Temp files with plenty of memory available

[Andreas Resch]

I just got an error that my scratch disk is full. As I checked, there were three Photoshop temp files in there, although I have plenty of RAM available (about 40GB). Even after starting Photoshop with no file open, a temp file is immediately created. What's that about?

Here's a screenshot of the three temp files ...

[jane-e]

@Andreas Resch 

How much free space do you have and how big are the files you are working with?

https://helpx.adobe.com/photoshop/kb/troubleshoot-scratch-disk-is-full.html

https://helpx.adobe.com/photoshop/using/scratch-disks-preferences.html

Jane

[Andreas Resch]

Free space was about 45GB. But that's not the point. The question is, why is there that much disk space allocated with about 40GB of free RAM (with some file being openened)?

[jane-e]

@Andreas Resch 

It's advised to have a minimum of 100 GB free disk space. More is required with larger files (you didn't answer the file size question). I have 1TB free space.

Sometimes folks get the message when they accidentally choose 1000 inches instead of 1000 pixels, for instance. I'm not saying that that is your issue.

When you get the "scratch disk full" message, you need to either clear space on the drive you are using for scratch space or set up a another drive for scratch space. Read the two help files for details. 

Jane

[Kevin Stohlmeyer]

RAM and Disk Space are two different things.

The error you are getting is about running out of free disk space, not RAM.

[Test Screen Name]

Scratch disk is always allocated, whether there is enough RAM or not. Make sure you have several hundred GB free space on your scratch disk. If it's an SSD never let it get over 90% full or performance will plummet.

[Andreas Resch]

Thanks for the answer. Not going to buy huge SSD's though, just so that Photoshop can fill them up with unnecessary temp files. Maybe some of that AI nonsense shouls be directed towards file and memory management.

[davescm · Accepted solution]

'.....just so that Photoshop can fill them up with unnecessary temp files.'

You misunderstand. Scratch files are not 'unnecessary' but are fundamental to the way Photoshop works. Photoshop uses scratch files as working memory and constantly swaps the data in RAM with that scratch file. Scratch files are used even with large RAM.

Depending on what size the files you are working on, how many files are open, what their content is in terms of layers/smart objects etc, and what exact operations you are carrying out 40GB may be enough scratch space or may be woefully too small. The error message suggests too small in your case.

I have 256GB RAM here and my primary scratch disk has over 800GB free (secondary scratch over 1TB free).

One thing to check though - close Photoshop and those temp scratch files should disappear. If on or more remain, then PS may have crashed at some point and left file(s) behind. If so, it is safe to remove them whilst Photoshop is closed.

Dave

[Andreas Resch]

I start to understand why Photoshop is very slow at times, when an SSD is used instead of RAM - especially for smart objects. While I somehow got used to the stuttering movements of smart objects, it's nothing that should be seen as "normal" just because the system is designed to work like that. From what I've seen, Photoshop has not seen any speed improvements in that regard for years - even though CPU's and GPU's got a lot more powerful.

[TheDigitalDog]

From what I've seen, Photoshop has not seen any speed improvements in that regard for years - even though CPU's and GPU's got a lot more powerful.

By @Andreas Resch

Maybe what you've “seen” but not the case for others. It's correctly been explained to you and pointed out to you that you have insufficient empty drive space (”about 45GB”)!

Of course you could provide a document for upload so anyone with similar or dissimilar systems could run speed test comparisons and videos on your “problematic” sample documents. 

Provide a link and I’ll start....

[D Fosse · Accepted solution]

As Dave says. RAM is just a cache to the scratch disk's main memory.

Raster image editing moves huge amounts of data around, much more than any RAM you may have installed. There is no such thing as "enough RAM". The scratch disk always carries the main load, and then data are shifted to RAM as needed. This is a dynamic process and data goes back and forth continuously..

[Andreas Resch]

Well - that's a bad system. SSD's should kick in once RAM gets low, not from the get go, when plenty of RAM is available. 

