God I hate the Corsair XMS2 Twin2x2048-6400C4 ram, first they're not Micron D9 ICs, even though the first 2 versions of the same model were, the newer ones use PROMOS ICs. They're not worth the asking price, plus the price went from $306 with $40 instant savings a month ago, then rapidly dropped in price, all the way down to $260 w/o any sort of instant savings or rebates... just yesterday they were $300 with $40 mail-in rebate, now they're $328 with $20 instant savings and $40 mail-in rebate?? Just choose a different brand of memory, like G.Skill, get the 2gbhz DDR2 kit.