I get CPU versus GPU result deviations for almost all tests in darktable git master repo src/tests/integration. The 0001-exposure log is shown, but other test results are similar.
I find this deviation larger than expected. Is this normal, or do I have a GPU/opencl system which is not operating correctly?
If I produce darktable output, using my own pictures, with or without GPU, I see no visual difference. I have done other calculations using my GPU outside darktable and so far my GPU seem to operate correctly.
./run.sh 0001-exposure
Test 0001-exposure
Image mire1.cr2
CPU & GPU version differ by 77414 pixels
CPU vs. GPU report :
----------------------------------
Max dE : 25.74879
Avg dE : 0.02992
Std dE : 0.26501
----------------------------------
Pixels below avg + 0 std : 97.23 %
Pixels below avg + 1 std : 97.48 %
Pixels below avg + 3 std : 98.91 %
Pixels below avg + 6 std : 99.51 %
Pixels below avg + 9 std : 99.74 %
----------------------------------
Pixels above tolerance : 0.28 %
Expected CPU vs. current CPU report :
----------------------------------
Max dE : 0.00000
Avg dE : 0.00000
Std dE : 0.00000
----------------------------------
Pixels below avg + 0 std : 100.00 %
Pixels below avg + 1 std : 100.00 %
Pixels below avg + 3 std : 100.00 %
Pixels below avg + 6 std : 100.00 %
Pixels below avg + 9 std : 100.00 %
----------------------------------
Pixels above tolerance : 0.00 %
OK
Total test 1
Errors 0
see test-20230122-170755.log
I am on Debian 11.6 stable
darktable master dev code release-4.3.0-277-g5890e107f
Quadro RTX 4000 GPU.
NVIDIA proprietary display driver on Debian, NVIDIA 470.161.03-1 amd64
Intel Core i7-3770K CPU @ 3.50GHz Ă 8
The output of ./darktable-cltest and clinfo are attached.
Since this is the first time I run this test, I might very well have misunderstood something ⊠but as far as I understand, my darktable seems to be running OK:
Test 0001-exposure
Image mire1.cr2
CPU & GPU version differ by 77416 pixels
CPU vs. GPU report :
Expected CPU vs. current CPU report
OK
Total test 1
Errors 0
I am on Manjaro, Ryzen 3900X, 32 gig RAM, GTX-1660 Ti, Nvidia proprietary. dt version = 4.3.0+275~g2d51f435b
Just tell me if you want me to run some other tests.
You and I get the same CPU versus GPU result, Pixels below avg + <N> std , for different CPU and GPU. That assures me that my GPU/darktable/openCL works in the same way as your system.
Intuitively, I think Pixels above tolerance : 0.28 % is higher than expected, but I have not checked the code and perhaps all deviations are due to non significant differences in least significant bit, or similar. I do not know.
Just a note that the GPU vs CPU diff is âexpectedâ and there since the start of the regression testsuite. Most diffs are for pixels on the borders. This has been worked as much as we could at this point (Iâm not saying we couldnât do better).
Note also that I tun the testsuite every night on my server and publish the results (one commit) in the darktable-tests Git repository.