[davescm · Accepted solution]

'SSD's should kick in once RAM gets low, not from the get go, when plenty of RAM is available. '

No - that would be inefficient and cause stuttering. What you want is such swapping to happen seamlessly in the background so that the fastest memory always has the right content in it at the right time.

I see no stuttering here on any of three systems :

a. A system with 256GB RAM, RTX3090 GPU and scratch on NVMe drives

b. A system with 64GB RAM, RTX2070ti and scratch on SSD

c. A laptop with 32GB RAM, RTX3070 and scratch on SSD (which is also the system drive)

In all three systems there are several hundred GB available to scratch. The smallest system usually has InDesign and Photoshop open at the same time. The largest system will often have several 3D applications and Photoshop open together.

Dave

[Andreas Resch]

If there are performance issues or not doesn't only depend on the system but moresome what kind of files you are working on. My system shouldn't be the reason for the laggy performance (in some cases). The only bottleneck I can think of could be my Ryzen CPU. But it's not that slow either.

The reason why you have no stuttering might be because you might mostly work on different kind of images than I do. When I edit photos, even drum scans, it's not that bad. But once I start to assemle my game assets, it's a different story. Using a lot of smart objects, layer styles and smart filters is really causing problems. Even if plenty of RAM is up for grabs and the GPU is chilling in the background. And maybe IO processes are contributing a bit to that. I can't know what is shuffled around between RAM and the SSD in such situations. 

[jane-e]

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@Andreas Resch wrote:

Well - that's a bad system. SSD's should kick in once RAM gets low, not from the get go, when plenty of RAM is available. 

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Are you still getting the scratch disk full message or are you able to work again? Unfortunately, arguing with the volunteers on this forum or with Photoshop itself won't solve your issue:

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@jane-e wrote on December 20:

When you get the "scratch disk full" message, you need to either clear space on the drive you are using for scratch space or set up a another drive for scratch space. Read the two help files for details. 

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We are just trying to help you get up and running again and explain how Photoshop works.

Jane

[Andreas Resch]

I switched my scratch disk to another SSD, where there's more space. But that wasn't the reason for opening this thread. It was the confusion about temp files being created and used while plenty of system memory is available. And I'm always thankful for help.

[jane-e]

@Andreas Resch 

I'm glad to hear Photoshop is working for you again!

Jane

[Kevin Stohlmeyer]

The temp files are normally invisible and auto clear out when you close the file or program. The fact that they are a)visible and b) still on your HD when closed tells me that you have a sync/speed issue with read/write to the external SSD. That would cause these files to stack up and not release your HD space.

[davescm]

Scratch files are visible in Windows Explorer whilst Photoshop is open, that is normal. They should be removed when Photoshop closes though.

Dave

[Kevin Stohlmeyer]

Learned something new today - I've never noticed my temp files on Windows before. I'll have to watch my scratch disk location next time. I do know on Mac they are hidden and assumed the same for both OS.

[D Fosse]

If you have the scratch disk in the default location on the C drive, it goes to the Windows Temp folder. So it's not immediately visible unless you specifically look for it.

With scratch disk on any other drive, it goes directly to the root of that drive, so you see it right away.

[Kevin Stohlmeyer]

Ah that would be why. I have my default location set for Windows scratch disk, not an external.

[Per Berntsen]

On the C drive, the Photoshop temp files will be in C:\Users\User name\AppData\Local\Temp.

You might have to set Windows to show hidden files to see them.

Curiously, opening InDesign will create a Photoshop Temp file in this folder, size 0 bytes, and it doesn't seem to increase in size as you work in InDesign.

[Kevin Stohlmeyer]

I'm ok with my setup. Was just noting that I don't normally see my temp/scratch files on my Windows machine. I also don't have the same issues as the OP.

[Per Berntsen]

I understand that you don't have any issues with this, I just wanted to provide information about the whereabouts of the Temp files on the C drive. I had no idea where they were until I searched for them a few minutes ago.