[SOLVED] Can i put different RAM with different speed?

Solution
Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
The internal workings are designed for the capacity of the kit.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards, can be very sensitive to this.
This is more difficult when more sticks are involved.

I have doubts that your plan would work.
All ram must be managed in the same manner by the motherboard.
I do not think you can overclock just one pair of sticks.

If you do manage to get things to work, they will operate at 1333.
That is not all bad.
Intel ram controllers are very good at anticipating ram need so actual performance is not much...
Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
The internal workings are designed for the capacity of the kit.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards, can be very sensitive to this.
This is more difficult when more sticks are involved.

I have doubts that your plan would work.
All ram must be managed in the same manner by the motherboard.
I do not think you can overclock just one pair of sticks.

If you do manage to get things to work, they will operate at 1333.
That is not all bad.
Intel ram controllers are very good at anticipating ram need so actual performance is not much impacted by ram speed. If you are using integrated graphics, the impact of slow speed ram is higher.

If you want 32gb, buy a 4 x 8gb ram kit that is supported.
Your motherboard has picky requirements. The 8gb sticks must be of the 16 cell type.
Best to use the ram QVL list ti identify a supported kit.
https://www.asrock.com/mb/Intel/Z77 Extreme6/#Memory

Keep your old ram as backup or sell it.
 
Solution