I updated my MacBook Air M3 to macOS 26.5 today. When I started darktable, about five notification bars slid up from the bottom of the screen, including some messages related to OpenCL. They disappeared too quickly to read.
What I can say for sure is that darktable feels noticeably more performant now. With several demanding modules active, the processing speed is significantly better than before.
Has anyone else noticed this? I’m curious what might have changed in macOS to cause such a big performance boost.
So could it be that Apple somehow rewired or optimized the OpenCL to Metal translation layer in macOS 26.5? And did they potentially update the OpenCL framework itself so that it now exposes extended functionality to DT? That would explain the notifications in DT during the first startup after the update.
The problem with this approach (kicking the can down the road) is that it generally fires back. I’ve experienced it in workplaces where, for example, whoever raises the issue of having these deprecation warnings never dealt or some legacy dependencies which are bound to become a liability, and so on, is shrugged off as a problem maker.
“Our priority is to deliver”, “we don’t have the bandwidth right now”, “new ways of doing things aren’t necessary better” and other platitudes. Until it comes the moment where things break in production, or a painful migration is inevitable and must be done in a tight timeframe, which brings hasty solutions and multiple bugs which need to be fixed in subsequent rapid “point” releases and never look good for the team.
Anyway, I’m going way off the tangent here… I’m just taking note that if (when) Apple decides to pull the plug on OpenCL, darktable might stop working or it might need some workaround. I can always revert to Linux.
But we don’t have any official statement, have we? One thing that I dislike of these proprietary systems is that their release notes are always so hazy, scant and difficult to retrieve.
I haven’t noticed any perceivable improvement with 26.5. For what I know, OpenCL could be underusing the latest Silicon chips and performance could be much better with the Metal API.
Not that I’m complaining or making a request, mind you, before reading this thread I hadn’t paid attention to which library is used for the Macs.
Is there a way of logging these notifications somehow?
Interesting. I’m still amazed at how much smoother DT runs on my Mac now. I checked the developer changelog for the macOS 26.5 release, and yes, it’s definitely pretty sparse. Since Apple deprecated OpenCL, they probably wouldn’t mention any related changes anyway.
I would hardly notice any improvements unless I did some controlled benchmarks. I started using darktable only a few months ago so and my wallet is still crying for buying a M4 Max last year so… it’s never been slow to begin with. But I definitely notice a difference with the old Thinkpad which doesn’t have a beefy GPU to rely upon.
If I find some time I’d like to investigate if the migration to the Metal layer is difficult or feasible. To be honest I have no experience with graphics or GPU programming.
that isn’t as simple as it sounds - at least on m1max the metal variants are drastically slower (usually a performance boost by about 40% can be expected)
So it seems it needs more changes to make use of the different memory handling options on arm processors …
So don’t hold your breath…
Just to confirm. I’m on 26.5 with a Mac Studio M2 Max and darktable is faster in the last nightly build I downloaded. I hadn’t attributed the speed improvement to 26.5 until reading this thread. For an upgrade that otherwise had no other new features, a speed boost in darktable is welcome.
I have read that PR, yes. I see that it triggered a wider discussion about long term plans, whether to rewrite at least some modules using Metal for MacOS, whether to ditch OpenCL altogether some time in the future and use Vulkan (which on MacOS needs another layer, MoltenVK, on top of Metal…) etc.
When you say “no other new features”, are you referring specifically to the last nightly build compared with the previous one or the upcoming release in general?
