The Athlon II series is based on the AMD K10 architecture and derived from the Phenom II series. However, unlike its Phenom siblings, it does not contain any L3 Cache. There are two Athlon II dies: the dual-core Regor die with 1 MB L2 Cache per core and the four-core Propus with 512 KB per core. Regor is a native dual-core design with lower TDP and additional L2 to offset the removal of L3 cache. The three core Rana is derived from the Propus quad-core design, with one core disabled.