This is turning into something of an adventure Carl. And I don't necessarily mean that in a bad way. Overclocking to even 4GHz on this setup isn't really doable. The machine is nice and stable, even at 4.2GHz or 4.5GHz. The problem is heat. I thought that the Cooler Master V10 would be a good alternative to water cooling that would get me to 4GHz but I was wrong. The CPU goes on a steady heat ramp and after about 10 minutes under 100% load on all six cores the temps get to 85C.
Why am I determined to overclock? Because without it I am leaving a lot of potential performance on the table. Stability is not the issue and the voltage bumps I am using are not particularly agressive. At first I thought that I may have mounted the Cooler Master heat sink incorrectly or it wasn't making good contact with the processor, so I took the machine apart and reassembled it and am getting the same results.
So, as much as I was hoping to avoid water cooling it seems to be the only real choice with these hexacores if you want to squeeze the most performance out of them. I could bump the overclock down to about 3.6GHz and keep the temperatures at ~ 65C. But with water cooling I should be able to get to 4.5GHz. While this might sound crazy I am going to ditch the Thermaltake Armor+ case (a move that Gene will probably applaud) and replace it with a Silverstone TJ07 Black case. The Armor+ will support a water cooling rig but not with the radiator on the inside of the case, and I really don't want a big 120x3 radiator hanging off the back of my machine. The SilverStone can accomodate a radiator on the inside of the case (in fact it can take one three fan and one two fan radiator, so I could go with a dual loop configuation if I wanted to.
--Jerome