Boost your supported Mac Pro's performance with the 128GB DDR4 2666 MHz R-DIMM Memory Upgrade Kit from OWC / Other World Computing. Delivering speeds up to 2666 MHz, this 4 x 32GB kit is a memory upgrade designed to improve your computer's start-up times, overall responsiveness, and ability to handle data-intensive applications. ECC (Error-correcting code) technology enables the modules to detect and correct the most common kinds of internal data corruption. The modules are registered, feature a CAS latency of 19 and a power rating of 1.2V, and work on systems with 288-pin DIMM slots and a DDR4-enabled chip.
Note: Do not mix R-DIMMs and LR-DIMMs. Mixing R-DIMMs and LR-DIMMs will result in a memory error flash of the status indicator light when you turn on the Mac Pro.