does the athlon x4 880k accept 2400mhz ram

Solution
Spec is "Integrated Memory Controller Speed 2133 MHz"

It also depends on the motherboard. Faster RAM should run but will run at the slower speed.
I have an 860K and was not able to get 2400 Mhz stable without fiddling with voltages, so i just left it at 2133 Mhz. Your experience will vary and your motherboard may work better or worse than others for 2400 MHz.