i use a q6600 on my RF and its perfectly fine, i run it at 3.45ghz for every day stuff with 430MHz FSB and 8x multiplier. I never went to a 45nm quad core chip because personally the benefits of sse4.1 can't be utilized all that much yet since not much code has asm optimizations added to use the extra registers. I run 1.43-1.44v through it 24/7 and it hasn't missed a beat for the last 15 or 16months. If you want really high clocks definitely go for a dual core, but I've found a quad core running at 3.4-3.6ghz is much faster for compiling, encoding and even simultaneous drive defragmenting than a dual core even running at > 4.5GHz could ever be. In other words if you don't need the full use of a quad core, you will probably see more benefits from a higher clocked dual core. It has nothing really to do with gtl or anything else, the VRM on the MF/RF struggles at 500MHz FSB for a quad core, so if 500Mhz FSB and up is your goal then either of those boards aren't suited.