If you’ve ever had to deal with a Photoshop “scratch disks full” error then you probably know what a rude interruption this can be to your workflow. The last thing any Photoshop user wants to do is put the mouse or pen down and troubleshoot during an editing session.
In this tutorial, we will explain what’s causing the “scratch disks full” error and how to fix it. We’ll also share best practices to prevent this error from happening in the future.
What Is the Photoshop “Scratch Disks Full” Error?
The Photoshop “scratch disks full” error basically means that Photoshop can’t function because there’s no space on your hard drive for it to assign its temporary files to operate.
It’s also likely that these files have overwhelmed the RAM assigned to handle some of Photoshop’s basic operations, which results in overall sluggish performance or the dreaded “scratch disks full” error.
One of two things needs to happen when you get the “scratch disks full” error (and you may need to do both). Space needs to be cleared so that Photoshop can function. You may also need to create new space in the form of additional scratch disks and perhaps the addition of an external hard drive.
Let’s take a look at the troubleshooting steps you can do, in a practical order, so that you can quickly clear out the “scratch disks full” error and continue your work in Photoshop.
Fix #1: Clean Up the Hard Drives on Your Computer
The first step should always be to clean up your hard drives on your computer. Mac and Windows users can run their native disk cleanup utilities, like the space-clearing Disk Cleanup tool for Windows. Trusted third-party apps like CC Cleaner can also be used.
The reason we list this step first is that it potentially removes interference from your computer’s OS and any programs running in the background.
Here’s a general list of the files that your disk cleanup utilities will remove:
- Browsers: temporary internet files, history, cookies, recently typed URLs, index files, and last download location.
- Operating System: empty recycle bin, temporary files, clipboard, memory dumps, chkdsk file fragments, log files, error reporting, and DNS cache.
Best Practice: Take a moment and run your disk cleanup program after every session on your computer. This will help prevent Photoshop “scratch disks full” errors from happening, and will also improve your computer’s speed and performance in day-to-day use.
Also, keep minimal apps open on your computer while using Photoshop, including email, social media, and other resource-intensive programs.
Fix #2: Access and Troubleshoot Photoshop Scratch Disks
Let’s get right to the heart of the matter and check your Photoshop scratch disks. In most cases, your scratch disk will default to the drive that Photoshop was installed on, which is typically the C Drive.
To access your Photoshop scratch disks in Windows, go to Edit > Preferences > Scratch Disks.
On Mac, go to Photoshop CC > Preferences > Scratch Disks.
Make note of the available free space and which hard drive is checked. If you have little space left in the hard drive that’s being used, choose the other one.
The D Drive will likely have more available space, and checking the box will make the drive available. If both of these drives are nearly full, then you may need to add an external drive (explained later in this tutorial).
Note that it’s perfectly fine to have all the drive boxes checked.
Best Practice: Occasionally check back to see if your preferences have been reset due to any Photoshop upgrades or crashes. You may have to tick the appropriate drive(s) once more.
Fix #3: Delete Temporary Photoshop Files
If you’ve experienced several Photoshop crashes or have forced the program to shut down before closing it properly, then there may be large temporary files left behind that are causing disk space/RAM issues.
These files may be safely deleted without harming Photoshop functionality. To do so, locate the PST files (on older Photoshop versions) or Photoshop Temp files, and delete them.
On your computer, go to C:/ > Users > “YourUser” > AppData > Local > Temp.
Best Practice: Heavy Photoshop users may find it helpful to delete these files monthly or even weekly.
Fix #4: Increasing RAM Usage and Processor Settings for Photoshop
If the “scratch disks full” error persists, and you’ve noticed Photoshop operating sluggishly over time, you may want to increase the amount of RAM available for Photoshop to use.
In Photoshop, go to Edit > Preferences > Performance. Move the slider to the desired percentage. It’s advisable to increase available RAM to no more than 80 percent so that your computer won’t run slow.
Additionally, you may opt to check the Use Graphics Processor box. This will enable a number of Photoshop functions to run more smoothly.
Fix #5: Purging the Photoshop Cache
Another place to consider cleaning is the Photoshop cache files. This method will allow you to clean up the clipboard, histories, video cache, or all of these files.
In Photoshop, go to Edit > Purge > All.
Keep in mind that this method will also clear any recent steps you performed in Photoshop, so all of your previous undo and redo actions will not be available until you start using Photoshop again.
Best Practice: Scratch disks full message aside, purging the cache occasionally is a good idea to ensure that Photoshop runs smoothly. The best time to do this would be directly after an editing session.
Fix #6: Clear the Aspect Ratio Values in Photoshop
This method is likely an afterthought for many users (or unheard of entirely) because the tool is hiding in plain sight. When using the Crop tool, there’s a Clear box to erase the aspect ratio values. If you click it, it will erase any of the entries you may have made previously.
But don’t worry, clearing the aspect ratio values doesn’t mess with any of the default Photoshop settings. Just like temporary files or clipboards, these are excess files that have been stored from previous editing sessions and can be cleared without worry.
Fix #7: Adding an External Hard Drive
If both your C and D drives are near full capacity, or you’re still getting the “scratch disk full” message after checking both drives in Preferences, then it’s time to add an external hard drive. Short of more advanced troubleshooting like creating a hard drive partition, or replacing your computer entirely, this will guarantee that Photoshop has ample space to operate.
To proceed, simply install your external hard drive and access your scratch disks in Preferences once more. You should see your external drive listed—check the box.
You may encounter unrelated Photoshop errors during regular usage that result in all the default settings being restored. When this happens, you may have to access Preferences once again to check the appropriate drives for your scratch disks.
Best Practice: Many professional photographers and expert Photoshop users use a dedicated external hard drive for each project. Adding an external hard drive for editing batches and large files greatly reduces the risk of the dreaded “scratch disks full” error.
Fix #8: What to Do If Photoshop Won’t Open Due to “Scratch Disks Full” Error
In extreme situations, Photoshop may not open at all, but will instead inform you of the “scratch disks full” error via a popup box.
When this happens, you will need to launch Photoshop while holding Ctrl + Alt on Windows or Ctrl + Option on Mac. This will allow you to access Photoshop through the backdoor and fix the issue.
Fix #9: Defrag Your Hard Drive
Photoshop requires unfragmented free space on your hard drive in order for it to function properly. Therefore, it’s advised to run your disk defragmentation program in order to free up any fragmented space.
Best Practice: Defrag your hard drives on a monthly basis to keep your computer and Photoshop running smoothly.
Fix #10: Consult Adobe’s Support Community
Adobe Photoshop is always changing and adding new features almost monthly. This means that troubleshooting steps will likely evolve in time.
If you’ve tried all the troubleshooting steps here, and you’re still experiencing “scratch disks full” errors or other issues, there could be other options to try. A great reference to keep in mind is the Adobe Support Community.
From there, you can access communities built around Adobe products, including Photoshop. You can ask any questions you may have about Photoshop issues, and you’ll likely receive help from fellow Photoshop users.
The “Scratch Disks Full” Error Is a Scary Issue for Photoshop Newcomers
Fortunately, once you encounter the “scratch disks full” error a few times and conquer it, it becomes an easy fix. It’s much like a mild headache; you know it will happen at some point, but it won’t be a big deal since you know how to handle it.
Another way to look at it is like a rite of passage. Most Photoshop users will encounter the “scratch disks full” error at some point. But there’s absolutely no reason to fear it. The fixes presented here will help you get back to the important work of your Photoshop creations in no time.