I may have missed it, but what were the memory timings for speeds other than 2133?
From those latency values, the following are the closest without going over:
1333:7-7-7-17(round up to a multiple of 3, I think) so 18
1066:6-6-6-6-14(round to 15)
800:5-5-5-11(round to 12)
Close settings that only exceed the original timings by a tiny bit:
If you left the clocks at 10-10-10-24 for all clock speeds, you're testing not just memory bandwidth, but latency tolerance as well.
Thanks for the test!