The latest version of OS X (OS X 10.10 Yosemite) is currently in beta and not available to the public yet, but you can still try it yourself without deleting your current Mac installation.
OS X Yosemite was unveiled at Apple’s WWDC developers conference in early June. However, this new version has received a major facelift in the form of an all-new UI design and a host of new features such as support for AirDrop from iPhone to Mac and the ability to send SMS text messages from iMessage on your Mac. like sending and receiving phone calls.
There are several ways to install OS X Yosemite on your Mac without risking your existing files and operating system installation. One method involves creating a second partition on your storage drive using the unused storage and installing Yosemite on the new partition. The second way is to install OS X Yosemite on a flash drive and immediately run the new operating system from the flash drive.
Which method you want to use is up to you, but the USB flash drive method may cause Yosemite to run a little slower because it runs out of USB, but if you have a fast USB 3.0 flash drive, it might not be an issue.
Here’s an overview of how to install OS X 10.10 Yosemite using any of these methods; this allows you to keep your current OS X 10.9 Mavericks installation complete and uninterrupted.
before you start
Before you start creating new partitions and the like, you’ll want to install the OS X Yosemite beta first. If you’re a registered Apple developer, all you have to do is sign in to Dev Center and you can download it from the Mac App Store here.
If you are not a developer, you can visit: this website and download the developer preview of OS X Yosemite by clicking to the right of the latest version. You will be redirected to the download site where it will take a few hours to download the .DMG file as it is about 4.5GB depending on your internet connection.
A word of warning though. At the time of this writing, this website only has Developer Preview 2 and the latest version is Developer Preview 3 which is currently not available in iMZDL except for the delta update. We tried Developer Preview 2 but it didn’t work, maybe because Apple stopped signing, but your mileage may vary. We hope Developer Preview 3 will be updated soon.
Creating a New Partition
One way to test OS X 10.10 Yosemite without breaking your main OS X installation is to create a separate partition on your Mac’s storage drive and install the beta operating system on top of it. To do this, follow these steps:
Scroll down for instructions to install OS X 10.10 Yosemite on the partition you just created.
Using a USB Flash Drive
If you don’t want to mess with partitions and risk somehow corrupting your storage drive, you can install OS X Yosemite on a USB flash drive and run from it; this is probably the safer option anyway. a spare USB drive lying around. However, we recommend that it be a USB 3.0 flash drive and your Mac supports USB 3.0, as anything slower will not run OS X Yosemite fast enough.
To install a copy of OS X 10.10 Yosemite to a USB 3.0 flash drive, follow these steps:
Installing OS X Yosemite
Installing OS X 10.10 Yosemite is actually really simple. Simply launch the installer you downloaded (it may come as a .ZIP file if you downloaded it from this website, but simply unzip it to get the installer file) and it will open a splash screen. Click , accept the terms and conditions, and then click .
Click on the drive where you want to install OS X Yosemite. This is based on the method you chose above. If you want to install Yosemite on the second partition, click on that partition. If you want to install it on your USB flash drive, select the flash drive and then click .
After the installation is complete, you will go through OS X Yosemite’s Setup Assistant to set up iCloud, iMessages, etc.
Switching Between OS X Yosemite and Your Current Operating System
If you want to revert to your current host OS, simply reboot and hold the key, then select your main hard drive from the list of drives shown. Your Mac will then boot into OS X Mavericks or whatever your current installation is.
Likewise, whenever you want to boot into Yosemite, insert your flash drive, reboot and hold and select the flash drive from the list.
