How To Clear Scratch Disk Photoshop

This guide explains how to approach how to clear scratch disk photoshop, including the preparation, practical steps, common mistakes, and final checks that help you finish with confidence.

15-30 mins Time needed

Easy to Moderate Difficulty

Data loss from force-quitting Watch out for

Before You Start

Check first: Make sure you've saved all your work in Photoshop before you begin. Forcing the program to close or making system changes without saving can lead to losing unsaved progress on your images. Always save your work!

Step-by-Step Instructions

Quick Reference

Common Problems When You Clear Scratch Disk Photoshop

Even with clear instructions, you might run into a few common issues when trying to manage Photoshop's scratch disk. Knowing what these problems are and how to fix them can save you time and frustration.

Photoshop Keeps Saying Scratch Disk is Full After Clearing Cache

If you've purged Photoshop's caches and still get the error, it means the problem isn't just with Photoshop's active memory. The hard drive designated as the scratch disk is still too full. The cache clear only helps with temporary data from the *current* session. The fix is usually to either choose a different, emptier drive as your scratch disk (see Step 3) or to manually free up significant space on the current scratch disk drive by deleting non-Photoshop files (see Step 4).

Can't Find Photoshop Temp Files to Delete

Temporary files can sometimes be hidden by your operating system to prevent accidental deletion. If you're searching for "Photoshop Temp" files and can't find them:

Windows: Ensure "Show hidden files, folders, and drives" is enabled in File Explorer options. Go to File Explorer, click "View" tab, then "Options" > "Change folder and search options" > "View" tab. Check "Show hidden files, folders, and drives".
macOS: In Finder, you can press Shift + Command + . (period) to show or hide hidden files. Search again after making hidden files visible.
Also, make sure Photoshop is completely closed before searching, as open programs can lock their temporary files.

No Other Drives Available for Scratch Disk

If you only have one hard drive in your computer, you won't be able to select a different scratch disk. In this case, your only option is to aggressively free up space on that single drive (refer to Step 4). This might mean uninstalling unused software, moving large personal files (like videos or old projects) to external storage, or using a cloud service to offload data. Consider adding an external SSD for use as a dedicated scratch disk if frequent issues arise.

Photoshop is Still Slow Even After Clearing Scratch Disk

A full scratch disk is just one reason for slow Photoshop performance. If clearing it doesn't help, consider these other factors:

Insufficient RAM: As mentioned in Step 6, more RAM reduces reliance on the scratch disk.
Slow Processor: An older or less powerful CPU (Central Processing Unit) can bottleneck Photoshop operations.
Outdated Graphics Card: Photoshop increasingly uses the GPU (Graphics Processing Unit). Ensure your graphics drivers are up to date and your card meets minimum requirements.
Very Large Files: Working with extremely high-resolution images or files with hundreds of layers will always be demanding, regardless of your setup. Optimizing your workflow (e.g., merging layers, reducing image size if possible) can help.

Advanced Tips for How To Clear Scratch Disk Photoshop

Once you've mastered the basics, these advanced tips can help you optimize your Photoshop workflow and prevent scratch disk issues from recurring.

Set Up a Dedicated External SSD for Scratch Disk

If your internal drives are limited or slow, investing in a fast external Solid State Drive (SSD) can be a game-changer. Connect it via USB 3.0, USB-C, or Thunderbolt for the best speeds. Then, in Photoshop's Preferences > Scratch Disks, set this external SSD as your primary scratch disk. This dedicates a fast drive solely to Photoshop's temporary files, leaving your internal drives free for the operating system and other applications.

Allocate More RAM to Photoshop

Photoshop allows you to control how much of your computer's available RAM it can use. Giving it more RAM reduces its need for the scratch disk. Go to Edit > Preferences > Performance (on Windows) or Photoshop > Preferences > Performance (on macOS). Under "Memory Usage," you'll see a slider labeled "Let Photoshop Use." Dragging this slider to a higher percentage (e.g., 70-80%) can dramatically improve performance. Be careful not to allocate too much, as your operating system and other applications also need RAM to function correctly.

