Photoshop not releasing scratch disk space

[CrankshaftStudio]

Hi - apologies if this question exists. I ran a search and only found one post about it from 2017.

I am running PS 24.1.1 and Mac OS Ventura 13.2

When I edit images, Photoshop keeps eating up scratch disk space but then doesn't release it. I start with 160GB available on my local HD and after a few edits to a few images it's down to 20GB available. Some of the files are large, so I kind of understand. But when I save down and close the images, only a small fraction of the space is released - i.e. there is now 25GB available. Purge All does not help if it's even available (it grays out if no images are open of course). The only way to get all of the space back is to completely quit out of PS and relaunch. Then all of a sudden there is 158GB (2gigs used by the image for example - normal).

With the larger files I am working with them one at a time, so I would expect the space to be released when I save and close. But that is not the case and causes save errors after a few images due to the scratch disk being full, even though it is not full.

Is this a known issue or is anyone else experiencing this? It gets frustrating when I'm working on multiple images and then I'm out of space and can't save down even though there is plenty of space available. Any input is much appreciated.

[Kevin Stohlmeyer]

That is expected behavior for Photoshop - Scratch Disks do not completely release until the application is quit.

And you are also correct 160 GB is not enough Scratch Disk space - try getting some SSD externals with USB-C connections for storage to free up your main HD.

[CrankshaftStudio]

So you're saying that everytime you edit, save and close a large image (say 20GB), you have to quit photoshop completely before you can edit the next one unless you have TBs of free space - and that is normal to you?

I've never had that happen on any previous version of Photoshop (since Photoshop 4 in the 90s). Everytime when I've saved and closed I would get my space back. This just started happening for me when I installed 2023.

[Trevor.Dennis]

I don't know how far back this goes, but it is certainly way back before the current version.  Yes, it is annoying, and you don't even clear the temp files using Edit > Purge > All.

I have 64Gb RAM and never see the full Photoshop allocated RAM com close to being completely used.  Right now I have nothing open, and a 7Gb temp file with today's date.  Go figure.  I can see anything up to 200Gb of temp files over several files.

Note: temp files become orphaned if Photoshop does not shut down properly, so it is worth checking the root directory of your scratch drives periodically.  I invariably find Photoshop temp files with old dates on them.  

[CrankshaftStudio]

Interesting. I haven't experienced this until recently. I wasn't sure if it was PS or the new Mac OS that caused it since I updated both within a couple of weeks. It may have been happening before and I just didn't notice it. I got a scratch disk error and dumped about 300GB from my local drive to a backup to clear space. Then about 20 minutes and a few edits later, I got the error again. That's when I realized what was happening.

It does seem to clear fine for me if I fully quit Photoshop. So I don't think I have a shut down issue with the app. And I'm aware that Purge doesn't clear everything while you have an image open, but if I save and close an image, I can't figure out why it's holding that data. At that point it should purge all temp data I would think and only use the RAM necessary to run the app.

Well, just an annoyance for now then I guess. Thanks for the input.

[D Fosse]

I can't figure out why it's holding that data. At that point it should purge all temp data I would think and only use the RAM necessary to run the app.

Because it's much faster than requesting it from the OS all over again, every time. A typical Photoshop session involves opening and closing lots of files in rapid succession. This is how it runs actions, for instance.

Both scratch disk and RAM have always worked like this in Photoshop. They are just two sides to the same coin, both are working memory. The scratch disk is main memory, RAM a fast access cache for the most current items.

It's even more important now, when NVMe drives are so fast that it becomes more a direct extension of RAM.