2400 , and moreover, 2133 is plain silly to buy DDR4. Even 2666, you can just purchase a solid ddr3 for that matter.
3000 on the other hand, although we have tons of ddr3 that come even stock at 3000mhz, looks tastier. Until I see DDR4 over 3000 and with reasonable price, I'll refrain from it.
So I should skip Haswell refresh if I have 4770k ,maximus VI impact and 2400mhz ram, right?
