Found a safe/low-temp overclock @ 3.6Ghz for this board. Using 1600Mhz DDR3 RAM. standard air cooling in a z-machine GT1000 case.
RAM set to XMP profile #1. 8/8/8/24/1.66V/1.35v
BCLK:180
PCIE:100
Speedstep/turbotech:enable
RAM:~1450 Mhz
CPU Volt:1.25V
QPI/DRAM:1.35V
DRAM bus:1.66v
everything else auto/default
CPU Fan and chassis fan set to Standard profile.
44c @ idle. 66c under orthos CPU stress test. The 1.25 CPU voltage keeps the temps nice and low, and it's very stable. the 920 does this o'c with ease, could probably go lower but stability is more of a priority for a software dev PC.