You’ll also want to make sure you have at least 2GB of RAM and a minimum of 8 – 10GB of free space on your hard drive. There are some reports of users modifying a system file that tells the OS whether it’s on supported hardware, and getting machines like the powerful 2008 Xserve servers up and running : but it’s not for the faint of heart, since you run the risk of losing the ability to boot any time your software gets updated.
Luckily, Apple posts a handy list of the models you can expect to be compatible with the new OS:
Some older Macs will also be upgradeable, but you’ll need to check in order to make sure. That means that if your Mac runs OS X 10.10 “Yosemite”, 10.9 “Mavericks”, or 10.8 “Mountain Lion,” it’ll run El Capitan.
This is the window that pops up when you click on ‘About This Mac.’
