Overclocking Results

Ok, now lets get to the interesting stuff since now we find out what this nice looking board full of features can actually do in terms of an overclock, Well it turns out this 680i chipset is very limited by the FSB it can run. For both CPUs only a meager overclock was achievable, no matter what the CPU volts. NB, VTT, GTL and SB voltages. After tweaking these voltages and trying different combinations for several days, trying to exceed a particular FSB point, it was noted that the only setting that did much as all was the NB voltage. VTT, GTL, and SB could remain at medium or low settings but if NB was lowered to a level below high the overclock would fail. The 680i chipset is known for having FSB holes, which means at a point FSB will fail, but if you jump as much as 20-30 FSB stability will return. This unfortunately was not the case on this board and one can conclude there are compatibility issues with newer quads and 45nm CPUs for high FSB.

The Xeon E3110 maxed out at 400FSB, using the 9x multiplier that comes out to 3600Mhz, an overclock of 600Mhz. The Q6600 maxed out at 360FSB, again using the 9x multiplier that comes to 3240Mhz, an overclock of 840Mhz. Those overclocks may sound reasonable, however it is important to note that the same two chips were stable well over 500FSB on P35 chipset boards.


For testing the maximum memory clocks, async mode was quite useful for testing as it allows custom memory clocks that are not linked to the FSB bus. There is a drawback to this however since there is a slight performance hit when using async mode as opposed to sync. As a result it is recommended to find the max RAM freq in async mode and test the performance difference between this and the nearest option using sync mode.

Most overclockers know that when running an overclock, it is always better to use the max CPU clock and choose a memory divider that will allow the max RAM clock at this speed. That said, the sweet spot to run the Mushkin 4GB HP2-6400 kit (within manufacturer voltage specifications) and remain at max CPU speed is 450Mhz (DDR900) at 5-4-4-14. This was achieved using sync mode and the 333 RAM frequency (4:5 divider) available in the BIOS. This RAM frequency will be used for both stock and overclocked tests for consistency purposes.