Hello, I had a lot other tasks, so it took quite a while. Thanks again for looking into it.
Having measured it, and cleaned up as much as possible, it seems not as bad as it was.
Thnx again. BR.
Timings, fYi, on the same task (10000xNST, 512x512 image)
Tesla K80 Colab: 3524 s (will be dependent on shared usage …)
GTX1650TI 4 GB Notebook: 2230 s
GTX1080TI 11 GB as eGPU over Thunderbolt 3: 580 s