I have Corsair Vengeance LPX 16GB (2x8GB) DDR4 DRAM 3200MHz C16 Memory Kit - White.
I've had it running at 2933mhz using the Memory Try It option in the motherboard (XMP profiles wouldn't work). The issue I have with running this speed is that if I restart, I will often get a boot loop. Sometimes it boots to the OS after 2-3 tries, the RAM is set at the right speed and all performance benchmark tools I've tried do not cause any crashes - ran stable for >1 week playing games. However sometimes it keeps boot looping, then sets the RAM back to the stock speed.
I tested again today with 2800mhz (Memory Try It), and this seems to clear up the boot loop issue. I'll probably stick with this speed for now.
Running the latest beta bios (1.71) on this mobo.