2400Mhz 16GB x 2

Hello



I purchased 2 packs of CMY16GX3M2A2400C11R thinking I would be able to combine them easily.(32GB)



After some researching I hear its not advised to do this?



I installed these in my PC, which is built with



4770k

Asus Maximus VI Extreme



When I turn on the PC, my ram reading is showing only 1333Mhz at 32GB in the bios.

I have tried to change the "memory frequency" section to 2400Mhz, but on boot it responds.



"memory overclocking failed, press f1 to...."



I also readI should perhaps change the timings if I am going to change frequency, but I do not know what the timings should be.



I also tried selecting XMP profile, but again on boot it responds the same message.



"memory overclocking failed, press f1 to...."



Can anybody help?



Thanks