Tuneup Your OS X Mac – Hardware Upgrades

I have written other articles about how you can “Tuneup” your Mac to make it run a little more efficiently. This article will focus on the ultimate “Tuneup” for your Mac – upgrading the memory and boot disk (the disk that you are running OS X from).

Now, I have to preface this article by saying that not all Macs can be upgraded. Some, particularly the latest Macs, have soldered-in components that do not allow for upgrades. To find out if your Mac can be upgraded you can look up your particular Mac model at the OWC web site, or visit this page strictly targeting memory upgrades.

The Problem

I started out the Tuneup series saying that my Mac Mini has seemed to be running slow. I have applied the many tweaks I have outlined in the other articles of the series, but I finally made the decision to make the ultimate upgrade – expanding the system memory and replacing the boot drive with an SSD.

My Mac Mini originally had 4GB of RAM, which worked OK as long as I did not have too many Apps open. I have also needed to do something about my original 500GB disk drive. As I mentioned in the first article of this series “Tuneup Your OS X Mac – Part 1“, maintaining a minimum of %10 free space on the boot drive is desired for optimum performance. This has required that I repeatedly remove files to get the free space I needed. The disk is also at the low end of the performance scale, running only at 5400 rpms. As I discussed in my “Mac OS X – Adding an External Disk Drive” article, the faster the disk access time, the faster the system performs. A disk running at 5400 rpms does not have fast access.

Upgrading the Memory

I ordered 8GB of memory from OWC and, following the provided instructions, quickly opened up my Mac, removed the old memory DIMMs and replaced them with the new 8GB DIMMs. I closed up my Mac and rebooted it. Rebooting took a fraction longer, most likely for the additional time required for POST to run with twice the memory.

Operation after the upgrade was remarkably faster. All applications seemed snappier, and the system did not slow down once I had a dozen or so tabs open in Safari. I was also able to open more Apps simultaneously without the system slowing down. I ran with my system like that for most of a week and felt very satisfied that adding RAM made a huge improvement.

Adding the SSD Hardware

This past Saturday I undertook the task of opening up my Mac Mini and adding a second disk, a 60GB SSD I had purchased from OWC. The first thing I did was to run Time Machine to make sure that I had
an up-to-date backup of my system.

The process of installing the SSD was a little more complicated than simply upgrading the memory, as the Mac Mini had to be disassembled down to the primary components. The printed instructions that accompanied the SSD from OWC provided detailed, step-by-step directions with pictures of each step. Disassembly, installation and reassembly took a little over an hour.

I did find that the Airport Antenna did not fit back into place as it should due to the SATA control cable from the SSD preventing the original disk drive from seating fully into place (a topic I plan to follow up on with OWC Support), but the components were all held into place and the bottom cover easily went back onto the Mac Mini.

Configuring the System for Two Drives

I rebooted, and the new drive showed up. I then used Disk Utilities (Go >> Utilities >> Disk Utility) to format (Mac OS Extended (Journaled)) the new drive. I first tried to manually drag and drop all but the ‘User‘ folder from the old disk to the SSD to make it bootable. The files appeared to all copy over, but the system failed to boot from the SSD.

I fixed the issue by downloading the App Carbon Copy Cloner (CCC) and configuring it to copy all but the ‘User‘ folder over to the SSD. CCC was smart enough to check what was already in place and just copy over those files that were missing. In my case, this was about 3.87GB of additional files. When that was done I tried booting from the SSD again and it went smoothly. On my desktop I saw two disks, the new SSD boot drive ‘Mac OS X‘ and the old disk ‘Macintosh HD‘.

Tuneup Your OS X Mac - Hardware UpgradesNow that I had the SSD configured as the boot drive, I configured my user account (Apple >> System Preferences >> Users & Groups >> unlocked the panel so I could make changes >> Control-clicked on my account >> Advanced Options) to use the old disk for my user ‘Home‘ directory. I clicked on the ‘Choose’ button for the ‘Home directory’ field and then picked the ‘Home’ directory for my user from the folders on the original disk.

