Ddr3 1333mhz not working

[unubunnnn]

Hello there. I'm using 2 ram kits with 2 gigs each, 1333mhz each, CL9 each. If I leave the jumpers by default I only get 400mhz - I want to use them at their full potential so I changed the jumpers as I saw in the manual (I'm using a http://www.asrock.com/mb/Intel/X48TurboTwins/ ). I placed them as shown for the 1333mhz situation but now I only get like 319 MHz (ddr 667 or smth..). Does anyone have any idea how can I fix this? Thanks!

 

[algorithmbreaker]

First try one 2 GB DDR3 1333 MHz in the first slot in default jumper position, then check the frequency it is running in. Then try only one pair in the Green Slot (A1, B1), check frequency. Then you can move to four slot population and change jumper if necessary.

 

[unubunnnn]

Well thanks for your answer but I figured it out. It's because of my cpu (core 2 duo e6600). My cpu supports 1066max