Welp the 4000 kit i bought i could only get "stable" at 2933. I say "stable" because while i never crashed i would keep getting whea errors no matter what i did. I upped SOC voltage, ram voltage, cpu core voltage and kept getting errors. Sending it back and just sticking with my el cheapo ram til either bios gets fixed, or i go back to intel lol. (ram i have is on most z270 boards QVL list)
Whats more disappointing is my FPS were identical with 2933 cas 14 ram as 2400 cas 15, i only tested wow overwatch and swtor, but the numbers didnt change one bit.