Why is my G.Skill 6400 800MHZ only showing at 400MHZ in

[Malazan]

CPU-Z?

The timings look right on the tab 5-5-5-15 (it's CAS 5), but why the low rate? it also shows timings for 266MHZ.

 

[Malazan]

So my RAM is actually running at the correct speed, not half speed as it appears?