I can’t find it any more, but I recall a rather significant (not 1-5%, but rather 20-40%) speed-up on the CPU-only path when I compared the Ubuntu-packaged version with the self-compiled one.
A quick comparison now, with the daily AppImage vs locally-compiled. Exporting a single image from my old Panasonic LX7 (10 MPx) with typical processing (filmic/sigmoid, local contrast, diffuse or sharpen), after clearing .cache/darktable and starting the application, waiting for all thumbnails to be built:
AppImage / local, without OpenCL: 17.5970 s / 10.9683 s (160% or 62%, depending on from which side you look at it)
AppImage / local, with OpenCL: 3.5331 s / 3.3196 s (106% or 94%)
CPU: Ryzen 5 5600, GPU: NVidia 1060
Not to depreciate Bill’s work, I think he basically builds whatever is on master come Sunday:
What I mean is they are not ‘curated’ or ‘higher quality’ or ‘contain hand-picked changes’. I appreciate his work, and have long used his builds on the Windows laptop I sometimes use to answer Windows-related questions or to test Windows-related issues. Having a reliable source of builds in case the GitHub CI build breaks is valuable.
In this particular case, there was a bug fixed after the weekly build was published. You were affected by that bug: it was the cause why darktable -d opencl crashed without printing an error message to the console.