Get your Mac ready for Lion | Operating Systems | MacUser | Macworld: To install Lion, you need a Mac with a minimum of 2GB of RAM and one of the following Intel processors: Intel Core 2 Duo, i3, i5, i7, or Xeon—early Intel-based Macs with Core Solo or Core Duo processors aren’t eligible. You can determine your Mac's processor and the amount of installed RAM by choosing About This Mac from the Apple menu and looking at the Processor and Memory lines, respectively.