Well, after some more fiddling with the stock cooler I came up with some mixed results. Using Core i7 940 at 3.4GHz (200x17), uncore at 3.2GHz, and QPI at 3.6GHz the system is rock solid 24/7 using just 1.208-1.216V with temps maxing out at around 88C on all 4 cores. Upping the multiplier to 18 yields 3.6GHz with everything else the same, including voltage and can Prime successfully for anywhere between 15-45 minutes. In that time the temps will climb to over 90C and it seems that as soon as that becomes sustained it is only a matter of time before the system will crash. So essentially, 3.6GHz (200x18) with a stock cooler should be stable enough for even gaming as there will be no sustained 100% load on the cores during that time. But, it is a bit of crapshoot. The best I managed to do on stock is boot Windows and run SuperPi at 4.1GHz using about 1.35V. This was not stable for any sustained period of time really. One other thing to note is that my computer is stuck in a corner so it is definitely not in the most optimal setup for air cooling. Furthermore, my room temperature is typically anywhere between 20C-22C which is a bit on the warmer side. I'd expect that with some water cooling I could keep the volts and temps down and quite comfortably get 4GHz-4.2GHz.

This is all done on R2E mobo, with only voltages for core, QPI/DRAM, and DRAM being adjusted. I have not noticed anything else affecting the OC ability for now. I also noticed that the CPU seems to respond better to finer adjustments of voltage on the lower end to get higher clocks than cranking up the voltage. I'm sure this is also in part due to temperatures. Also, Intel lists 1.35V as max, so I am not comfortable going too much past that. Unfortunately, R2E gets not ability to modify QPI and Uncore multipliers so this blows when trying to isolate max stable CPU clock as QPI and Uncore are always playing a role. Maybe this should be a feature request in future BIOS? Who knows...one can only hope...

I was thinking of picking up Swiftech H20-220 Ultima Plus WC kit to cool this better but since I am new to WC, I am not really sure this thing is worth the money...thoughts?