The easiest way to start enjoying OS X Mountain Lion is to buy a new Mac—the operating system is preinstalled, and you get a brand-new computer to boot! If you’re one of the lucky ones getting a new Mac, you likely want to learn how to get all your important data from your old machine to the new one; see Moving Data and Applications for details.
However, you don’t have to buy a new Mac to run Mountain Lion, and since transferring your data is a little time consuming, you might not want to. If your Mac meets Mountain Lion’s requirements (explained next), you can simply upgrade your old Mac to Apple’s latest and greatest. This chapter gives you the lowdown.
With every revision of OS X, Apple leaves some Macs behind, and Mountain Lion is no exception. To install Mountain Lion, your Mac has to possess a 64-bit Intel Core 2 Duo processor or better, be able to boot into the OS X 64-bit kernel, and have an advanced GPU (graphical processing unit). But those kinds of requirements are hard to commit to memory—ask 100 Mac users what GPU chipset their machine employs, and the vast majority of them will give you a puzzled look (the people who do know the answer are hard-core types and should be left alone).
So how do you find out whether your Mac is compatible with Mountain Lion? The simplest way is to try to buy the software from the App Store. If your Mac isn’t compatible, the App Store will tell you that ...