So I'm stable at 4.75, 125x38, 1.36v BIOS, 1.34v under load, LLC Level 2. This also required a slight bump in VTT and PLL voltage (I can't recall the exact voltages). Passed multiple runs of IBT, a little BF3, and plenty of futuremark bench runs. Unfortunately, this ASRock Extreme6 has been giving me trouble since the first power up. - First, no display. So I reseated the GPU, still no display. Unplugged PSU, let it sit, cleared CMOS just for giggles, then display worked? - Random reboots at stock, and oc'ed. Then it would reboot before posting, then after posting, then the issue would just go away... - Ran IBT, Linx, and P95 at 100% stock settings, rebooted during all three within a matter of 30min to an hour. - Replaced PSU thinking that was the issue, nope, same problems occured. - Finally, the motherboard failed to show any onboard lighting and then no video would display. No beeps, no nothing. Just the fans powering on. No way my CPU is dead, I barely put any volts through it, max it got was 1.36v in the BIOS. So the Extreme6 is being RMAed along with the NZXT/Seasonic 750W PSU. I have a Thermaltake 850W that I'm replacing the PSU with, and an ASrock X79 Fatal1ty Pro replacing the Extreme6. I wanted a board with more than 12 power phases, so I went with the Fatal1ty board. I hate that his name and face is all over the box, but I love the expansion port layout and 16+2 power phases. Maybe this board will get me to 5GHz under 1.4v? We'll see.