2
Replies
I don’t have a comprehensive answer, but my quick opinion is that it might be related to the 8GB of Unified Memory in your Mac. In the posted Lightroom Classic System Requirements, 8GB is the Minimum memory amount, not the Recommended amount, and this has been true for several years already. The Recommended level is 16GB. If the Mac is only reaching the Mimimum memory amount, then “mimimum” performance might be expected.
With the last several versions of Lightroom Classic, it seems like 16GB (what Adobe says is “Recommended”) is where good sustained overall performance can be expected. I personally think it’s good to aim for at least 24GB.
Adobe is not optimising the software for M processors I am just frustrated about this. It is unacceptable..
By @Dăuceanu
I do not think that statement is true. Why? I use a Mac older than yours…an M1 Pro MacBook Pro. And yet I think Lightroom Classic performance is just fine. Not spectacular; when I use a lot of masks there is some lag that I think would go away on an M3/M4. But my M1 Pro performs well enough that I don’t think it’s time to buy a new Mac yet. And it is much faster than my previous Intel MacBook Pro.
Maybe my M1 runs well because it has 32GB of Unified Memory.
Here is why that might be important. At 8GB, you have a couple GB for macOS, leaving maybe 6GB. Then Lightroom Classic wants a few GB of that. In recent versions, more Lightroom Classic features have become GPU-accelerated, which is great because GPU acceleration can get things done faster with less power (and therefore less heat and less battery consumption) than making the CPU do it. GPU performance is also what has made AI features, such as people masking, practical to do.
However, effective GPU acceleration depends on having enough memory for the GPU, and Apple Silicon Mac take graphics memory from Unified Memory. If your Mac has 8GB, and macOS is taking 2 or 3GB, and your applications take much of the rest, there aren’t many GB left for GPU acceleration to work well. This might bottleneck all features depending on GPU acceleration for top performance.
Keep in mind that the typical discrete GPU on a PC is now 8GB…just for the GPU. If you have a Mac with only 8GB of Unified Memory, there is no way for that Mac to assign as much memory to the GPU as a common PC graphics card. There just isn’t enough memory left over, so GPU acceleration could be bottlenecked on an 8GB Mac.
But if your Mac has 24GB and up, now there is enough memory for macOS, Lightroom Classic, and GPU acceleration to all get what they need. The reason I ordered my Mac with 32GB is to also have memory for other apps to also stay open and not be bottlenecked, like Photoshop. This doesn’t mean more memory is always better; beyond 32–48GB there are diminishing returns for photographers; although you can now order a MacBook Pro with 128GB of Unified Memory you won’t need all that.
The sweet spot today for Lightroom Classic performance today is probably 24–32GB of Unified Memory, although 16GB is probably fine for more basic editing or if you don’t keep a lot of other applications open.
Although I am not sure if a memory bottleneck is the full explanation, you will probably find that 8GB is below what many in this forum would consider acceptable for any serious work in the current/recent versions of Lightroom Classic. This may be especially true in macOS 15, because the addition of Apple Intelligence is thought to be why Apple stopped selling 8GB Macs: Adding AI features increases memory requirements. All current new Macs start at 16GB.
Also, if you don’t think it’s optimized for Apple Silicon M processors, try a PC laptop. Many tests you can find online have shown that, actually, the Apple M processors tend to run Lightroom Classic very competitively compared to PCs, and the Mac laptops often complete the Lightroom Classic benchmarks faster while using less power. So if it isn’t optimized for Apple Silicon, optimization for Intel must be even worse…?
AdChoices