Scratch disks full error when saving

[Naomi5DAF]

Hi,

The 'scratch disks are full error' has been occuring intermittently for about 6 months and occuring when I try to save a file.

I am working on large documents 15,000x15000 (643M), one at a time.

I have checked the cache in Photoshop. Deleted temp files and cleaned up my files. I currently have 257GB available space on hard-drive (see pic). System data is using around 256GB, when Photoshop is open. When Photoshop is closed it drops down to 5.6GB.

I am using macOS Monterey version 12.4, apple M1, 16GB memory.

I have called AppleCare to check that it wasn’t a Mac issue. We ran first aid on the drives. I have nothing else running at the time, only Photoshop. The employee at Mac/Applecare thought that the problem could be an error in the Adobe app reading the information (storage) incorrectly from Mac hence causing the problem of the app thinking that there is no space.?

Thanks, Naomi

[Lumigraphics]

I was using a little desktop calculator and it wouldn't do big numbers 😐

[Naomi5DAF]

So how much space Dave do you think would be suitable to have 1.89 GB? I have 257GB free of disk space.

[davescm]

If 257GB free is dropping to 5.6GB free when you are working on a typical large file, then I would be looking to make 500GB-1TB available for scratch.

As an aside, you may want to consider whether you really need such a large document (15,000 x 15,000 px). Don't fall into the common trap of making a document larger than needed. A physically large print tends to be viewed from a greater distance so the resolution (ppi) can be lowered without any ill effects. Too high a resolution is wasted as it will not be visible at normal viewing distance. 

As a guide, you can calculate the ppi required using:    ppi needed = 6878/Viewing distance in inches.

So a 10 feet by 10 feet print viewed from 10 feet away needs 6878/120 = 57ppi

The same print at 20 feet by 20 feet from 20 feet away only needs 6878/240 = 28 ppi

Dave

[Naomi5DAF]

Thanks. I have decreased my Template file size to 602MB, a lot smaller than the last file. Though i will still need to access and work on those large old files and I cannot resize as it ruins the seamless pattern. I am looking at getting an SSD thunderbolt external hardrive to free up space on my mac. I have also done a complete wipe and re-install of Mac OS to see if this was the problem. Now it is a waiting game.