It may 'work', though at a lower freq, the Athlon II CPUs are rated up to 1333 (with 2 sticks and if it's an X3 or X4 model, the X2 Athlons are rated up to 1066), it's more the CPU, specifically the MC (memory controller) of the CPU that determines what freq DRAM you can run the 965 rev C3 was the first AMD CPU that could reliably run 1600 sticks