upgrade advice: photoshop benefits from apple pro or max chip with large 16bit files at 100GB size?

[pets]

hi

may i ask the developers please, if its 2024/25 still the case, that photoshop code

benefits from single core performance, instead of multicore, specifically in my case, handling large .psb files in 16bit only, throughout the years. (panorama layer files at 300dpi, 80x80inch, with 100-200 layers, 50-150 GB on disc)

so, opt for m4 "max" rather than m4 "pro" ?

currently i use a mbp m1 max with 4TB ssd and separate 2TB OWC ssd external, TB4, as empty scratch disc - and mac studio ultra with 4TB ssd and 128GB RAM. i am satisfied working with these 2 macs on my files, though it tends to be laggy and not realtime working anymore. (with above mentioned files only, smaller psb. files at 5GB or 10GB filesize are totally fast)

i noticed, when reducing the history steps to 4 instead of 20, there is less lag, also my ram is mostly full at 100GB, and its swapping RAM to ssd disc (OWC at 1-2GB/sec) so one developer told me, photoshop code is limited to write to disc at maximum 1-2GB/s. (photoshop psb. file compression is off)

thanks for advice.

[D Fosse]

With these file sizes, it's almost entirely down to the speed of your scratch disk. That's where the heavy lifting is. The amount of RAM is almost irrelevant, it's just a drop in the ocean of total memory I/O.

So for this, I'd want PCIe generation 4.0 NVMe for the scratch disk, and at least 5 TB available. I'm not familiar with Apple's component specs, but PCIe 4.0 is about twice as fast as PCIe 3.0. That matters. I'd above all try to avoid having scratch go to any sort of external storage. That will slow things down enormously.

The general consensus now is that you get the best scratch performance by having it on the system drive.

The other critical component is the GPU, but with Apple you don't have a lot of choice, except as good as you can afford. Not all functions leverage the GPU, but for those that do - and with these file sizes - you probably want the high end.

Oh, and yes, definitely keep all compression off.

[pets]

thanks, i know what you could mean,

The general consensus now is that you get the best scratch performance by having it on the system drive.

The other critical component is the GPU, but with Apple you don't have a lot of choice, except as good as you can afford.

going more into detail:

- currently i use a thunderbolt 4 (pcie 3) scratch disc, with an always free 2TB space. i am heading for thunderbolt 5 soon. (= pcie 4)

- scratch disc on system drive is disputable, see "adobe photoshop optimize performance help document" (which may be outdated, as per date i ve been reading it). they recommend, the system on one drive and the empty scratch disc on another internal drive to avoid read/write conflicts/bottleneck. though every pro photoshop user handles this differently. there is no official consensus? i wonder, as its very important.

- GPU: as a mac user, you can opt for the most expensive "m3 or 4 max/ultra GPU" currently. i doubt, that someone knows details about in-depth photoshop usage of these GPU's, though developers could report, as they might improve photoshop code over the years? i know, they dont read our forums, though good luck, if anyone else has internal knowledge.

- i am using the "m2 ultra" GPU with latest photoshop and can compare with my "m1 max" gpu. i dont notice significant differences though. 🙂 

[D Fosse]

the system on one drive and the empty scratch disc on another internal drive to avoid read/write conflicts/bottleneck.

By @pets

That's outdated. That applied to spinning hard drives with a read/write head that could only be in one place at a time. It doesn't apply to solid state drives.

That said, you probably won't notice very much difference in practice, between system drive or separate drive, all else being equal.

What's interesting is that NVMes are so fast now, that the amount of RAM is no longer very important as long as it fulfils its basic cache function. The scratch disk is for all practical purposes as fast as RAM. I'm sure there are measurable differences, but the point is that you don't sit around waiting for it.

[Trevor.Dennis]

I am mostly a Windows user, but do have an M2 MacBook Pro.  I am wondering what Mac systems are like for custom builds nowadays, because I thought they were not great in that respect.  I would be looking at system specifically designed with the workloads you described, and I would only be comfortable doing that with a Windows system.  

What I am also wondering is do you really need this to all be in the one document?   Bert Monroy is the person best known for mega projects with his Times Square, and Amsterdam projects.  

https://www.bertmonroy.com/timessquare/timessquare.html

That project used thousands of layers and hundreds of files, with each element created in separate files and a flatterned version added to the master document.  It would have been impossible to do it any other way.  Could you addopt a similar workflow? 

Something I do when projects are getting out of hand is to make a complicated image element a Smart Object. Open the Smart  Object in a new window to edit, and save it aas a layered .PSB file from that new window.  The original SO is then rasterized/merged to a single layer.  Note, I am suspicious of the way Photoshop handles (i.e. hangs on to) memory in these situations.  You can monitor your scratch Photoshop Temp files, but I don't know for sure how Smart Objects are stored, so it can be advisable to save, close, and reopen Photoshop to fully purge a clogged up system when working with mega files.

It's astonishing how storage continues to improve.  My current system was built in April last year, and the main storage components are a pair of Samsung 2tb 980 PRO, but they are already well down today's bencharmarks.

I stuck with 64Gb RAM because it's what my last system had, and Photoshop never came close to using its alocated memory.  It creates some scary large Photoshop temp files though, so like Dag said, that's going to be the bottleneck with mega-projects.  I still wouldn't want to do this with a Mac System though.

[pets]

thanks for your hint, i know these times square panoramic images by bert,

and i already work like this since many years. otherwise it would not be possible.

usually have 10-20 smart objects at 16bit sitting in my main document with background only, at 8bit.

its still a 100 GB PS document. but with 128GB RAM, a 4TB internal apple SSD, and a large scratch disc (SSD) its enjoyable working, though sometimes no real time working anymore. (2-3 seconds lag for each operation)