know which the single 6-core chip is? it's at 3.33 GHz, if that helps. From the Apple Store , the 4-core is a W3565 ( Bloomfield Nehalem, launch date Q4 2009) upgradable to a 6-core W3680 ( Gulftown Westmere, Q1 2010). The 12-core is a pair of E5645 ( Gulftown Westmere,