N00b ram question...1600, 2133, 2666?

[funsoul]

Hi Folks

Likely an exceptionally newb question but....for benching...I've been ASSuming that it's always best to go with the fastest ram possible (am not sure if that's really true but that's what I'm thinking). Is that actually true?

For example...been trying to bench an A10-6800k in an asrock fm2a75 pro4-m (before jiccman1965 dishes me a beating). Atm...am using 2x4gb of 2666mhz 11-13-13 1.65v TridentX. The board is supposed to be able to run at 2600. Would I be better off using something else (have some nice 2133 sticks)?

How about in the x48 REX? Been running corsair dominator 1600's (which have run around 2100 speed). What would be the best ram for that one?

What about a RIVE?

tia for any clarification and/or guidance!

 

[JLK03F150]

I'm new to DDR3 but from what I've been reading, higher RAM frequencies limit your max stable CPU frequency because of the IMC. It's supposed to be best to max the CPU, then increase the RAM until it makes the CPU unstable, then back down the RAM a tick. CPU is just about always most important in benching.

The REX is a whole different thing though since it still has a NB. I'm guessing timings combined with frequency matter. What are the timings at 1600 vs those at 2100? Loosening too much to get higher frequency can be harmful in benching sometimes.