Memory recommendation for Asrock Z68

[iMik]

My MB is Asrock Z68 Extreme4 Gen3, so I would like to know which one this kits is best for me.

G.SKILL Ripjaws Z series, F3-149000CL9Q-16GBZL, DDR3 1866MHz, kit 4x4GB
G.SKILL Ripjaws X series, F3-14900CL9D-8GBXL, DDR3 1866MHZ, kit 2x4GB x2
G.SKILL Ares series, F3-2133C11Q-16GAO, DDR3 2133MHz, kit 4x4GB

[Tradesman]

Some will depend on the CPU you are running - if it's a K model I'd go with the 2133 sticks

[iMik]

I have 2500K at 4.5 Ghz.

[Tradesman]

Yep, I'd go 2133

[iMik]

Thank you.

[Tradesman]

Let us know what you decide and how you like them