Mac M2 Pro or M2 Studio Max for best Lightroom experience?

[Sco Dobes]

Greetings, I'm 85 photography/15 video using an original base model M1 Mac Mini with 16GB ram/1TB SSD, 8-core CPU/8-core GPU into an LG 5K display. This configuration has served me well and is light years better than my last 5.4K iMac. But now I'm noticing some slowdowns. For example, in LR on a large 1000+ image job (Canon R5 raw images) the preview renders in Library mode can be frustratingly slow. The thumbnails are there but they can be soft/fuzzy for 1 and up to 10 seconds before "blooming" in to sharp focus. This kills productivity during the image culling phase. Also, some of the new LR AI masking features are very slow.

Perhaps I'm lacking a "setting" in preferences (camera raw cache settings or GPU setting)? Otherwise, in light of this, I'm considering a hardware upgrade if this might improve things. I'm currently looking at the M2 Pro (base 10-core CPU/16-core GPU) and the M2 Studio Max (base base 12-core CPU/30-core GPU). Most likely either one with 32GB RAM and 1TB SSD. Configured that way both machines are $2200 with the advantage to the Studio with 2 more USB ports and MUCH better GPU.

So my question is, does anyone have experience to share with these models with LR? Is LR CPU or GPU intensive or both? RAM intensive? Because if it's not GPU intensive or RAM intensive then I might as well just get the base M2 Pro with 16GB RAM for a lot less and enjoy the better CPU (and GPU) and added ports the M2 Pro has over the original M1.

P.S. I know that it's rumored that Mac will be making an announcement about a new M4 Mini this fall (apparently skipping M3) and that I should probably wait until those details are revealed but from what I'm hearing the new M4 Mini will be physically smaller and have *fewer ports than the M2 Pro or Studio which is a deal-breaker for me.

[Jao vdL]

What are your settings in Preferences->performance when you select custom for the graphics processor? Is use GPU for export selected?

The limiting factor on your M1 mini is probably the 16 Gigs of memory. I recommend 32 GB for Apple silicon macs as the ideal amount that balances performance and price. 16 is just a bit too low but still reasonable with 8GB unworkable with high MP camera files. 

No clue if Apple will release a M4 mini soon. They are generally not so predictable and tend to 'forget' the mini line for a long time. It is true that the Pro and Max chips in any version are quite a bit faster than the base. The difference between single digit version upgrades are not so big. Less ig than the difference between Max and base.

[Sco Dobes]

Thank you for the reply Jao.  10-4 on the potential RAM issue.  I'll be sure to get at least 32GB in future purhases.

Regarding Prefs->Performance->GPU, it's funny you mention that because in addition to this post, I was looking for other answers / help and found your same tip about setting GPU in prefs.  Mine was on "auto" but I just selected Custom->Use GPU for image processing->Use GPU for export and I will see if that helps.  So based on your answer, can I infer that GPU processing power IS a factor with LR on-screen image processing and therefor the M2 Studio Max would be a better choice between it and the M2 Pro with lessor GPU cores? Thanks!

[Conrad_C]

Is LR CPU or GPU intensive or both? RAM intensive?

By @Sco Dobes

The answer is “yes” and “it depends” (I explain that below). Also, the answer changes over time as the developers find more ways to accelerate different areas of the application. For example, GPU acceleration was recently enabled for export, and more recently, the Apple Neural Engine was enabled to help speed up AI Denoise.

CPU: Single-core performance and having more CPU cores benefits overall operation and preview generation.

GPU: More GPU cores benefit the GPU-accelerated parts of Lightroom Classic, but currently, only some parts are GPU-accelerated such as the Develop module, AI features, AI Denoise and exporting (GPU acceleration saves the most time during large bulk exports).

Unified Memory: Having more helps everything, especially the GPU, but after you reach the amount you need (which for most people is between 24-64GB), paying for more makes no difference.

Unless the M4 is some kind of breakthrough (probably not), even if Apple announces something it might not be that much better for Lightroom Classic than the M2/M3. So the real benefit of an M4 announcement might be to push down prices on the M2/M3 models.

For many people who need a Mac desktop for Lightroom Classic, the base Mac Studio is a nice balance between price and performance.

OK, now for more details:

For example, in LR on a large 1000+ image job (Canon R5 raw images) the preview renders in Library mode can be frustratingly slow. The thumbnails are there but they can be soft/fuzzy for 1 and up to 10 seconds before "blooming" in to sharp focus…

Perhaps I'm lacking a "setting" in preferences (camera raw cache settings or GPU setting)?

By @Sco Dobes

Currently, preview generation depends totally on CPU performance. GPU and memory are not major factors. Also note that “previews” means viewing images outside of the Develop module. Inside the Develop module, the preview can use GPU acceleration, is always rendered from raw at the highest quality, and is cached in the Camera Raw cache, not the previews cache.

CPU performance for previews works out like this:

Faster single-core CPU speed is better, of course. But in the Apple Silicon range for Macs, single-core speed is roughly the same across the line. So getting an M2 Max or Ultra does not get you noticeably faster single-core speed than a base M2. To get more single-core speed, you move up to an M3.

More CPU cores can benefit previews, and this is where the upper Mac tiers help. The 12 CPU cores on an M2 Max (and the 24 CPU cores on the M2 Ultra) should be able to process more previews in parallel compared to an 8-core M2 mini, although it might not be 1:1 (having 1/3 more cores might be not quite 1/3 faster). But to make this happen, make sure Generate Previews in Parallel is enabled for Lightroom Classic, because if it’s disabled I think Lightroom Classic won’t apply all available CPU cores to preview generation.

Also, some of the new LR AI masking features are very slow.

By @Sco Dobes

Masking and AI masking depend heavily on GPU performance, which depends on the number of GPU cores and amount of available Unified Memory.

Your Mac mini has 8 GPU cores. Compared to that, the 30 GPU cores in an M2 Max will speed up anything that’s GPU accelerated, so there should be a noticeable improvement in general Develop performance and AI masking. The most directly observable improvement benefit is in AI Denoise, where doubling the GPU cores generally halves AI Denoise processing time.

The amount of Unified Memory affects GPU performance because the OS and GPU both draw memory from that pool. On a Mac with 8GB (and maybe 16GB), after the OS, Lightroom Classic, and other processes take the memory they need, there might be too little memory left for effective GPU acceleration. But above 24GB, there should be enough in many cases. I have 32GB and that works fine for my needs (24 megapixel frames with the occasional larger panorama). If budget allows, 64GB is nice to have when working with higher megapixel images, or if you want to keep several large images open in both Lightroom Classic and Photoshop at the same time.

[Sco Dobes]

Thank you very much for this detailed response Conrad.  It is apparently indeed a complex and apparently ever-changing answer with regard to CPU/GPU/unified memory and how they serve the software one is using. I must say, I am leaning to the Studio.  Now, just 32GB or 64 is what I have to ponder.