Hi, i have a gigabyte ud5, 2600k and 2*4 vengence memory. I have recently built this rig (not overclocked yet). The memory auto runs at 1333mhz and i have been trying to get it to run at 1600mhz. I have set to xmp in the bios and it changes to the right speed but will not boot or boots ocaisionally. My pc is rock solid stable otherwise. I have tried it with the old bios F2 and the latest F6. This is not a B3 board. Oh, and i have but the timmings in manually to (1.5V). I can not wait ot overclock but want to sort this issue out first. Please can you give me any help or advice on this matter. sooooo frustrating.