64GB (2x32GB) DDR3 ECC Registered CL9 PC3-10600 1333MHz SDRAM Memory RAM Upgrade Module Compatible with All 2013 Mac Pro 6,1 Models

Product Specs: Size: 32GB (32768MB) | 240-pin SDRAM DIMM | 2048M x 72, Quad Rank ECC Memory Module | Module Bandwidth 10.6GB/s | Data Rate= 1333MHz | CAS 9-9-9-24 | Voltage 1.5V  | Apple Specified Thermal Sensor | RoHS Certified | Warranty Safe Upgrade. | OWC Memory Lifetime Limited Warranty including Advanced Replacement Program | OWC Memory For Mac Pro 2013 fully meets Apple's specifications with special attention to proper thermal specifications. IMPORTANT OWC NOTE: Apple Mac Pro 2013 models utilizes ECC non-Registered for 4GB and 8GB per slot options and ECC Registered for 16GB (and larger) per slot options. Any existing 4GB and 8GB ECC non-Registered modules cannot be mixed with 16GB and larger ECC-Registered modules and will need to be removed in order to utilize these higher density memory upgrade options. Special 32GB module use information: Due to processor design and memory architectures, 32GB module utilization occurs at a bus speed of 1066MHz with Apple Mac Pro 2013 E5-16XXv2 4-Core, 6-Core, and 8-Core processor equipped models, 800MHz with factory 12-Core or after-market E5-26XX equipped models. Utilization of 2 or more 32GB modules minimum is recommended and utilization of overall performance with applications and workflows able to utilize higher available memory remains exceptional.