i used the one that came with the cpu , core 1 was 50ish . but i got problems and i had to reset everything to default changed the jumper back to ddr1333 and im back to 500mhz memory running at 6 6 6 15 .. because i had 2 bsods on 340 and even lower .. so its not worth it .. the 30 mhz inscrease in ram and the boost in cpu speed.. this is getting on my nervs to be honest . i mean the cpu is brand new and i cant run it at the default memory speed of ram .. i even sent to asrock support but i didnt have the seriel number for my motherboard so i guess i wont get a reply ..