Nice testing, however my only gripe are the actual timings you used.

When people talk about memory timings they usually talk about the differences between 2-2, 3-3, and 4-4 timings. You tested by only changing the CL rating which has a very minimal impact on performance.

Can you test with different timings? (ex 2.5-3-3-7, 3-4-4-8, this is where you will see how much timings matter)