Photoshop is running too slow

Do you mean PS is processing the images slowly, or is it just slow to open?

I had the slow-open experience with Photoshop Elements on a MacBook Pro and the issue was not RAM. Most entry-level Macs including 21.5-inch iMac from 2012 through 2019 shipped with slow 5400 rpm hard drives rated at only half the data transfer potential of the logic board. Most are slower than drives in entry-level 2010 and 2011 iMacs.

Here are data on how adding RAM and then adding an solid-state drive affected the load time issue, taken from my MacBook Pro also fittd with an i5 processor:

Base system as shipped:

4GB RAM and slow SATA 3GBps 5400rpm hard drive: Office and Photoshop Elements took 15-18 seconds to be ready to use.

First upgrade, doubling the RAM:

8GB RAM and slow SATA 3GBps 5400rpm hard drive: Office and Photoshop Elements took 15-18 seconds to be ready to use.

Second upgrade, inexpensive solid-state drive (SSD)

8GB RAM and fast SATA 6GBps SSD: Office and Photoshop Elements take under 4 seconds to be ready to use.

RAM in your iMac model is not user-upgradeable. Apple will not do it nor will some Apple Authorized Service Providers. It is a major teardown; almost everything inside has to come out. And RAM won't fix a slow-load situation.

if it is your hard drive (posting an EtreCheck report will show actual drive performance), the best action is to sell or trade in your current computer for one with more RAM and an SSD, preferable a 27-incher. IF that ins not to be, the is an workaround. Obtain a USB3 external drive enclosure and instel in it a 6GB/sec solid-state drive. Connect the external drive, clone the entire internal disk to the external, the use System Preferences > Startup Disk to se the external as the boot partition.

If you do the EtreCheck report we can se your current drive performance and quickly tell if that option will improve matters.

When you post the report, remember that the forums' character limit won't permit the entire report to be posted in one go unless you use the "Additional Text" option in the toolbar:

Minimum specs for Adobe Photoshop,

https://helpx.adobe.com/photoshop/system-requirements.html

Your computer just barely meets the specs for PS to run on your system. Do you know the rest of your computer’s specs/components? What type of storage drive — SSD or Fusion? Which graphics/video card does it have? What OS is your computer running?

Depending on the model computer your have, you may not be able to update your iMac much, if at all. Some of the components are soldered to the board and are not really user replaceable.

Got it! Thank you. That worked quite well.

As suspected, you have the 5400 rpm, 3GB/sec hard drive. Your computer has a 6GB/sec hard drive interface. Apple was saving money.

Drives:

disk0 - APPLE HDD HTS541010A9E632 1.00 TB (Mechanical - 5400 RPM)

Internal SATA 3 Gigabit Serial ATA

This doesn't help:

System Software:

macOS High Sierra 10.13.6 (17G14019)

Time since boot: About 21 days

When you have a slow HD and don't have a lot of RAM, restarting every 3-5 days will help prevent this:

Virtual Memory Information:

Physical RAM: 8 GB

Free RAM: 20 MB

Used RAM: 6.79 GB

Cached files: 1.19 GB

Available RAM: 1.21 GB

Swap Used: 4.61 GB <<

That much memory in Swap is seldom good and forces the computer to write RAM to the hard drive. And your hard drive is gasping for air:

Performance:

System Load: 3.82 (1 min ago) 3.38 (5 min ago) 3.24 (15 min ago)

Nominal I/O speed: 0.12 MB/s

File system: 99.45 seconds

Write speed: 38 MB/s

Read speed: 60 MB/s

Write/reads for that drive model, even though it is slow, should be in the 60-80MB/sec range.

Zoom was using about 25% of your CPU cycles. I cannot tell if you were on a conference at the time of the test or Zoom was open in the background. If the latter, save resources by quitting it when not using it.

Fortunately, I do not see the "usual suspects" of unneeded software. Good Job.

The external SSD solution will help a lot with slow booting and app launches and, considering how much Adobe CC accesses the disk, Photoshop performance. The drive must be USB3 and the SSD inside must be rated 6Gb/sec to see the full benefit. Your current drive read/writes were no higher than 60MB/sec. The external SSD with the specs I posted will do 400MB/sec.

Bottom line is that, for Adobe CC, this computer is bare minimum. The external SSD thing is a workaround at best. Upgrading its RAM is neither a feasible at-home project for most users, nor cost effective with profession labor charges.

If you decide to replace, get the 27-inch that allows users to install RAM up to 128GB whenever you wish, and get the biggest factory-installed SSD you can afford. I have the factory SSD in my 2017 27" and look at the difference in EtreCheck drive scores compared to what yours reported:

Apple 1TB SSD:

Performance:

    System Load: 1.66 (1 min ago) 1.42 (5 min ago) 1.31 (15 min ago)

    Nominal I/O speed: 0.23 MB/s

    File system: 20.35 seconds

    Write speed:  2156 MB/s

    Read speed:  2863 MB/s

FWIW, my experience with Photoshop is that anything less than

16GB on any Mac is going to be dog slow because of memory

swapping and the fact that Photoshop will gobble up all the

memory it can.

I don't do Google Drive and it requires an account to view. Can you try another site? Many others have uploaded the reports to Pastebin and it does not require a login like the Google apps.

Apple provides no way to rectify it. :(