I'm running a ryzen 7 1700x on asrock's x370 Pro4 mobo, and 16gb of Ripjaws V 3000mhz rated ram, but even on the latest bios the most I can manually OC to is 2733. If I don't apply OC (using Xmp) it runs at 2133
Edit: symptoms of anything above 2733:
The computer boots fine until past the splash screen from which you can get to bios, but then the screen freezes
@3000mhz the computer reboots 3 times and starts up in 2133mhz mode