That was me, and here's the link to look at the DRAM QVL list, which has over 20 sets listed at 3000 and above,
https://www.asus.com/us/Motherboards/SABERTOOTH_X99/HelpDesk_QVL/
I also explained why the advertise the lower, it's in keeping with the all the previous Sabertooth mobos that typically list 1866 as the top in the open advertising.