Overclocking
Our experiences overclocking the Core 2 chips have pretty good in general so far. The X6800 was running along quite nicely at 3.68GHz, stable as a rock, before we started this Kentsfield review, and the E6700 overclocks very well also. We have read numerous accounts of these chips hitting around 4GHz pretty stably, and the SuperPI world record was recently broken by an infamous chap named “Coolaler” who overclocked his E6700 to 4603MHz. However, the thing that people sometimes don’t consider when talking about how well a chip overclocks is the motherboard that is facilitating the overclocking. Unfortunately for us, the two main motherboards we have overclocked the Core 2 chips with have been the Intel 975XBX, versions 1 and 2. While version 1 could hold its own in terms of maximum overclocking potential, version 2, the one that is apparently the only one that will work with the QX6700, has a ton more options and a much better BIOS layout that version 1. However, there is an FSB wall on the motherboard that will not allow processors to boot with FSB speeds above 279MHz. This is EXTREMELY frustrating, as right off the bat it was clear that the QX6700 had some serious potential. How did we discover this potential, you ask?

Well, we raised the multiplier to 11 right after we installed it to see if it would boot fine at X6800 speeds. It booted perfectly and was just as stable as at stock. Then, we bumped up the multiplier to 12, for a clock speed of 3.2GHz. It booted perfectly fine here as well, and was very stable. Then, we bumped it to 13. Very rarely does an Extreme Edition processor take multiplier bumps this well. It booted at 13, but had some stability issues. Up to this point we had not raised the voltage or changed any other settings on the board. We had to push the voltage up to 1.4875V to get the system very stable at 3.47GHz. Then, we reverted the multiplier down to 8, set the RAM frequency to go 1:1, and got ready for what we expected to be some serious FSB overclocking fun. It didn’t turn out that way. The max we were able to get to was 279MHz. The system would not successfully boot at 280MHz; it wouldn’t even try. There was no other possible reason the system would not boot at this frequency, considering at 8x280 the processor would be running far below its stock speed and the RAM would be running at less than ¾ its rated ability. Messing with the voltages, fiddling with RAM timings -- nothing would make this system work with an FSB of 280MHz. These results were repeated on the X6800, which had been to well over 300MHz FSB in the past on the Bad Axe revision 1.


While it is a shame that the Intel X975XBX2 has this deficiency, the maximum overclock of 3630MHz we were able to achieve on the QX6700 is extremely impressive. That is nearly a full 1GHz overclock, and for those number freaks out there, is just above a 36% overclock. Theoretically, when the QX6700 is running at 3630MHz (and it does this stably, mind you), it has just over 14.5GHz of processing power. Yeah, 14.5GHz. Folding on 4 cores, anyone?