Install the El Capitan beta on that drive and boot from it whenever you want to test El Capitan. If you have problems with the beta OS, at least they won’t affect your “production” Mac.

Install El Capitan (Image credit: Future) A big cat's roar from DiskMaker X signals that your OS X boot disk is ready – you should see it on your desktop named 'OS X Install ESD'.

Installing OS X 10.11 El Capitan Once the update goes live, download times are likely to be long as users around the world look to upgrade their systems all at once.

OS X El Capitan takes the legacy of Yosemite's features to a new level. It's easy to enjoy the new OS for Mac: all you need is a compatible computer, 8GB flash drive and directions on how to install.

Reasons to install OS X El Capitan and reasons not to install. We’ve heard from users who bought new Macs in 2016 and found them running OS X Yosemite, which brought them to this decision.

After El Capitan downloads, you will need to choose where to install it. If you created a partition, click Show All Disks from the installer window and select your partition before clicking Install.

The developer beta of OS X El Capitan has been available since WWDC in June, but to get it you needed to sign up for one of Apple's $99-a-year developer accounts.

As expected, OS X El Capitan has been released and can be downloaded right now from the Mac App Store. Here’s how to perform a clean install of OS X El Capitan.