Mid-2012 - MacPro5,1 (12-core)
Compatible upgrades for: MD771LL/A Mid 2012 Twelve core Mac Pro's.
Standard RAM: 12 GB
Maximum RAM: 128 GB*
Details: By default, 12 GB of RAM is installed as six 2 GB modules. Two slots free.
*Apple officially supports 64 GB of RAM in this model, but it actually can support 96 GB running Mac OS X 10.6 or 10.7, and up to 128 GB, but only when running a 64-bit version of Windows XP or later or Linux. Mac OS X only can support 96 GB of RAM.
RAM Slots: 8*