I would dial down the CPU, shoot for low temps, base speed. I know this CPU will throttle and not show a frequency drop when doing a negative Vcore. I'm not saying that is for sure the issue, but best to eliminate that variable. Verify that you get the results you expect and go from there. Also, try different interleaving sizes with each speed, it can be a detriment for higher speed higher latency ram to be using a tiny interleave size.