AVG Signal Blog Performance Cleaning How to Clear Photoshop Scratch Disk on Mac

Written by Samuel Kellett
Published on July 14, 2021

What is a scratch disk?

A scratch disk is the temporary memory bank Photoshop uses while running. Programs like Photoshop can access the scratch space faster than going through your computer’s RAM, which increases performance. But as your main drive fills up with data, there’s less room left for your scratch disk.

This article contains:

    What does “scratch disk full” mean?

    “Scratch disk full” means the program you’re using has filled up the space on your hard drive that it was using for its scratch disk. One likely cause of this is temporary files from old projects that are taking up too much space. 

    These files are separate from any permanently saved files you have, but Photoshop holds on to them until you decide to delete the temp files or save them.

    It’s also possible that you’re getting the “scratch disk full” error message — or a similar message, like “could not initialize photoshop because the scratch disks are full” — because your hard drive is too full for Photoshop to create the scratch space it needs to run properly. Fortunately, there are a few methods for fixing this issue.

    How to clear scratch disk on a Mac

    There’s no way to automatically empty your scratch disk on Mac, but you can keep the problem from happening in the future with an automatic solution. AVG TuneUp automatically clears your cache and keeps your computer clear of temporary files and other junk that causes congestion and slows you down. 

    AVG TuneUp’s AI-powered Photo Finder even sorts through your photos to find the best versions of duplicate shots so you can get rid of the ones taking up space.

    If you’d like to clear your scratch disk manually, there are a number of solutions you can try:

    Here’s a step-by-step guide for using these manual solutions. Just to be safe, save your important Photoshop files before you start.

    Here’s how to get rid of that pesky Photoshop scratch disk full message:

    Option 1: Clear Photoshop cache

    If you want to empty the scratch disk in Photoshop, a good place to start is to empty your photoshop cache. While Photoshop automatically deletes the cache when you exit the program, some items can be missed.

    Here’s how to thoroughly clear the Photoshop cache:

    1. Open Photoshop.

    2. Open the Edit menu and choose Purge.

      To clear your Photoshop cache, look under Photoshop's "Edit" menu, and hover over "Purge"
    3. Select All to clear every cache, or select any individual cache you want to clear (Clipboard, Histories, or Video Cache).

      While hovering over Purge, use the menu that opens to select the cache you want to clear.

    You can also clear other caches on your Mac to get a tidier, faster machine. While you’re at it, try using a browser cleaner tool to easily clear your browser cache and clear your cookies at the same time.

    Option 2: Delete Photoshop temp files

    Photoshop keeps temp files as a backup in case your program or computer crashes, but it doesn’t delete them once you’re done with a project. So these junk files can hang around and take up lots of space.

    Here’s how to delete Photoshop temp files:

    1. Save all your projects to avoid accidentally deleting something you’ll miss.

    2. Exit your Adobe programs.

    3. Search in your Finder for /tmp and open the tmp folder.

      Type "/tmp" into the finder to discover if you have temporary Photoshop files.
    4. See if you have any folders named Photoshop Temp followed by a string of numbers. If you do, delete any files in them ending in .tmp.

    5. Empty the Trash.

    Another way to clear space on Mac is to check your Other storage, a place where less common file types are stored. Some of the files kept here should not be deleted, so check out our guide to finding and deleting Other storage on Mac before you start.

    Option 3: Delete hidden Photoshop files

    You can also search for hidden files that may be taking up space. Here’s how to find and remove hidden Photoshop files:

    1. Open Finder.

    2. Find the Photoshop folder and press Command + Shift + Period.

    3. Any existing hidden files will appear as grayed out folders. Drag the files to the Trash.

    4. Empty the Trash.

      Any hidden files will appear as grayed out files.
    5. To stop showing hidden files, press Command + Shift + Period again.

    Option 4: Clear disk space

    Photoshop requires a minimum of 10GB of space to create a scratch disk, but 20GB is recommended. If you’re getting an error message about your scratch disk, you may need to free up disk space on your hard drive.

    There are several ways to clear your hard drive, which can also speed up your Mac in the process.

    One easy way to start clearing more space is to delete any old videos or games you no longer use. You can also search for large files in Finder by sorting them by size and deleting any you don’t need.

    Besides large files on your computer, there may be duplicate files, old caches, bloatware, and other unnecessary hidden items taking up space on your drive. 

    AVG TuneUp finds and removes all this clutter and hidden digital leftovers, and keeps your Mac in tip-top shape with automatic maintenance. Plus, it can streamline your photo library by identifying blurry, duplicate, or otherwise low-quality shots and helping you easily delete what you don’t want to save — which will free up even more space.

    Option 5: Change scratch disk location

    Another way to fix scratch disk errors on Photoshop is to change the scratch disk location to another drive with more space. If you have multiple drives on your computer, you can designate one as your scratch disk to ensure you have enough space.

    Here’s how to change your scratch disk location in Photoshop: 

      1. Open the Photoshop menu and click Preferences.

         To change your scratch disk location in Photoshop, look under the Photoshop menu and hover over "Preferences"
      2. Select Scratch Disks on the menu that opens up.

        While hovering ver "Preferences," select "Scratch Disks" from the menu that opens up
      3. Now choose a different drive to be your scratch disk.

         Changing the drive for your Photoshop scratch disk on Mac.

    If an error is preventing you from opening Photoshop, you can hold down the COMMAND and OPTION keys while the program is trying to launch to change the scratch disk location.

    Option 6: Get a new SSD

    You may be able to upgrade the RAM on your Mac if it’s an older model. For newer Macs, you can deal with disk space issues by using an external drive as your scratch disk. If you’ve tried all the tips above and your Mac is still lagging, an external drive may be worth the investment. An SSD (solid state drive) will give you greater performance than an HDD (hard disk drive), but at a higher price. 

    Despite the expense, SSDs win over HDDs when it comes to photo editing in Photoshop or video editing in Premiere. All the data on an SSD can be accessed instantaneously, letting you load those hefty files in seconds.

    Clean up quickly with AVG TuneUp for Mac

    The problem with manually cleaning your Mac is that temp files, caches, and other digital leftovers start to build up again almost immediately. Before you know it, you can get that “could not complete your request because scratch disks are full” error message again. 

    AVG TuneUp keeps your computer running fast and clear of clutter with automatic maintenance. Plus, it’ll prevent junk files from building up, while the built-in Photo Finder feature will tidy up your photo library. Download AVG TuneUp today to streamline your Mac and get back to editing your photos error-free.

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    Samuel Kellett