RawTherapee 5.8 is running very slow on Mac OS Catalina with the default monitor profile enabled. Switching the monitor profile to sRGB IEC61966-2.1 immediately improves performance. Just about everything gets faster - panning around an image, scrolling through thumbnails, scrolling panels, dragging sliders, processing. All of these are very laggy with the default ‘Colour LCD’ profile selected.
I have been working mainly with Canon S95 raw files, but it’s the same with all files I have tried.
So there seems to be some sort of bottleneck when using the Colour LCD profile. Switching to sRGB sorts out the performance, but clearly it’s not a solution, because all the colours change!
Macbook Pro 13 inch 2017
Intel Iris Plus Graphics 640 1536MB (2560x1600)
Commit date: 2020-02-04
Compiler: clang 188.8.131.5200033
Processor: generic x86
Bit depth: 64 bits
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