Memory RAM not at correct speed

Noticed this since I build the rig around a week or two ago. I have 8GB (2GB x 4 kit) of corsair DDR3 that should be 1600, but it was running at 665. Went into the BIOS today and enabled to profile1 already saved, the BIOS then showed it at 1600 (the speed it should be) but when I used CPU-Z just now it states it is running at 798hz

RAM is Corsair Memory XMS3 Classic 4GB DDR3 1600 MHz CAS 9-9-9-24, 1.5V
I5 2500k
Mobo is Gigabyte GA-P67A UD4 B3

Any help on how to get it to run at 1600?

 

When you look at CPU Z it is actually double that speed as it is running in dual channel mode

798x2 = 1596 (fail prolly)

 

Nothing to do with dual channel; DDR = double data rate.

 

I didn't expect that to be so profound. Why can't motherboards just report the expected speed.

 

oh man I feel like an idiot now ... LOL.

Thank you!

 

I stand corrected

 

some do some dont completely up to to the mobo manufacturer

 

DDR means the RAM triggers on the rising and falling edge of the clock. The clock frequency stays the same, but the RAM acts like there have been 2 clock ticks for every single tick effectively doubling the clock.