Since Apple computers often have very specific memory requirements, including particular component densities, speeds, and SPD programming specifications, it's important to use a memory that's engineered for your Mac. With more than a decade of experience manufacturing and developing memory for all types of Apple computers, trust Crucial memory to optimize your Mac system's performance. When you use your Mac system, you expect intuitive, dependable performance. And if you're a Mac Pro user, you expect mission-critical workstation reliability. Expect the same out of your memory. Every module that leaves Crucial's doors has been extensively tested at the component level for voltage and temperature resistances, signal integrity, and software compatibility. Our modules are lead- and halogen-free. A memory upgrade is the fastest, easiest, and most affordable way to get more performance out of your Mac system. Standard DDR3 modules help Mac systems reach speeds up to 1600 MT/s. For newer Mac systems, DDR3L modules are available. These modules deliver speeds starting at 1866 MT/s and use 10% less power for improved energy efficiency.