32GB OWC Mac Pro Late 2013 Quadruple Channel Kit PC3-14900 1866MHz DDR3 ECC-R SDRAM (4x 8GB) by OWC

At OWC, we want your Mac to perform faster and last longer. That’s why we engineer memory specifically tested and optimized for Mac. There’s OWC memory for nearly every upgradeable Mac, from the PowerMac G4 to the latest 2017 iMacs. Plus we make it easy to upgrade by yourself with step-by-step install videos, and included toolkits. It’s the easiest way to improve your Mac’s performance.

Compatible with:

Mac Pro
(December, 2013) 
Model ID: MacPro6,1
2.7GHz 3.0GHz, 3.5GHz, 3.7GHz

OWC Memory for Mac Pro 2013 fully meets Apple's specifications with special attention to proper thermal specifications.
IMPORTANT MAC PRO 2013 UPGRADE NOTE:
Apple Mac Pro 2013 models utilize thermal enabled ECC-Registered and ECC non-Registered memory. ECC Registered and non-Registered memory may not be mixed. Existing factory or post installed 4GB or 8GB ECC non-Registered modules need to be removed prior to installation of OWC 8GB, 16GB, or 32GB server grade ECC-Registered memory upgrades.