Here’s the salient parts of the console output:
[dev] took 1.264 secs (0.987 CPU) to load the image.
[export] creating pixelpipe took 0.229 secs (0.281 CPU)
[pixelpipe_process] [export] using device -1
pixelpipe cacheline 0 used 0 by 18446744073709551615
pixelpipe cacheline 1 used 0 by 18446744073709551615
cache hit rate so far: -nan
[dev_pixelpipe] took 0.000 secs (0.000 CPU) initing base buffer [export]
[dev_pixelpipe] took 0.046 secs (0.030 CPU) processed `raw black/white point' on CPU, blended on CPU [export]
[dev_pixelpipe] took 0.043 secs (0.035 CPU) processed `white balance' on CPU, blended on CPU [export]
[dev_pixelpipe] took 0.010 secs (0.020 CPU) processed `highlight reconstruction' on CPU, blended on CPU [export]
[default_process_tiling_roi] use tiling on module 'demosaic' for image with full input size 5240 x 3912
[default_process_tiling_roi] (4 x 4) tiles with max dimensions 1753 x 1309
....
[dev_pixelpipe] took 3.599 secs (5.655 CPU) processed `demosaic' on CPU with tiling, blended on CPU [export]
[default_process_tiling_ptp] no need to use tiling for module 'basecurve' as no real memory saving to be expected
[default_process_tiling_ptp] fall back to standard processing for module 'basecurve'
[dev_pixelpipe] took 0.240 secs (0.272 CPU) processed `base curve' on CPU with tiling, blended on CPU [export]
[default_process_tiling_ptp] no need to use tiling for module 'colorin' as no real memory saving to be expected
[default_process_tiling_ptp] fall back to standard processing for module 'colorin'
[dev_pixelpipe] took 0.199 secs (0.337 CPU) processed `input color profile' on CPU with tiling, blended on CPU [export]
[default_process_tiling_ptp] use tiling on module 'atrous' for image with full size 5000 x 3733
[default_process_tiling_ptp] (24 x 18) tiles with max dimensions 723 x 723 and overlap 256
.....
[dev_pixelpipe] took 0.697 secs (1.087 CPU) processed `sharpen' on CPU with tiling, blended on CPU [export]
[default_process_tiling_ptp] no need to use tiling for module 'colorout' as no real memory saving to be expected
[default_process_tiling_ptp] fall back to standard processing for module 'colorout'
[dev_pixelpipe] took 0.373 secs (0.691 CPU) processed `output color profile' on CPU with tiling, blended on CPU [export]
[dev_pixelpipe] took 0.120 secs (0.217 CPU) processed `gamma' on CPU, blended on CPU [export]
[dev_process_export] pixel pipeline processing took 461.493 secs (653.987 CPU)
[export_job] exported to `/media/iullah/Seagate Backup Plus Drive/Photography/2018/20180110/darktable_exported/P1104697_01.jpg'
Here’s what initially popped when I opened darktable with the suggested options:
iullah@iullah-Peppy:~$ darktable -d perf -d dev -d opencl
[opencl_init] opencl related configuration options:
[opencl_init]
[opencl_init] opencl: 1
[opencl_init] opencl_library: ''
[opencl_init] opencl_memory_requirement: 768
[opencl_init] opencl_memory_headroom: 300
[opencl_init] opencl_device_priority: '*/!0,*/*/*'
[opencl_init] opencl_mandatory_timeout: 200
[opencl_init] opencl_size_roundup: 16
[opencl_init] opencl_async_pixelpipe: 0
[opencl_init] opencl_synch_cache: 0
[opencl_init] opencl_number_event_handles: 25
[opencl_init] opencl_micro_nap: 1000
[opencl_init] opencl_use_pinned_memory: 0
[opencl_init] opencl_use_cpu_devices: 0
[opencl_init] opencl_avoid_atomics: 0
[opencl_init]
[opencl_init] could not find opencl runtime library 'libOpenCL'
[opencl_init] could not find opencl runtime library 'libOpenCL.so'
[opencl_init] found opencl runtime library 'libOpenCL.so.1'
[opencl_init] opencl library 'libOpenCL.so.1' found on your system and loaded
[opencl_init] could not get platforms: -1001
[opencl_init] FINALLY: opencl is NOT AVAILABLE on this system.
[opencl_init] initial status of opencl enabled flag is OFF.