Full Details from Amazon.com : http://www.amazon.com/gp/product/B00JIJUAHM?tag=onigi-20Transcend 8 GB DDR3-1866 ECC Registered DIMM 2Rx8 TS8GJMA335H (Mac Pro Late 2013 Compatible)Registered DIMM 512Mx8 bit 1866Mbps 15V Timing 13-13-13 2 Ranks