I recently got a Radeon 8500 64Mb for Christmas. So far I can play every game I have ever wanted too! However, its only at 250/220 for default clock and memory speeds. Supposedly, the default speeds are 275/275, I tried o/c'ing them to these speeds however, I instantly get artifacts on my desktop. The card is made by Apollo and has EMST Memory on it. The core is a R200. Should I RMA it or keep it?