CPU device 2 discarded

[obe (Olaf Berthelsen)]

Hi’ @Entropy512
Thank you for your response. I really appreciate your efforts in explaining all this to me and I hope other users also benefit.

When studying the topic it strikes me how impressive it is that developers put such a huge effort into developing and maintaining complicated free software like darktable.
It’s awesome, thank you guys out there!

Yes I’m on windows.

Now, I think I almost got it right, see below……

@Entropy512

The OCL drivers on the system list a set of given possible targets - in your case, it looked like NVIDIA GPU, Intel GPU, and Intel CPU. Darktable didn’t even consider the third option here because, in general, native code almost always works much better in that use case.

…and darktable displayed the message “discarding CPU device 2……” to tell me this. The CPU is device 2 because darktable has three possible targets and the internal numbering starts with 0. Correct?

@Entropy512

That honestly also means you likely don’t want to try using the Intel GPU target either - Beignet is blacklisted across the board for all OSes, and NEO is still blacklisted on Windows because it seems to be highly immature on Windows.

The Intel GPU is accepted as device 1 and using the standard setup, opencl_device_priority = star/!0,star/star/star (PIXLS.US doesn’t get my Danish keyboard “*” right) the Intel GPU is used the most. NVIDIA is used very little. That is the reason why I got into this issue following this thread:

Windows 10 running Darktable not using PC at full capacity

Hi, my laptop has a dedicated GC in addition to the integrated one. I have the following, with GC #1 beeing significantly faster than #0. 3.331822 [opencl_init] kernel loading time: 1.0691 3.333816 [opencl_init] OpenCL successfully initialized. 3.336808 [opencl_init] here are the internal numbers and names of OpenCL devices available to darktable: 3.342791 [opencl_init] 0 'Intel(R) UHD Graphics 620' 3.345784 [opencl_init] 1 'GeForce MX150' 3.347778 [opencl_init] F…

But everything is apparently working fine in darktable in the standard setup using the Intel GPU. How would I experience a malfunction?

You suggest that I exclude the Intel GPU altogether maybe by setting opencl_device_priority = !1,star/!1,star/!1,star/!1,star? This works also very well and now the NVIDIA GPU is almost used exclusively. Should I prefer this?