RawTherapee really slow (macOS)


I wanted to give RT (5.8) a try and installed it on my Mac. Sadly it is craaaazy slow. Updates on adjusting the exposure for example take almost a seconds. Same thing with scrolling through thumbnails. Pretty much unusable. The strange part is that I have seen people use RT on Macs in YouTube videos without that kind of lags.

Did I miss some thing to set up? Some kind of graphics acceleration?

I really don’t think my computer is the bottleneck:

  • Intel Core i7-7920HQ
  • 16 GB RAM
  • …and obviously I am running it from my PCIe SSD
  • macOS 10.15.1 (19B88) Catalina

Screen resolutions I tried (sorted by UI lag; slowest first):
1440x900 – absolutely sluggish
1024x640 – really slow
2880x1800 – fastest, still not usable

RawTherapee version:
Version: 5.8
Branch: 5.8
Commit: 9a9e0acbf
Commit date: 2020-02-04
Compiler: clang
Processor: generic x86
System: Apple
Bit depth: 64 bits
Gtkmm: V3.24.2
Lensfun: V0.3.95.0
Build type: release
Build flags: -Wno-deprecated-register -Wno-unused-command-line-argument -std=c++11 -std=c++11 -mtune=generic -Werror=unused-label -Werror=delete-incomplete -mmacosx-version-min=10.9 -flto -Wall -Wuninitialized -Wcast-qual -Wno-deprecated-declarations -Wno-unused-result -Xpreprocessor -fopenmp /opt/local/lib/libomp.dylib -I/opt/local/include -Werror=unknown-pragmas -O3 -DNDEBUG -ftree-vectorize
Link flags: -mtune=generic -headerpad_max_install_names -flto
OpenMP support: ON
MMAP support: ON

What is the native resolution of your monitor?


Well I can say it does fit the pattern of macs working best in native resolution in RT. Please stay tuned for when we have potential fixes to test.

Thanks a lot!