Photoshop: RAM Usage seems high

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  • Updated 7 months ago
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(Apologies if the following seems a bit nebulous but ultimately my question is, I suppose, "Is my copy of Photoshop working correctly? If so, what can I do about crashing and iMac memory pressure issues?")

My iMac keeps crashing and I'm trying to identify the problem. One of the things I've been checking is the Activity Monitor and I've noticed that Photoshop uses a lot of memory (RAM) even for the most basic of processes. It seems to be this causing the most problems.

For example, when Photoshop's first booted up the Activity Monitor shows that's it's using 756MB RAM. However, when I opened a 27MB psd file and resize it from 4126px to 1500px the usage leapt to 4.54GB.

I did nothing else before this and the memory pressure went from green to red during that period and the computer became impossibly slow. 

Other apps running at the same time were InDesign and Bridge along with a smattering of other things (Text Wrangler, Chrome - none of which were using very much RAM).

In the past I was running CS5.5 on a much older machine but never had any problems. Running CS5.5 on High Sierra again caused no problems with the same apps being run concurrently.

However, problems started when I then installed CC (and was then running it on High Sierra). I upgraded to Mojave and then things became more serious as described above.

I've not had this problem and my workflow means that I've needed to work with these apps running concurrently. 

I'm currently running CC 2020 on Mojave 10.14.6
The iMac is a 21.5" 4K 2017 model
Memory = 8GB
Graphics = Radeon Pro 560 4 GB

Thanks in advance for any help or pointers!
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Stuart Gibbins

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Posted 8 months ago

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Adam Jerugim, Employee

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Hi Stuart,

A couple of things: having only 8GB RAM on your system and trying to run multiple apps isn't going to be the best experience. Adding more RAM would certainly help, but wouldn't be a trivial thing to do for your iMac.

Instead, I would suggest launching Photoshop, then selecting Photoshop > Preferences > Performance and set the RAM available to Photoshop to be less than the default 70%. That will limit how much of your total RAM PS can use and give the other running apps access to more RAM.

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Stuart Gibbins

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Hi, Adam,
Thanks for your comment. I can see that I'm likely to need more RAM and that's definitely on my "to-do" list. However, I've not had these problems prior to upgrading Adobe CC and OS which is why I'm surprised. And as I mentioned, I'm using the same apps at the same time as I did on my previous setup using CS5.5 and the same amount of RAM. The only things that have changed are the upgrade to CC and from High Sierra to Mojave.
It just seems to me that a spike from 756MB to 4.54GB to reduce the pixel size of a 27MB file seems excessive. Is this the sort of thing I should expect? Is that normal? I've been working for the best part of 10 years in the same way with no problems until I upgraded so this is why I'm a bit surprised.
I forgot mention that when I close files I'm working on in Photoshop it often takes a while for the RAM usage to drop off and in many instances it stays the same and I simply have to close Photoshop via the Activity Monitor - I can't do it in Photoshop itself as it becomes unresponsive. (I have also uninstalled and reinstalled Photoshop, another thing I didn't mention!)
I work with the Activity Monitor permanently on so I can anticipate a complete freeze and prevent a total system crash. If I don't have the Monitor open, once Photoshop gets top that point, I can't open it (or anything else) because it's too late. The system becomes unresponsive and I have to reboot.
Thanks again,

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This caught my eye re. something I may want to post later. I'm lately running into a situation where my RAM maxes out (using PS2020?) and whatever software I'm closing, some invisible thing is holding on to it... My impression is this has started since PS 2020, but not "100%" sure yet...
Here I've closed the main programs and nothing in services is looking huge either. Yet I remain at 57% on my RAM... :-o