My ram is not clocked at 1600mhz?

[745i]

Ram : Corsair Vengeance 16gb at 1600mhz (4x4gb)
Motherboard: ASUS P8Z77-V
On CPU-Z it shows dram frequency is around 668.7 mhz, so is it normal or what do I do to make it normally 1600 mhz on the Asus p8z77-v?

 

[Tradesman1]

That's showing you are running roughly at 1333, go into BIOS, enable XMP and select profile 1, should be at 1600 then (will show 800 (true freq) in CPU_Z (take that times 2, as is DOUBLE data rate, to get the 1600 effective)

 

[smorizio]

in advance mode under the ai tab there a line that says dram speed (auto). click on it set it to xmp profile one and save it and exit.

 

[SchizTech]

That frequency you see is doubled to determine the full data rate; that is, 668 mhz = DDR3-1333.

What CPU are you using? Go into the BIOS and enable XMP, which should run the RAM at 1600