i had the same prob with my adata pc4000 it quit at 295 no matter what ratio. i discovered that the prob was with the gat. it seems (at least with my ic7) the timings related to performance acceleration (or in some mb's game acceleration or gat -pat) really screw up hi speed loose timing ram. after turning off the some of the settings-changing around the rest, i finally got it to run past 295 at 3/2 , 5/4, and 1-1