The Adobe Photoshop scratch disk is the hard drive in the computer. Photoshop uses the hard drive as a temporary “swap” space, or virtual memory, if not enough RAM is available. If you receive an error stating the scratch disk is full then this means that the local hard drive does not have enough available space for the file(s) you are working on. The local hard drive in the computer is not connected to your network home drive space in anyway.
To solve this error try the following:
Firstly, check how much free space Photoshop reports is available. To do this, open Photoshop and go to Edit > Preferences > Performance. Then look under Scratch Disks to see how much space is free.
Photoshop CC also displays RAM and scratch disk usage and allocation in the Scratch Sizes section of the status bar. The number on the left indicates the RAM used and scratch disk space allocated to Photoshop. The number on the right indicates the amount of RAM that Photoshop can use for image storage or scratch disk. Photoshop CC uses more memory than previous versions.
Option 1 (Only applicable in College)
If the hard drive space is very low then try running Disk Cleanup.
- Go to Applications which is located on the Desktop
- Go into All
- Run the Disk Cleanup application. This can take a few seconds or a few minutes depending on how much can be cleaned up.
The Purge command lets you free memory used by the Undo command, the History panel, or the clipboard.
Choose Edit > Purge, and choose the item type or buffer you want to clear. If it is already empty, the item type or buffer is dimmed.
Note: The Purge command permanently clears from memory the operation stored by the command or buffer; Purge cannot be undone. For example, choosing Edit > Purge > Histories deletes all history states from the History panel. Use the Purge command when the amount of information in memory is so large that Photoshop performance is noticeably affected.
Image size and the number of files open in Photoshop will affect scratch disk and RAM usage. Firstly, consider closing any open files that you are not actively using. If the image you are working on is particularly large consider reducing the size. To check the image size in Photoshop go to Image > Image Size. If you are planning to print an image A3 in size then the size should be about 4900 pixels x 3500 pixels with the resolution set to 300 Pixels/Inch. Increasing the image size will not necessarily result in a better print if it exceeds what the printer is capable of. For further guidance about how image size and resolution works in Photoshop visit https://helpx.adobe.com/photoshop/using/image-size-resolution.html.