was true of the Rage 128 cards, dunno about the Radeons although I do remember seeing something about that over at http://www.hardocp.com/ a while back.