I find this mobo very weird with ram. I have some generic Kingston HyperX black that are supposed to be 10&10&10&30, but if I use XMP, it times them to CL9 and 28. I don't know why, maybe because I am running F2-bios. Memory overclocks etc. are not enabled either, the only thing I set was the volts to 1.65v. (And CPU overclock separately).
In any case, it works fine on the tighter timings, just thought I'd contribute.