Rebooting, my account had all of the information from the old disk in the ‘Home’ directory. All worked well, but as I continued to use my system I found that some of the normal folders listed in the Finder window were pointing to the empty ‘Home’ directory on the SSD instead of the ‘Home’ directory on the old disk like I wanted.

To remedy this I used a little “Unix magic” learned from my 20 years of Unix/Linux System Administration work and resorted to a Command Line Interface (CLI) fix. I opened a terminal (Go >> Utilities >> Terminal) and entered the following command:

/Volumes/Mac OS X/Users/jpurvis

The ‘pwd‘ command displays the path to the current working directory, in this case the ‘Home’ folder for my user account. Unfortunately, that path is for the newly created folder on the SSD that I just installed. My user data was on the old drive. I didn’t want to have to fix the problem in detail, so I replaced the ”Users‘ folder on the SSD with a symbolic link to the ‘Users‘ folder on the old drive. In the terminal window I entered the following commands:

cd .. /..
sudo mv Users Users.bak
sudo ln -s /Volumes/Macintosh\ HD/Users  Users
sudo chgrp wheel Users
ls -l Users
lrwxr-xr-x  1 root  wheel  27 Feb 23 16:42 Users -> /Volumes/Macintosh HD/Users

What did these CLI commands do? The ‘cd ../..‘ moves up two levels in the directory structure to the ‘/Volumes/Mac OS X‘ folder. Then the ‘sudo mv Users Users.bak‘ temporarily invokes root or superuser privileges to rename the folder ‘Users‘ on the SSD to ‘Users.bak‘. I used the command ‘sudo ln -s /Volumes/Macintosh\ HD/Users  Users‘, again with root privileges, to create a symbolic link to ‘/Volumes/Macintosh\ HD/Users‘ on the old disk. This done there is now what looks like a directory ‘Users‘ on the SSD, but in reality any references to it are redirected to the ‘User‘ directory on the old drive. With ‘sudo chgrp wheel Users’ I updated the ‘group’ ownership of the folder to ‘wheel’ to match that of the original ‘Users‘ folder. The ls -l Users‘ simply confirms that the link is in place with the correct ownership.

I should note that every time you use ‘sudo‘ you will be prompted to enter the user password. This command lets a normal user run a command as the root user. This feature is built into OS X to allow users to perform various administrative tasks. BE CAREFUL running commands as the root user!!!! You can easily render the system inoperable if you do not know what you are doing. 

I rebooted and now with the symbolic link in place, everything worked as it should.


I think that the results were spectacular. Everything worked much
faster. Apps take a fraction of the time to start up.

I had run a very simple measurement prior to the upgrade to give me some measurement of improvement. I manually measured the time it took the system to boot up and present the login screen. This isn’t a very deep test, but it gives a quantitative indicator of what the upgrade to an SSD provides. I ran that test after the new memory was installed and after the SSD had been installed. The results are shown below.

Configuration Time to boot
Original system, 4GB RAM, 5400 rpm 500GB boot
76 sec.
System upgraded to 8GB RAM, 5400 rpm 500GB
boot disk
84 sec.
System upgraded to 8GB RAM and SSD boot disk 24 sec.


The 60GB SSD, now my boot drive, has almost 24GB (about %40) of
free space. This should provide the free space needed for efficient operation and keep me from having to repeatedly prune large files. Once I remove all but the ‘Users‘ folder from the old drive, I will gain about 35GB of free disk space. That will leave me with the system and applications on a small, fast dedicated drive, and a separate internal data drive for my user files.

One Post-Upgrade Issue

I went to run a Time Machine backup a day or so after I had completed adding the SSD, only to find that it kept failing. A little investigation revealed that Time Machine gets confused when an existing single drive is split into separate boot and data drives. I reformatted the external 750GB drive I use for Time Machine backups and ran a fresh backup. The new full backup ran properly and took over 8 hours to complete (in great part due to the USB 2.0 controller on my Mac Mini and having to make the initial backup of 456GB of files), but now Time Machine backs up both internal drives.


The bottom line is you should upgrade your memory to at least 8GB if your system can take it. Likewise, replace your boot drive with an SSD. These upgrades cost below $200 and will extend the useful life of your Mac for years.

See my other Mac OS X articles

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