The 64-bit 22-nm "Xeon E5" processor, or more specifically the "Ivy Bridge-EP" based E5-1680v2, has eight independent "cores" each with a dedicated 256k level 2 cache and 25 MB of level 3 "Smart Cache." It also supports "Hyper-Threading" which "allows two threads to run simultaneously on each core" (so OS X recognizes sixteen total cores on this model, eight real and eight virtual) and "Turbo Boost" which "automatically boosts the processor speed based on workload" up to 3.9 GHz for this model.