The model Mac Pro quad core 3.2 Server Mid-2012 (Nehalem) gets it's heartbeat from a single 3.2GHz Quad Core 45-nm Xeon W3565 Nehalem processor with 256k of dedicated level 2 cache per core and 8MB of level 3 cache. BTO 'Build to Order' variants include a single 3.33GHz Six Core "Westmere" Xeon (W3680) for plus $500 over base cost, a Dual 2.4GHz Six Core "Westmere" Xeon (E5645) for plus $1075, a Dual 2.66GHz Six Core "Westmere" Xeon (X5650) for plus $2275, a Dual 2.66GHz Six Core "Westmere" Xeon (X5650) for plus $2275 and a Dual 3.06GHz Six Core "Westmere" Xeon (X5675) at plus $3475.The base factory configuration for this model is 8GB DDR3-1066 (PC3-8500) ECC SDRAM, two 7200 RPM/32MB cache 1TB 3Gb/s SATA hard drives, an 18X dual-layer "SuperDrive" plus an ATI Radeon HD 5770 graphics card running 1GB of GDDR5 RAM.
Expansion is where these models shine with 8 memory slots, each accepting up to 16GB per slot, yielding 128GB possible maximum. It also has 2 external 5.25" front bays, 4 internal 3.5" drive bays, 4 PCIe slots (2X PCIe 2.0 x16 and 2X PCIe 2.0 x4) with the video card using one slot.
Additionally these machines have 5 USB 2.0 ports, 4 Firewire 800, 2 Gigabit Ethernet, 2 Mini DisplayPorts, 1 dual-link DVI port, AirPort Extreme (802.11a/b/g/n) and Bluetooth 2.1+EDR.The Mac Pro 'Server' models typically come configured with more RAM larger hard drives and include pre-installed Apple server software.
Download the manual from here.
Learn how to install Extra RAM here.