Darktable: OpenCL and Intel/AMD - GPU necessary?


I’m looking for a new laptop and stumbled over the question, if I really need a dedicated graphics card. By far the most laptops in my desired price range are shipped with Intel UHD 620, some use AMD Vega 8/10, NVIDIA MX150/250, 1050 or something like that. My current laptop (XPS 15) has a 540M and is about 6 years old.

Since I don’t play any demanding games on my laptop the only thing that came in my mind, why a dedicated GPU would make sense, was darktable. So there are mainly two questions that arise:

Apparently Intel (and AMD?) GPUs are blacklisted for OpenCL in darktable, can someone confirm or disprove, that with an Intel GPU OpenCL does not work?
Apart from that, what are the advantages of using a dedicated GPU with darktable, how much is the speed gain? Is there anything else that might be relevant?

Thanks in advance!

It is my understanding that Intel’s openCL driver is so buggy that it had to be disabled.

The speedups with a dedicated GPU (a good GPU) are significant. However, my main editing rig is CPU only, and it doesn’t bother me.

Welcome, @pulga!

AMD APU (GPU and CPU on single die) devices such as my A12-9800 (desktop not laptop) are supported, but the speed-up is modest. The more recent AMD devices that are directly supported by ROCm https://rocm.github.io/ROCmInstall.html would certainly be worth considering if they are within your budget.

Speed gain? I get about 2x and change. Dedicated GPU can get 4x and change. See also these threads:
Using AMD APU as second OpenCL device?
darktable speed (in general, and when using two monitors)

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Many thanks to all!
Luckily I found a Thinkpad T590 with an MX250 for ~1100€ (campus) which would solve this issue, so I think I’m going to get that one.

I have a laptop with an Nvidia mx150 and the speed is considerable. The pain is switching between cards.

I use ROCm Open Source drivers which work just fine! Intels beignet implementation for OpenCL is totally buggy. I’ve tried it a few month ago and all you get are segfaults.

AMD works fine for me with Vega10 and ROCm. I also have 1900x in this system.