A scratch disk is an area of the hard drive that’s used as storage to help Photoshop handle large images. Scratch disks help to ensure efficient results when editing high-resolution pictures. If possible, the disk should be on a separate hard drive from Photoshop and your Main OS. Our tutorial below explains how to go about setting up such a disk
1.Open Scratch Disk Options
In Photoshop, click edit > preferences > plug-ins > scratch disks. This is the same for both Mac and PC versions of Photoshop.