I cant clock memory to its original speed.

[LoneWalkerXD]

I have kingston hyper x fury 2666mhz cl16 8gb sticks. Ive added second stick just today. İn the bios it shows 2666mhz but in cpu-z, task manager also aida64 it shows 1333mhz. I dont understand the double data rate, before second stick I can see my ram speed as its max on task manager and cpu-z. Tried both A-xmp profiles also s et clock speed to 2666mhz myself. 

[Aimi]

1333 x 2 = 2666mhz

[minibois]

3 minutes ago, LoneWalkerXD said:

I have kingston hyper x fury 2666mhz cl16 8gb sticks. Ive added second stick just today. İn the bios it shows 2666mhz but in cpu-z, task manager also aida64 it shows 1333mhz. I dont understand the double data rate, before second stick I can see my ram speed as its max on task manager and cpu-z. Tried both A-xmp profiles also s et clock speed to 2666mhz myself. 

Long story short: your memory is running at the right speed, if CPU-Z shows 1333Mhz.
 

Long story a bit less short:

Your memory runs at 1333Mhz, which is (millions) of ticks per second. Per tick it can do two transfers (which is why it is called DDR = Double Data Rate), so it is running at 2666MT/s (millions of transfers per second). Manufacturers of memory/motherboards call this 'MT/s' unit 'Mhz', thus 2666Mhz.

CPU-Z reads it out the right way, thus 1333Mhz.