Mac OS X 10.2 and later versions have automatic processes that clean up fragmented files from the hard drive, but it can get to the point where you still need to defrag an older, slower-performing hard drive in your Mac. One of the simplest and most user-friendly methods is to use a trusted third-party defragmentation program.
<strong>Reasons to Defrag Your Mac Hard Drive</strong>
If your current Mac hard drive is more than 90 percent full, it’s a good idea to use some defragmention software. Downloading many large files, namely video files, can also further fragment your Mac hard drive over time. Note that Macs running operating systems older than Mac OS 10.2 aren’t compatible with most modern defrag software, so it may be a challenge to find one that will work with this type of system.
<strong>Using Software to Defragment</strong>
Before choosing and installing a defrag program for your Mac, make a current backup of all your important files. Also consider freeing up some hard drive space by moving non-essential files to an external USB hard drive or to your iCloud library. One of the most recommended programs to use to defrag your Mac is called iDefrag, which is available for $30. Once you’ve purchased and installed iDefrag or a similar program, open the utility and follow the instructions for defragging your Mac. Give the process plenty of time to complete, and be sure not to move your Mac anywhere until the defragging is finished. You’ll usually be prompted to restart your machine as well.
<strong>An Alternate Defrag Method</strong>
If you have your iMac’s original install disc handy, you can also clean up a good deal of fragmented files by rebooting the system from the install disc. Insert the disc in your iMac and restart while holding down the “C” key on the keyboard. You’ll then be prompted to select your language from a list of options in the install disc’s window. After this step, select “Disk Utility” from the “Utilities” drop-down menu and run this tool to erase and reformat your Mac’s hard drive. Be sure you’ve backed up any files you want to keep onto an external hard drive or other backup location.