Overclocking greatly varies due to what hardware is being used and
who is doing the overclocking. Always remember that no two pieces of
hardware will perform the same, so our results will differ from what you
might be able to get. The Thermalright MUX-120 CPU cooler was used for
overclocking as the retail boxed cooler wasn’t up for the job when it comes to overclocking.
Here is a CPU-Z v1.54 screen shot of the Intel Core i7 875 K
processor to see what we are going to be overclocking. The processor
has a base clock of 133MHz with a multiplier of 24 (in turbo mode); that
is good for 3.2GHz.
With everything left to default in the BIOS and by just raising the multiplier we
were able to reach 3997MHz in a matter of seconds. The system was rock
solid and the memory kit was running at an impressive 1600MHz as we didn’t have to adjust the base clock or any other settings.
Our maximum overclock turned out to be 4.49GHz that was obtained by a multiplier of 33 and a base clock speed of 136MHz with a core voltage of 1.45V. How does this overclock on the Intel Core i7 875 K processor compare to the Intel Core i7 870 processor from last year?
In order to reach the highest overall clock frequency we had to drop the memory multiplier down by one level and pushed up the base clock to 180MHz with the turbo multiplier of 24. This is an overclock of more than
1.1GHz, which meant we were running 4.33GHz. This means we were able to get an extra 160MHz out of the Core i7 875K that we were able to get from the original processor with the same exact stepping.