just upgraded to evga 790i. i have kingston 1333 4gig. but also bought ocz 1600. i can't seem to get the computer to boot windows vista 64 bit with 4 gigs. had no problem with my 680i board and ddr2 800 4 gig. It doesn't seem to matter what voltage or freq. i run it at. Tried various timings. 4 gigs always fails on boot. i'm running a qx9650 at 3.66 11x multiplier with 3 x 8800 gtx. i'm new to overclocking, only been doing it for about a year. i guess i don't understand ddr3. was it a mistake to get the 790i motherboard?