And found so little difference that they stopped testing.
What you need to know is the higher MHz gives some timing space and the motherboard often can't clock to all possible values (you as the PC designer check this. not me.)
So I'm upgrading my CPU, my current one is FX-8350 and I'm getting the new i5-7600K, I have already picked out a motherboard too, which is Gigabyte GA-Z170-HD3, so now I need new RAM too and there comes my question, will RAM for X99 and 100 series motherboard work for Z170 motherboard and if yes, then which one should be better. I have three options,
3000mhz with latency of 15
2400mhz with latency of 14
2133mhz with latency of 13
The cheapest one for me is the 3000mhz variant, by 2 euros.
Here's a link to the 3000mhz RAM variant, but all the others are the same expect speed and latency. http://www.corsair.com/en/vengeance-lpx-8gb-2x4gb-ddr4-dram-3000mhz-c15-memory-kit-black-cmk8gx4m2b3000c15
Thanks in advance!