I am sure I fixed the problem on OCUK forums!!!
I have a new bios to test on my board at OCUK mate. Did not have time today as I was doing some profiling work for tech but its on my list.
HiThis issue may not be motherboard related as I believe the internal memory controller on the ivy bridge cpu's can vary and can require extra voltage tweaks for stability(as demonstrated above)I have noticed this myself with two different 3770K's one quite happily runs at 2400 whilst the other wont go past 2133 regardless of voltage changes.I may be wrong but both ivybridge and sandybridge specs are set 1333 (could be 1600 for IB)and anything above this is regarded as overclocking and hence chip dependant etcYou may have just been unlucky -also the higher you push the overclock and vcore the harder it is to maintain the memory speed stability.Getting a 24/7 stable overclock with ivybridge is much harder imho compared to sb.