Crucial 8GB Single DDR3 1866 MT/s (PC3-14900) EUDIMM 240-Pin Memory For Mac Pro Systems (Late 2013) CT8G3W186DM Compatible Upgrade for Apple Mac Pro (Late 2013 model) Increases system performance. Runs at 1866MHz. ECC Registered DDR3 Installation of 16GB modules requires all previous lower density modules to be removed You cannot mix Registered and Unbuffered memory in the same system Easy to install. Limited lifetime warranty. Trusted by enthusiasts of Mac systems