I can't seem to oc my 2600k CPU over 4.6ghz on my gigabyte p67a. I'm using a custom cooling system a triple rad for the CPU alone. Tried everything reseted the bios , bios update played with almost all of the bios setting .i ran my pc On prime 95 for 24 hours on 4.6ghz but if I tried to go for 4.7ghz it wouldn't boot up. It doesn't make sense for me at all ... At 4.6 ghz it's solid rock stable ...4.65. No post :s .... Please anyone
That's what they call the "multiplier wall" on the new Sandy Bridge CPUs. Every one of them has a point at which nothing can make it go to the next multiplier -- not more voltage, and not more cooling.
If you really want to get it past 4.6GHz, you'll have to see how high the BCLK can go.
That really doesn't give anyone enough information as to what the problem might be. If you could post the Bios vcore and load vcore and
what you have changed in the Bios with exact settings we might be able to help.