As we found when first testing Intel's Sandy Bridge processors, those wanting to overclock their LGA1155 processor will have to spring a little extra for the K series. This platform does not respond at all to base clock overclocking and is entirely dependent on the clock multiplier. Since the K series are the only processors to feature an unlocked multiplier, they are the way to go for overclocking.
With an unlocked K-series processor, breaking the 4GHz barrier is no sweat for these P67 motherboards. In fact, all but the MSI P67A-GD55 were able to surpass 4.6GHz with the Asus P8P67 Deluxe maxing out at 4692MHz followed by the Gigabyte P67A-UD7 at 4646MHz. We were impressed to find that even the ECS P67H2-A2 reached 4600MHz. The results were astounding to say the least.