I don't know much about Ryzen and OC'ing it but on intel platforms I normally have to boost the DRAM voltage a little to get it stable while on XMP profiles. my 1.5v DDR3 ram in my current gaming rig I run at 1.6v. That allows me to run XMP profile and boost DRAM speed to 2133mhz and maintain stability on my Team Vulcan-1600 RAM.