Mac Pro is the fastest, most powerful Mac ever. Its Intel Xeon processors increase performance up to 1.5x,1 and advanced graphics processors are up to 5x faster. It can even be configured with up to 12 processor cores.2 You can add up to 32GB of memory, four PCI Express expansion cards, and up to 8TB of hard drive storage.3 And now Mac Pro comes standard with OS X Lion, the latest release of the world's most advanced desktop operating system.