When you open a file in Adobe Photoshop, you get an error stating “Scratch disk is larger than expected”.
The scratch size indicator in the status bar at the bottom of the Photoshop document window displays a large amount of scratch disk space, regardless of the size of the file.
When Photoshop CS starts, it allocates a larger amount of scratch disk space than previous versions of Photoshop. (The amount of scratch disk Photoshop allocates is based on the amount of RAM on the computer and the percentage of RAM set in the Photoshop Memory preferences.)
Download and install the Adjusted Refresh plug-in:
The Adjusted Refresh plug-in reduces the initial scratch disk usage when you start Photoshop, and reduces the size of the Photoshop image tiles. The smaller tiles allow the display to redraw in smaller pieces, reducing the time needed to preview some filter updates.