To all:

Heat is not always the limiting factor in OC'ing. The processor needs to perform a logic operation that gets routed through the front side bus to the memory and back to the processor.

We try to crank out the FSB to get that cycle (measured in Hz) to move quicker, but if the result comes back before the processor is ready, you will get a logic error = system crash, or lockup. This can happen at the limit of the processors core architecture even while heat isn't seriously high.

Chips are manufactured in 'bins' and some will be created better than others.

Intel or NVidia can't possibly sell only Core 2 Extremes or 280GTX's because the market isn't large enough for high end stuff. So even if 80 out of 100 die's meet the specs to become a high end processor, they won't use all 80 for that purpose, some will be thrown into a lesser setup so that they can still turn over a profit.

So those of us that get these lucky gems, can get unbelievable overclocks, and those that get stuck with the bad die's may not get much. Manufacturer's usually have a specified minimum margin for any given chipset, so that they can still run at their rated speed in a worse case scenario.

Generally OC'er try to control the environment the processor is faced with (more voltage, better cooling, better supporting architecture, etc.) and can run to the higher end of that margin.

So don't be upset if you can't crank that mofo up, even if it seems like it's not getting up to any detectable limit.

And while a huge gain sounds good and looks good, silent corruption can still occur, so if you're doing work, best to keep that margin that the manufacturers left, or at least some portion.

Just my two sen.