Running Photoshop 2026 on a 2017 Mac...

It depends a lot on the kind of editing you do. 

If you mostly edit single images, and the edits aren’t too intense, such as some color and tonal adjustment layers and some cropping (the traditional edits), a new Mac might not seem all that much faster in Photoshop because your model has above average specs for an Intel Mac. You could keep going with your current Mac for a while. But keep in mind that if macOS 15 is the last macOS version it can run, it will probably lose support for Apple software updates in 2027 because Apple only supports updates for the last three major versions of macOS. This in turn will limit how many more Photoshop upgrades will support that Mac because like Apple, Adobe offers software updates for only the last three major versions of macOS. 

The more you edit very large images (any combination of high number of megapixels, high bit depths, and many layers and Smart Objects), or the more you want to do raw-level editing in bulk (such as using Camera Raw and Bridge together), the more you’ll see a significant speed improvement in a new Mac.

And then, looking toward the future, the more you’re interested in the latest AI features, the more a new Mac will benefit you. AI features that are processed on your computer instead of the cloud, such as many of the great new features in Adobe Camera Raw and Lightroom, really benefit from the faster GPUs in the latest Apple Silicon Macs.

​@mas1571 Upgrading as in getting a new MAC M5? Yeah, you would definitely see a mondo difference in working with your files. Get as much RAM as possible because AI is just getting bigger and better, and likely will be a RAM pig one day!  9 years is a fairly decent run. I am trying to hold off on the M6 myself making that my last MacBook Pro I will ever use...but may buy the MacBook Neo for my kid (and me!). My work uses the M4 Studio, and it’s amazing. I sometimes don’t even bring my MacBook Pro 2013 in!

It’s hard to quantify the actual speed/efficient improvement, because so much depends on what you intend to be doing with Photoshop.
From your CPU spec, it looks like you’re running an iMac Pro - 8 core machine, with a Radeon Vega Pro 56 GPU. 
Per your specs, this SHOULD theoretically work, but I’ve seen a lot of people complaining about performance on Intel based Macs, nowadays. A couple of years ago, I wan’t pleased on my Intel machine, and I am now getting a little frustrated at times, with my M1 Mac Studio MAX. And that’s only because my patience is longer than my pocketbook.😉

There’s an old discussion about your model with Adobe Media Encoder here: 

 - from 5 years ago. 
Of course, AME usually needs much more than Photoshop does, but nowadays, you’ll find that Photoshop, with a lot of it’s filter work, the AI, and such, it needs much more than it did at the time. 

I know for sure, you won’t get to use quite a few of the filters with your model - but of course, you may not need them.

I’d really suggest trying to install it on your current machine. With your subscription, you can install it WITHOUT uninstalling your current version. If it gives you a hassle with what you want to do, that’ll be your answer. Otherwise, you can stick with the older machine, until it does.

It’s SO hard to futureproof, nowadays. Your machine was KILLER when you got it, but computer time moves so fast….🙁