By default, the motherboard will set the RAM to run at 1600mhz. All you need to do is to go inside the BIOS and set the timings to the specified timings on the RAM (1866mhz, CAS 9, 1.5v).
Also, I just checked and the Vengeance Pro barely fits. The Noctua is only compatible with RAM that is 44mm and lower and the Pro is perfectly 44mm.