July 2010 -Nov 2013
Original OS 10.6.4
Processor: Intel Xeon 'Nehalem' or 'Westmere'
CPU:
Quad-Core
1 x 2.8 GHz Nehalem (1066 MHz RAM bus)
1 x 3.2 GHz Nehalem (1066 MHz RAM bus)
Single 6-Core
1 x 3.33 GHz Westmere - 6 core **(1333MHz RAM bus)
8-Core
2 x 2.4 GHz Westmere (1066MHz RAM bus)
12-Core
2 x 2.66 GHz Westmere - 12 core **(1333MHz RAM bus)
2 x 2.93 GHz Westmere - 12 core **(1333MHz RAM bus)
2 x 3.06 GHz Westmere - 12 core **(1333MHz RAM bus)
RAM slots: 4 with Single Processor - 8 with Dual Processor
Maximum RAM in OSX - 64 GB Single Processor - 96 GB Dual Processor
RAM type: 240 pin PC3-8500 DDR3 1066 MHz ECC SDRAM (4 and 8 Core)
** 240 pin PC3-10600 DDR3 1333 MHz ECC SDRAM (6 and 12 core)
MacPro5,1 will boot natively into a 64 bit kernel and can boot 32 bit.