My darktable instance (4.0.1 latest from git) does recognize my GPU, but doesn’t utilize it. It has been utilized earlier, I don’t recall what was the latest 3.9 version that had it utilized, but 3.9 from late May was visibly slower. I was on holidays the whole June, and didn’t touch darktable during that period. When I started to process my photos from the trip, I noticed the lagginess, and started to analyze it. My first step was to update to the latest version and run dt from the command line with debugging options.
Output from -d opencl is:
[opencl_init] opencl related configuration options:
[opencl_init] opencl: ON
[opencl_init] opencl_scheduling_profile: 'default'
[opencl_init] opencl_library: 'default path'
[opencl_init] opencl_device_priority: '0,*/!0,*/0,*/0,*'
[opencl_init] opencl_mandatory_timeout: 2000
[opencl_init] opencl_synch_cache: false
[opencl_init] opencl library 'OpenCL.dll' found on your system and loaded
[opencl_init] found 2 platforms
[opencl_init] found 2 devices
[dt_opencl_device_init]
DEVICE: 0: 'NVIDIA T500'
CANONICAL NAME: nvidiat500
PLATFORM NAME & VENDOR: NVIDIA CUDA, NVIDIA Corporation
DRIVER VERSION: 516.59
DEVICE VERSION: OpenCL 3.0 CUDA, SM_20 SUPPORT
DEVICE_TYPE: GPU
GLOBAL MEM SIZE: 4096 MB
MAX MEM ALLOC: 1024 MB
MAX IMAGE SIZE: 32768 x 32768
MAX WORK GROUP SIZE: 1024
MAX WORK ITEM DIMENSIONS: 3
MAX WORK ITEM SIZES: [ 1024 1024 64 ]
ASYNC PIXELPIPE: NO
PINNED MEMORY TRANSFER: YES
MEMORY TUNING: YES
FORCED HEADROOM: 400
AVOID ATOMICS: NO
MICRO NAP: 250
ROUNDUP WIDTH: 16
ROUNDUP HEIGHT: 16
CHECK EVENT HANDLES: 128
PERFORMANCE: 0.359245 (CPU 0.108690)
DEFAULT DEVICE: NO
KERNEL DIRECTORY: C:\Program Files\darktable-dev\share\darktable\kernels
CL COMPILER OPTION: -cl-fast-relaxed-math
KERNEL LOADING TIME: 0.0317 sec
[dt_opencl_device_init]
DEVICE: 1: 'Intel(R) Iris(R) Xe Graphics'
PLATFORM NAME & VENDOR: Intel(R) OpenCL HD Graphics, Intel(R) Corporation
DRIVER VERSION: 30.0.101.1404
DEVICE VERSION: OpenCL 3.0 NEO
DEVICE_TYPE: GPU
GLOBAL MEM SIZE: 12988 MB
MAX MEM ALLOC: 4096 MB
MAX IMAGE SIZE: 16384 x 16384
MAX WORK GROUP SIZE: 256
MAX WORK ITEM DIMENSIONS: 3
MAX WORK ITEM SIZES: [ 256 256 256 ]
ASYNC PIXELPIPE: NO
PINNED MEMORY TRANSFER: YES
MEMORY TUNING: YES
FORCED HEADROOM: 400
AVOID ATOMICS: NO
MICRO NAP: 250
ROUNDUP WIDTH: 16
ROUNDUP HEIGHT: 16
CHECK EVENT HANDLES: 128
PERFORMANCE: 0.000000 (CPU 0.108690)
DEFAULT DEVICE: NO
*** marked as disabled ***
[opencl_init] OpenCL successfully initialized.
[opencl_init] here are the internal numbers and names of OpenCL devices available to darktable:
[opencl_init] 0 'NVIDIA T500'
[opencl_init] FINALLY: opencl is AVAILABLE on this system.
[opencl_init] initial status of opencl enabled flag is ON.
[dt_opencl_update_priorities] these are your device priorities:
[dt_opencl_update_priorities] image preview export thumbs preview2
[dt_opencl_update_priorities] 0 -1 0 0 -1
[dt_opencl_update_priorities] show if opencl use is mandatory for a given pixelpipe:
[dt_opencl_update_priorities] image preview export thumbs preview2
[dt_opencl_update_priorities] 0 0 0 0 0
[opencl_synchronization_timeout] synchronization timeout set to 200
[opencl_summary_statistics] device 'NVIDIA T500' (0): NOT utilized
