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.
Overclocking with the new Sandy Bridge processors has been simplified, at least in part. Adjustments to the Bclck have been almost done away with and overclocking is almost completely done through increasing the multiplier. When overclocking we used to run out of room on the Bclck or cooling. Now we are going to be limited by the Multi-wall. The Sandy Bridge processor just isn’t capable of going any faster, it’s all dependent on the piece of silicone that you get when you purchase your processor.
The Intel Core i5 2500K utilizes a bus speed of 100MHz, though the MSI P67A-GD65 is picking it up at 99.8MHz. Under full load the Intel Core i5 2500K uses a multiplier of x33 to achieve the final clock speed of 3.3GHz. Since we are using a K series processor we will be able to increase the x33 multiplier until we hit the multi-wall.
With a quick press of the OC Genie Button on the MSI P67A-GD65 we were able to bring the Intel Core i5 2500K to a rock solid 4190MHz by using a x42 multiplier and the base Bclck of 100 MHz. That is a gain of ~900 MHz or 27.3%.
When I first started overclocking the Intel Core I5 2500K processor I left all of the settings on auto. We were able to hit the identical overclock of 4824MHz as we have seen previously. We hit that overclock with a x48 multiplier and a Bclk of 100.5. With a quick flash of the BIOS through the MSI M-Flash utility we brought in a new BIOS with a new feature! This new feature is the Internal PLL Voltage. Once this was enabled we were able to push the Intel Core I5 2500K further than we were previously able to. I was able to boot into windows with a multiplier of 51! Once we did anything though, we got to see the infamous blue screen of death. Eventually we had to settle for a x50 multiplier with a 101 base clock. This gave us a final and impressive 5.05GHz overclock!
Running the MSI P67A-GD65 at 5050MHz we saw some hefty improvements in our wPrime scores. Running the 1024M tests we dropped an average of ~114 seconds or a 32.7% drop in time across the three runs. The 32M test dropped an average of 3.9 seconds or 34.5% across all of the runs. Not a bad performance gain with little work. If you happen to have the MSI P67A-GD65 and the Intel Core i% 2500K and want to try the BIOS settings that worked for me, you can find those settings here.