Lightroom Classic on Apple Silicon Macs

Now that Apple is shipping Mac computers based on M1 Apple Silicon processors, test results are starting to appear, and some of them include Lightroom Classic. I spend a lot of time in Lightroom Classic, so I’m interested in how well it’s running on Apple Silicon Macs. This article lists links to some of those tests.

General compatibility with Apple Silicon

The Adobe support article Lightroom Classic and Big Sur | macOS 11 has an Apple Silicon compatibility section that says:

“There are no known issues specific to running Lightoom Classic 10.x under Rosetta 2 emulation mode on Apple devices with M1 processors running macOS BigSur (version 11).” — Adobe

That’s good, because Lightroom Classic is not yet available as a native Apple Silicon application — Adobe says they’re working on it for a 2021 release. The current version, Lightroom Classic 10 for Intel Macs, is what’s used in the tests below.

“The team is working on a native version of Lightroom Classic for Apple Silicon, and it will be released next year. We’re also committed to continuing support for Intel-based Macs.” — Adobe

General performance tests

The Lightroom Classic tests on Apple Silicon so far have been limited, quick tests that are usually part of a larger overall test involving a range of applications, so they don’t answer all of the questions we might have about performance and stability. However, the general pattern is encouraging.

The website Bare Feats, which has reported on Mac performance for many years, ran a series of tests in its article M1 MacBook Pro versus Intel MacBook Pro, including one where 12 images were enhanced in Lightroom Classic (although it doesn’t say how they were “enhanced”). The Intel 13-inch MacBook Pro processed the 12 images in 180 seconds, while the new M1 Apple Silicon 13″ MacBook Pro processed them in just 41 seconds.

The YouTube channel MaxTech also regularly tests the performance of new Macs. In their video M1 MacBook PRO vs Intel MacBook PRO: ULTIMATE Comparison, fifty 42-megapixel raw files are exported from Lightroom Classic in 4 minutes 8 seconds on the Intel 13″ MacBook Pro, while the M1 13″ MacBook Pro finished in 2 minutes 53 seconds. The Lightroom Classic test starts at around 18:24.

Those times are consistent with tests run using other applications across the M1 MacBook Air, MacBook Pro, and Mac mini. In general, the M1 Macs appear capable of running Intel applications faster in translation than they run natively on comparable Intel Macs.

The YouTube channel ArtIsRight also ran tests of Lightroom Classic, using 100 Nikon D850 images (45 megapixels each) on an M1 Mac mini. Compared to the much more expensive Intel 16″ MacBook Pro, the M1 was slower rendering 1:1 previews, but faster rendering exports. In the video below, the Lightroom Classic test starts at 3:38.

ArtIsRight also ran a test of display calibration, both software profiling and true hardware calibration. Those tests start at 14:51. Calibration and profiling were not completely successful, which is a concern if you work depends on accurate color reproduction. It looks like software updates will be needed here, or you should continue to use an Intel Mac for now.

Notes on general performance

The main difference between the Apple Silicon Macs appears to be how long they can sustain top performance. According to reports, after about 9 minutes at maximum load the MacBook Air processor slows itself to let the processor cool down, but the MacBook Pro and Mac mini continue to sustain high performance because they have active cooling (a fan).

It is not just that M1 is performing much faster than Intel. It’s doing it using less power — it is capable of more power per watt. Using less power has two benefits: Heat builds up more slowly, allowing high performance for a longer time. Cooling fans take longer to kick in, and when they do, they’re quieter. And the same battery capacity lasts for more hours. Even though the M1 Mac had to run Lightroom Classic through the Rosetta translator, with just 8GB of Unified Memory (CPU and graphics use the same single memory pool), it still beat the Intel Mac by a large margin, at lower operating temperatures.

Other tests have showed that the graphics performance of these first M1 processors is far ahead of Intel integrated graphics, approaching the range of discrete graphics.

The M1 Apple Silicon processor looks very promising. And remember, in the Lightroom Classic tests above, Lightroom Classic is running much faster on the M1 Macs even though it is not yet optimized for the M1 processor. When Adobe releases the native Apple Silicon version of Lightroom Classic in 2021, the performance advantage of M1 Apple Silicon over Intel should be even more dramatic — definitely something to look forward to.

Memory (RAM) tests

Many have been interested in a RAM test, because early adopters of M1 Macs have noticed that having “only” 8GB RAM appears to let them tackle bigger jobs and larger files rather smoothly, without the performance degradation seen on a comparable Intel-based computer with 8GB RAM.

Some videos run simple tests of a single application on the same M1 Mac model under 8GB and 16GB RAM, but many of those tests are not turning up significant differences in performance. MaxTech made one of those videos, but by popular demand they later made the follow-up video below that is more of a stress test, loading up a number of other applications first to occupy RAM and then testing Lightroom Classic. Finally, after pushing the machines harder in this way, real performance differences start to emerge. In the video below, the Lightroom Classic RAM test starts at 12:37. Again, at this time Lightroom Classic is not yet optimized for Apple Silicon.

8GB RAM can be a real limitation on Intel-based computers, but on an Apple Silicon Mac you have to load down the machine much more to see a performance penalty for having only 8GB RAM. It looks like the 8GB RAM M1 Macs may be surprisingly acceptable for many workloads.

Memory-intensive professional workloads (for example, constantly having multiple applications open with large documents) should still benefit from upgrading to 16GB RAM. You have to do that when you buy the computer, because it is not possible to replace any component inside an M1 Mac.

Ready to go?

Should you should order an M1 Mac right away for use with Lightroom Classic? That depends on whether everything you need for your work is properly supported on the new processor as well as on macOS 11 Big Sur, which is required to run an M1 Mac. Although Adobe says there are no known issues at this time, it may be worth waiting to see if any more problems turn up as more people use Lightroom Classic on M1 Macs in production, or wait until applications such as Lightroom Classic and Photoshop are fully optimized for M1.

I will at least wait until it’s clearer that everything in my capture-to-print workflow will work properly on M1 Macs and Big Sur, including display calibration software, photo editing applications, and printer drivers.

This is also just the first generation of Apple Silicon Macs, shipped in the same enclosures as before. More powerful Apple Silicon processors are inevitably coming to help Apple replace the upper levels of the Mac product line. Many are assuming that those might arrive in 2021 with fewer technical limitations and with the next major redesign of Mac enclosures. I’m going to see if I can wait for that.

2 comments

  1. The biggest question to the “12 images enhancement” test is what they actually did? Is it because the interface was responsive? Or it is time with export? Or just export?

    1. There isn’t much detail about the Lightroom Classic test on the Bare Feats web page site. But Rob’s on Twitter so it’s possible to ask for more specifics. The video is more helpful because you can see what they were doing.

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