By default the Core i5-2500K has a clock speed of 3.3GHz. Many people have heard that overclocking Sandy Bridge processors was hard and that it would be impossible, but actually it could not be easier. The first thing you need to do is go into your BIOS. With the MSI P67A-GD55 you have the new Click BIOS so that makes things even easier. You will first need to go in to the OC settings. You will notice that you cannot change the CPU Base Frequency of BCLK as most of you know it. This really makes things easy as you just need to adjust the CPU ratio to overclock the CPU.
By default the CPU ratio is at 33. I first moved it up to 40 to get the CPU up to 4.0GHz. This was done without any other adjustments. To test how stable the system was I ran Prime 95, 3DMark Vantage and Super Pi all at the same time. After I knew the system was stable I started moving up in 100MHz intervals. I got stuck at 4.4GHz, but then I upped the CPU voltage to 1.3V and that allowed me to get up to 4.5GHz stable. Not a bad overclock at all at 1.2GHz!
One really cool feature that this motherboard has is OC Genie II. What that does is automatically overclock the system for you. Just press in the OC Genie button on the motherboard and restart your computer. When you turn it back on it will be automatically overclocked! For our specific system with the Core i5-2500K it overclocked it to 4.2GHz from the stock speed of 3.3GHz.
This is great for people who do not want to mess with the BIOS and really don’t know much about overclocking, but still want to get the most out of their system.