Optimize Photoshop Performance Settings

In the same "Performance" preferences panel, you can adjust other settings:

History States: This determines how many "undo" steps Photoshop remembers. While useful, a high number can consume a lot of scratch disk space. Reducing it from the default of 50 to perhaps 20-30 can save space.
Cache Levels: This setting affects how Photoshop stores image data. Higher cache levels generally lead to faster screen redraws but use more memory. For large files, a setting of 4-6 is often a good balance.
Graphics Processor Settings: Ensure "Use Graphics Processor" is checked, and review "Advanced Settings" to make sure the "Drawing Mode" is set to "Advanced" for optimal GPU acceleration.

Regularly Clean Your Disk Drives

Make disk cleanup a routine part of your computer maintenance, not just when Photoshop complains. Use your operating system's built-in tools:

Windows: Search for "Disk Cleanup" in the Start menu. It can identify and remove various temporary files, system files, and old downloads.
macOS: Go to Apple menu > "About This Mac" > "Storage" tab > "Manage..." Here you'll find recommendations for optimizing storage, such as storing in iCloud, emptying trash automatically, and reducing clutter.

By keeping your drives lean, you ensure Photoshop always has ample scratch disk space available.

How To Clear Scratch Disk Photoshop FAQ

Q: What is a scratch disk in Photoshop?

A: The scratch disk is temporary storage space on your hard drive that Photoshop uses when your computer's RAM (Random Access Memory) isn't enough to handle open files, history states, and complex operations. It acts as virtual memory, allowing Photoshop to work with larger files than your RAM alone could support.

Q: Why does my scratch disk keep getting full?

A: Your scratch disk often gets full because you're working with very large files, multiple high-resolution documents, many layers, or a high number of history states. It can also happen if Photoshop crashes and leaves behind temporary files, or if the designated scratch disk drive simply doesn't have enough free space for Photoshop's needs.

Q: Can I use an external hard drive as a scratch disk?

A: Yes, you can absolutely use an external hard drive as a scratch disk. In fact, using a fast external SSD (Solid State Drive) connected via USB 3.0, USB-C, or Thunderbolt is highly recommended if your internal drives are slow or full. You can set this up in Photoshop's Preferences > Scratch Disks.

Q: How much free space should my scratch disk have?

A: A general rule of thumb is to have at least 50GB to 100GB of free space available on your primary scratch disk, but ideally, you should aim for even more if you work with very large or complex files. Photoshop needs space that is a multiple of your document size, plus all the history states and other temporary data.

Q: Does clearing the scratch disk delete my Photoshop files?

A: No, clearing the scratch disk, whether by purging Photoshop's caches or deleting temporary files, does not delete your saved Photoshop project files (.psd, .tiff, etc.). It only removes the temporary data Photoshop uses during its operations. However, using the "Purge" command will clear your current Undo/Redo history for the active session, so save your work first!

Final Checklist for How To Clear Scratch Disk Photoshop

Before you wrap up, review this checklist to ensure you've taken all necessary steps to resolve your scratch disk issues and optimize Photoshop performance.

Saved All Work: Ensure all open Photoshop projects were saved before making changes.
Purged Photoshop Caches: Used Edit > Purge > All to clear Photoshop's internal temporary memory.
Checked Scratch Disk Preferences: Verified which drive(s) Photoshop is using for scratch disks and ensured they have ample free space.
Changed Scratch Disk if Needed: If available, directed Photoshop to use a faster, emptier drive as its primary scratch disk.
Freed Up Disk Space: Manually deleted unnecessary files from the designated scratch disk drive.
Emptied Recycle Bin/Trash: Ensured deleted files were permanently removed from your computer.
Restarted Photoshop: Always restart Photoshop after changing scratch disk preferences for changes to take effect.
Considered RAM Upgrade: If issues persist, thought about increasing your computer's physical RAM.
Regular Maintenance Plan: Planned for routine disk cleanups to prevent future scratch disk problems.