Used - fully tested. This AMD Athlon II X4 651K CPU features four cores and a clock speed of 3.0 GHz, This is a Black Edition CPU making it a powerful addition if you are focusing on overclocking. The socket type is FM1 and the processor model is AMD Athlon II X4 651. It has a L2 cache of 4x1 MB, making it efficient for multitasking. This processor is compatible with various motherboards and is ideal for gaming and other resource-intensive applications.