How To Clear Scratch Disk Photoshop

What is a Scratch Disk?

A scratch disk is a designated area on your hard drive that Photoshop uses as virtual memory when your system doesn’t have enough RAM to perform an operation. Think of it as Photoshop’s temporary workspace where it stores:

• Working files and layers that don’t fit in RAM
• Undo and history states
• Clipboard data
• Temporary files generated during complex operations

By default, Photoshop uses the hard drive containing your operating system as its primary scratch disk. When this space fills up, you’ll encounter the infamous “Scratch Disk Full” error that prevents you from continuing your work.

Signs Your Scratch Disk is Full

You’ll know your scratch disk is running out of space when you experience:

• Direct “Scratch Disk Full” error messages
• Significantly slower performance in Photoshop
• Inability to save files
• Photoshop freezing or crashing during complex operations
• Problems when trying to create new documents

How to Clear Your Photoshop Scratch Disk

Here are several effective methods to clear your scratch disk and get back to designing:

1. Clear Your Photoshop Cache

Photoshop uses three different memory caches that power features like “Undo” and “History” and allow you to copy images between documents. Clearing these caches can free up significant space:

1. With an image open in Photoshop, click the Edit menu
2. Hover your mouse over Purge to reveal your cache options
3. Select the specific item you want to delete (Clipboard, Histories, or All)
4. Click OK on the confirmation dialog (remember that purging cannot be undone)

2. Delete Temporary Files

Photoshop creates temporary files during editing sessions that sometimes aren’t properly deleted. You can manually remove these files:

On Mac:

1. Close Photoshop completely
2. Press Command+Shift+G in Finder
3. Enter /Users/[username]/Library/Application Support/Adobe/Adobe Photoshop [version]/Adobe Photoshop [version] Settings/Temp
4. Delete all files in this folder

On Windows:

1. Close Photoshop completely
2. Navigate to C:\Users\[username]\AppData\Roaming\Adobe\Adobe Photoshop [version]\Adobe Photoshop [version] Settings\Temp
3. Delete all files in this folder

3. Change Your Scratch Disk Location

Hard drives should ideally never exceed 85% capacity. When you pass that threshold, performance issues become likely. If you find yourself constantly freeing up space, consider changing your scratch disk to another drive with more free space:

1. Click on the Edit menu in Photoshop
2. Select Preferences and click on Scratch Disks
3. Tick or untick the checkboxes to select or remove drives as scratch disks
4. Use the arrows to change the priority order of the drives
5. Click OK and restart Photoshop for changes to take effect

4. Reset Photoshop Preferences

Sometimes, corrupted preferences can cause scratch disk issues. Reset Photoshop preferences by:

1. Close Photoshop
2. Hold Shift+Option+Command (Mac) or Shift+Alt+Ctrl (Windows)
3. While holding these keys, launch Photoshop
4. When prompted to “Delete the Adobe Photoshop Settings File,” click Yes

5. Optimize Your Photoshop Settings

Adjust Photoshop settings to reduce scratch disk usage:

1. Go to Edit → Preferences → Performance
2. Reduce the number of History States (the default is 50, but 20-30 is often sufficient)
3. Under Memory Usage, adjust the slider to allocate more RAM to Photoshop (70-80% is usually optimal if Photoshop is your primary application)
4. Click OK and restart Photoshop

Preventing Future Scratch Disk Issues

Follow these best practices to minimize scratch disk problems:

• Close unused documents: Each open file consumes scratch disk space
• Optimize file sizes: Reduce unnecessary layers and use smaller file formats when possible
• Regular maintenance: Schedule monthly cleanup of temp files and caches
• Monitor disk space: Keep at least 20% of your scratch disk free
• Use external drives: Dedicate a fast external SSD as your primary scratch disk
• Upgrade your RAM: More physical memory means less reliance on scratch disks

When Nothing Works: Emergency Solutions

If you’re still experiencing scratch disk issues after trying the above methods:

1. Free up space immediately: Delete unnecessary files from your system drive
2. Disable scratch disk at startup: Hold down Command (Mac) or Ctrl (Windows) immediately after launching Photoshop to temporarily assign a different scratch disk
3. Reduce file complexity: Flatten unnecessary layers and reduce file dimensions
4. Move to smaller file format: Save as a smaller format like JPEG temporarily to complete your work

Hardware Solutions for Frequent Scratch Disk Issues

If you routinely work with large Photoshop files and encounter scratch disk problems, consider these hardware upgrades:

• External SSD: A high-speed external SSD dedicated as a scratch disk
• Additional RAM: Upgrading your system’s RAM can reduce reliance on scratch disks
• Internal SSD upgrade: Replace your system drive with a larger, faster SSD