But when purchasing a Core 2 Duo processor, is it best to spend big and purchase a 4MB L2 Cache version (E6600 and E6700)? And what kind of overclocking performance can you expect using an after market heatsink? Well thats what we are here to find out today. That said, the higher-end E6700 is not the only Core 2 Duo processor that we are going to squeeze some extra GHz out of. The bargain basement E6300 will also have its clock speeds re-worked for extra performance.
While the clock multiplier is completely unlocked on the horribly expensive Core 2 Extreme X6800 processor, it is locked to a certain extent on all Core 2 Duo processors as it can only be reduced. This means the Core 2 Duo E6700 is limited to its default x10 clock multiplier and downwards, so when operating on the 266MHz Quad Pumped (1066MHz) FSB it works at 2.66GHz. With reasonably limited cooling in place however, I was able to easily achieve a 3.66GHz overclock without compromising stability in the slightest.
With reports around the net of speeds in excess of 4GHz, some may see our results as lackluster, but like most of my other overclocking articles, our target is not achieving the highest possible overclock out of a very expensive (water) cooling system, but more of a down to earth increase in speed that can be attained right out of the box. So, while a 5GHz Conroe overclock does sound like fun, cooling systems that could freeze an ice block over the processor in seconds are nice, but for most they are also very impractical.
I was able to boot up at 3.9GHz using the E6700 processor, though the system was very unstable. Even at 3.8GHz stability was still an issue with the XP-120, though I was able to run a few benchmarks this time. For a while 3.7GHz seemed to be the sweet spot, though after long periods of stress testing the system would often come unstuck. Backing the frequency down to 3.66GHz did the trick, as this 1GHz overclock was able to drastically boost performance without compromising stability. Therefore, I believe it is safe to say anyone purchasing a Core 2 Duo E6700 processor can expect to hit at least 3.50~3.66GHz when overclocking.
The Core 2 Duo E6300 in the other hand overclocked another 1170MHz allowing it to operate at 3.03GHz. While this does make the overclocked E6300 significantly faster than a standard E6700 or even the X6800 processor, it still only features a 2MB L2 Cache which could affect performance.
Keep in mind that the E6300 is priced at around $180, while the E6700 should cost at least ~$580. Meaning that if the E6300 is able to even match a standard E6700 once overclocked, it would be an excellent result for those looking at purchasing this affordable processor. With that in mind, lets move on to the results to see how things turned out.