Thanks mate, you have been very helpfulAfter a quick run the usual crap (like Cinebench), surprisingly World of Tanks. Anything that's missed by 3D Mark etc is always been picked up by it crashing.
I do not touch Prime as is completely crap and archaic method.
Will report back my findings. Right now I am going to run a few more tests to see how stable my 4GHz profile is before I move on to the RAM, as right now my system has been rock solid when running ram with XMP.