I couldn't even get 2133 11-11-11-28-1T at 1.5 or 1.55.
Try changing the command rate to 2T, it barely affects performance. Now I'm running 2133 9-10-10-21-2T @ 1.55. I was stable for about 15 mins Prime95 Blend at 1.475, but to get complete stability I needed 1.55.
CPU-Z and MaxxMem both say it's running at 1T but it's actually 2T.