ASUS Z77 Motherboards - Official Support Thread

[Cecil]

Try keeping the same voltage delta between VCCSA and VDIMM as you increase and see if that helps at all. As for the DDR3-2400 issue, I would set most to the subs manually and see if it helps. Also see if you can get more stability with "receiver" and "transmitter" slew. I am assuming you are using the latest UEFI also.

Going to give this a try. Got two 3770Ks and it still wont post with 2400Mhz, and now 2600Mhz doesnt want to work either. Funny enough, both 3770Ks are the exact same batch.

EDIT: Used the guide in your sig for the second and third timings, no post. Tried adding a bit of VCCSA, no post. Added a bit of PLL, and got stuck in post loop.