1866 or 1600 ram will only run at 1333 if at all2 x 1.5V DDR3 DIMM sockets supporting up to 16 GB of system memory Dual channel memory architecture, Support for DDR3 2200(OC)/1333/1066/800 MHz memory modules
1866 or 1600 ram will only run at 1333 if at all2 x 1.5V DDR3 DIMM sockets supporting up to 16 GB of system memory Dual channel memory architecture, Support for DDR3 2200(OC)/1333/1066/800 MHz memory modules