How to Clear Scratch Disk in Photoshop

Updated 15 November 2026 · Standard formula, shown below

When Photoshop runs out of memory, it uses a designated hard drive space called the scratch disk. If this disk fills up, you’ll see errors like “Scratch Disk Full” and the program may slow down or crash. This guide shows you how to clear and manage your scratch disk to keep Photoshop running smoothly.

What You’ll Need

Access to Photoshop (any recent version)
Administrator rights on your computer (to change system settings if needed)
At least 10-20 GB of free space on your primary drive (recommended)

Step-by-Step

Close Photoshop completely. Make sure no Photoshop processes are running in the background (check the system tray or Task Manager on Windows, or Activity Monitor on Mac).
Delete temporary files. Photoshop stores scratch files with a .tmp extension in the system temp folder. On Windows, press Win + R, type %temp%, and press Enter. On Mac, open Finder and press Cmd + Shift + G, then type /tmp. Look for files starting with “Photoshop” or “~PST” and delete them. Empty the Recycle Bin or Trash afterward.
Clear Photoshop cache files. Navigate to Photoshop’s cache folder: on Windows, it’s usually C:\Users\[YourUsername]\AppData\Roaming\Adobe\Adobe Photoshop [Version]\Adobe Photoshop [Version] Settings. On Mac, it’s ~/Library/Application Support/Adobe/Adobe Photoshop [Version]/Adobe Photoshop [Version] Settings. Delete the Cache folder inside it (Photoshop will recreate it).
Free up disk space. Empty your Recycle Bin/Trash, uninstall unused programs, and use a disk cleanup tool (like Disk Cleanup on Windows or Storage Management on Mac) to remove temporary files, system caches, and old downloads.
Restart Photoshop. Launch Photoshop again. It will create a fresh scratch file with the available space.
Change scratch disk settings (if the problem persists). Go to Edit > Preferences > Scratch Disks (Windows) or Photoshop > Preferences > Scratch Disks (Mac). Uncheck the current disk (usually C:) and select a different drive with more free space. Click OK and restart Photoshop.

Common Mistakes

Not closing Photoshop before deleting temp files. If Photoshop is running, it may lock the temp files and they won’t be deleted, or you might cause corruption.
Deleting the wrong files. Only delete files that clearly belong to Photoshop (e.g., names starting with “Photoshop” or “~PST”). Deleting other temp files could cause system issues.
Choosing a slow or full drive as scratch disk. A nearly full drive won’t help. Also, avoid using a USB flash drive or a slow external drive—it will make Photoshop sluggish.
Setting scratch disk to the same drive as the operating system. This is often the default, but if that drive is low on space, it’s better to use a different internal drive.

Tips

Keep at least 20% of your primary drive free. Photoshop needs room for scratch files, and the OS also needs space for virtual memory.
Use a dedicated SSD for scratch. If you have a spare internal SSD, set it as the scratch disk for faster performance.
Regularly purge clipboard and history. In Photoshop, go to Edit > Purge > All to free up memory. This doesn’t clear the scratch disk directly, but it reduces the amount of data written to it.
Close unused documents. Each open document uses memory and scratch space. Close tabs you’re not working on.
Increase RAM allocation. In Preferences > Performance, increase the RAM usage for Photoshop (but leave at least 2-4 GB for the OS). This reduces reliance on scratch disk.

Troubleshooting

Still getting “Scratch Disk Full” after clearing? Check if any other program is consuming massive disk space (e.g., video editing software, virtual machines). Free up more space or add another drive as a secondary scratch disk.
Photoshop won’t start at all? Hold down Ctrl + Alt + Shift (Windows) or Cmd + Option + Shift (Mac) while launching Photoshop to reset preferences. This will also clear the scratch disk settings to default, which may help.
Deleted temp files but Photoshop still shows low space? The scratch file might be hidden. On Windows, enable “Show hidden files” in File Explorer and look for a file named Photoshop Temp in the temp folder. On Mac, use Finder’s “Go to Folder” and type /private/var/tmp to find it.
Scratch disk is set to a drive that no longer exists? Go to Preferences > Scratch Disks and re-select a valid drive. If Photoshop can’t open, reset preferences as above.
Performance is still slow after clearing? The scratch disk is not the only factor. Check your RAM usage, close background apps, and consider upgrading hardware if you work with very large files.

Frequently Asked Questions

What exactly is the scratch disk?

The scratch disk is a portion of your hard drive that Photoshop uses as a temporary workspace when your RAM is full. It stores parts of your document and history states.

Can I disable the scratch disk?

No, Photoshop requires a scratch disk. You can only change which drive it uses. Disabling it would cause Photoshop to crash on large files.

How much free space should I have on my scratch disk?

At least 10-20 GB, but more is better. For large files (e.g., 1 GB+), you may need 50 GB or more. A good rule is to have 5-10 times the size of your largest working file.

Will clearing the scratch disk delete my work?

No, your saved files are safe. The scratch disk only contains temporary data. You will lose unsaved changes if Photoshop crashes, so always save your work.

Why does Photoshop use the C: drive by default?

It’s the default because it’s the system drive and usually has the fastest access. However, if your C: drive is nearly full, it’s better to use another internal drive.

Does the scratch disk affect performance even when it’s not full?

Yes, if the scratch disk is on a slow drive, Photoshop will be slower when it needs to use it. Using an SSD as scratch can significantly improve performance.

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.