Upgrade the memory in select 2009-2012 Mac Pro systems using the 64GB DDR3 1333 MHz UDIMM Memory Kit from OWC / Other World Computing. This memory kit features a total capacity of 64GB, which is made up of eight 8GB modules. It also has a clock speed of 1333 MHz, a bus speed of PC-10600, and a 240-pin UDIMM form factor. It operates using 1.5V, has a CAS Latency of 9-9-9-24, a component configuration of 1024M x 72, a module bandwidth of 10.6 GB/s, and is equipped with ECC technology. By offering ECC (Error Checking and Correcting) technology, this RAM will help your workstation encounter fewer errors that can corrupt data sets and introduce system issues. Additionally, this memory module is compatible with Apple Specified Thermal Sensor, which ensures that the RAM maintains a safe thermal operating range.
To utilize over 32GB of memory in your Mac Pro using 10.6.x or greater, you must boot into 64-bit mode. In 32-bit mode, all installed memory will show in the system profiler, but only up to 32GB will be actively used by the computer.