Before upgrading to El Capitan it is wise to try it on external drive or install it on another partition along side your existing OS X (dual boot). But if you have an extra external drive or an empty one you can try installing Mac OS X 10.11 El Capitan on it and check out its new features.
There is only one prerequisite i.e high speed external hard drive. So either you should have external hard drive with thunderbolt or atleast hard disk with USB 3.0. If you are using USB 2.0 Hard disk, the performance will be horrible since the I/O operations will be at much slower rate.
I have Macbook Pro 13 retina with 8GB RAM, i5 processor and 1TB Seagate external drive with USB 3.0 which when I tested and it I got around 150 MB/sec transfer speed. Now lets see step by step installation process.
Step 1: Format external hard drive
- Plugin your external hard drive
- From applications launch “Disk Utility”
- Select your hard drive in the disk utility app.
- Select “Partition”
- In the “Partition Layout”, you should select “1 Partition” or at max “2Partition”. I had choosen 1 partition.
- Give name to your partition eg. “OS X El Capitan”.
- The partition format should be “Mac OS Extended (Journaled).
- Now click on “Options…” and select “GUID Partition Table” and then click on “OK”.
- Finally click on “Apply” to format and partition your external hard drive.
Step 2: Download Mac OS X El Capitan 10.11
- Go to https://beta.apple.com/ and Sign In if you already signed up or else sign up using your AppleId and password.
- Go to the section where you see “Enroll your Mac”, and click on the link “enroll your Mac” there.
- Now when you click on “Download the OS X El Capitan Public Beta” button, the download process will be launched in “App Store”. File size is around 6 GB.
Step 3: Install Mac OS X El Capitan / OS X 10.11
- From Applications, launch “Install OS X El Capitan”.
- As you proceed with the installation, you will be prompted to take backup of your data. Since we are installing it on external drive, you can continue with the installation.
- Click on “Show All Disks…” button, so that you can select the disk where you want install El Capitan.
- Choose the disk where you want to install the OS X El Capitan.
- Click on Install to start the installation process. Your Mac will restart automatically and you will go through the installation process.