What CPU? That will be the determining factor. The DRAM is rated to 1600 so it 's not being OCed....the (OC) indicates it may take an OC of the CPU (more specifically - the CPUs MC (memory controller)) to run at full 1600. i.e. the AMD 965 was the first of their CPUs to reliably run 1600 DRAM, if a 955 or lower may have to drop to 1333 or lower