Looking for a way to install and run OS X on an external hard drive? This can be useful for a couple of different reasons. Firstly, it allows you to run another copy of OS X without needing any additional Mac computer.
Mac Snow Leopard offers an application called the Activity Monitor, which is designed to show you just how hard your CPU, hard drives, network equipment, and memory modules are working behind the scenes. To run Activity Monitor, open the Utilities folder in your Applications folder. To display each different type of usage, click the buttons. When you do that, you should see at least four icons. In my case, I have five because I have Windows installed using Boot Camp. Anyway, the grey MacBook and Recovery 10.11.2 icons are for my internal OS X and the orange OS X and Recovery 10.11.3 are for the version installed on my external drive. Use the arrow keys to select which drive to boot from and then simply press Enter.
Also, since you can run a full copy of OS X on the external drive, it can be used for troubleshooting purposes on other Macs or it can be as a kind of virtual OS X. I’ve already written about how you can install OS X in VMware Fusion, but that takes up space on your Mac. Using an external drive, you can save space on your Mac, though it might be a bit slower if you are using USB 2.0.
In this article, I’ll walk you through the requirements and steps to install OS X onto an external hard drive.
Format External Hard Disk
The first thing you’re going to need to do is format the external hard drive properly. The file format has to be Mac OS X Journaled and you have to use the GUID partition map. To do this, open Disk Utility and connect the drive to your Mac.
Under External in the left hand menu, click on your external hard drive and then click on the Erase button. Make sure you backup any data before you erase the drive. When you click Erase, a dialog will pop up where you can configure some options.
Give your drive a name, choose OS X Extended (Journaled) for Format and GUID Partition Map for Scheme. It should only take a minute or two for the drive to be erased and reformatted. Now your drive is ready for OS X.
Install OS X
There are two ways you can install OS X on to your external hard disk: by reinstalling OS X from the OS X Utilities repair screen or by downloading OS X from the App Store and running the installer. I’ll show you both methods in case one isn’t working for you.
The easiest way is to download OS X from the App Store. Once you open the App Store, you’ll see a link on the right for the latest version of OS X (El Capitan as of this writing).
Go ahead and click the Download button to start downloading the installer. Note that if you already have that version of OS X installed, you’ll see a popup message appear asking if you still want to continue or not. Just click Continue.
Once it has been downloaded, just double-click the installer, which will be located in the Applications folder.
Keep clicking past the license agreement, etc., until you get to the screen that asks you which disk to install OS X on. By default, it is set to MacBook.
Click on the Show All Disks button and you’ll see an icon for the different disks and partitions on the Mac. I named my external hard drive OS X and that shows up in the middle.
You can also tell it’s an external hard disk because it uses the icon with the orange hard drive. Click Continue and then follow the instructions to complete the installation. Note that your computer may restart during the install and you don’t have to do anything. OS X will automatically continue installing onto the external hard drive rather than booting up to your internal version of OS X.
At the end of this article, I’ll show you how to boot up to the external hard drive, so skip down if you ended up using the App Store method. Note that by default, the Mac will start booting up directly to the external hard drive until you change it.
The second method to install OS X is to restart the Mac and press and hold the COMMAND + R keys. This will load up OS X Recovery.
The OS X Utilities screen will appear and here you want to click on Reinstall OS X. Again, you’ll go through some basic screens, but when you get to the hard disk screen, click on Show All Disks again.
Using this method, you’ll have to login using your Apple ID and password so that the entire OS X installer can be downloaded off of Apple’s servers. Whichever method you choose, it will take anywhere from 15 to 30+ minutes to install OS X onto your external hard drive.
While OS X is installing, your computer will restart a couple of times. Note that when it finally boots into OS X, that is the version running off your external drive. To switch back and forth between the internal and external drive, you have to restart your computer and hold down the OPTION key.
When you do that, you should see at least four icons. In my case, I have five because I have Windows installed using Boot Camp. Anyway, the grey MacBook and Recovery 10.11.2 icons are for my internal OS X and the orange OS X and Recovery 10.11.3 are for the version installed on my external drive.
Use the arrow keys to select which drive to boot from and then simply press Enter. If you have a newer Mac and a USB drive that supports USB 3.0, everything should run fairly fast. Overall, it’s a fairly straight-forward process and took me less than an hour to get everything working. If you have any questions, feel free to comment. Enjoy!
Mac Snow Leopard offers an application called the Activity Monitor, which is designed to show you just how hard your CPU, hard drives, network equipment, and memory modules are working behind the scenes. To run Activity Monitor, open the Utilities folder in your Applications folder.
To display each different type of usage, click the buttons in the lower half of the window; the lower pane changes to reflect the desired type. For example, if you click System Memory, you see the amount of unused memory; click CPU or Network to display real-time usage of your Mac’s CPU and network connections.
Mac Os Hard Drive Speed Test
Mac Os Hard Drive Space
You can also display a separate window with your CPU usage; choose Window→CPU Usage or press Command+2. There are three different types of central processing unit (CPU, which is commonly called the “brain” of your Macintosh) displays available from Activity Monitor:
Floating CPU window: This is the smallest display of CPU usage; the higher the CPU usage, the higher the reading on the monitor. You can arrange the floating window in horizontal or vertical mode from the Window menu.
CPU Usage window: This is the standard CPU monitoring window, which uses a blue thermometer-like display. The display works the same as the floating window.
CPU History window: This scrolling display uses different colors to help indicate the percentage of CPU time being used by your applications (green) and what percentage is being used by Snow Leopard to keep things running (red). You can use the History window to view CPU usage over time.
Do you have two (or more) bars in your CPU usage monitor? That’s because you’re running one of Apple’s multiple-core Intel processors. More than one engine is under the hood!
Mac Os Hard Drive Icon
Whichever type of display you choose, you can drag the window anywhere that you like on your Mac OS X Desktop. Use the real-time feedback to determine how well your system CPU is performing when you’re running applications or performing tasks in Mac OS X. If this meter stays peaked for long periods of time while you’re using a range of applications, your processor(s) are running at full capacity.
You can even monitor CPU, network, hard drive, or memory usage right from the Dock! Choose View→Dock Icon; then choose what type of real-time graph you want to display in your Dock. When you’re monitoring CPU usage from the Dock, the green portion of the bar indicates the amount of processor time used by application software, and the red portion of the bar indicates the CPU time given to the Mac OS X operating system.
Mac Os Benchmark
Note, however, that seeing your CPU capacity at its max doesn’t necessarily mean that you need a faster CPU or a new computer.