It will depend on the individual CPU you get and the strength of it's individual MC (memory controller) many 4690's can carry 2133 and most 4790's can - but not all. That's why I was saying with the K models it wouldn't be a problem. With the non-K CPUs you mention at worse, you could drop to 1866 with tighter timings and get near 2133 performance out of either non-K.