Rampage 4 Black edition only showing 3 cores and 6 threads with a 6 core CPU?

I had a water cooling pump failure on a Swiftech H220

Put in a new system and everything booted. Because of the pump failure I did a CPU check. I was running an i7 3960 but it came back as a fail on the Intel diagnostic so swapped it out for an i7 4930k but that to while passing the Intel diagnostic still only showed 3 cores 6 threads. I've just tried another i7 4930K and that too only shows 3 cores and 6 threads.

My next step is to swap out one of the 4930's on my wife's P9X79 pro but does this seem like the sort of failure you can get with a motherboard?

Cheers John

It's highly unlikely that you'd have multiple CPU's that magically lose half of their cores. So there's a better than good chance that somethings up with your motherboard. I'd be willing to bet money that if you put those chips in your wife's setup, you'd get all your cores back.