Well, if you already tried that, I'm sh@t out of ideas mate, sorry. It is a common thing with 6x ram slots populated on x58s. You have to drop speed and relax timings. Try your ram at 1066 spd and reboot then work your way up the MHz until you lose ram.
Not even at 1066 theres more RAM to be seen.. Think i'm giving up on this board.. Also, woth to mention maybe; After i installed another 3x2Gb, the computer Restarts one single time before post, every time i Reeboot or Turn on the computer - Maybe this has anything to do with something? The MemOK! LED flashes at the first reeboot, but RAM settings aren't changed.
Can you successfully get 6gb to run at XMP speeds? I'm not convinced it's a fault with either board or ram. It sounds like a compatibility issue. Ideally, you should have bought a 12gb kit of 3x4gb to avoid the issues.
XMP runs great both with 6GB and all 12GB installed - But as mentioned, the board reboots a single time when all 6 sticks are installed.. About what kit i should have bought - RAM's are secondhand for 2 great deals But i guess that your right, looks like some compability issues..
