Apologies if your question has already been answered. The mailing list has
been acting up for me lately.
To my knowledge, GIMP does not utilize multiple GPUs. When GIMP 2.8
launched, it had just enabled GPU acceleration via OpenCL and at the time,
I myself had two GPUs in my computer. I had taken a look at the resource
monitor while running various filters and I noticed that only one of them
was being used. This may have changed in recent versions but I have not
seen nor heard of multi GPU support having been added.
Although I'd love to be wrong about this :)
On Fri, Nov 16, 2018 at 1:29 PM notker88 via gimp-user-list <
[hidden email]> wrote: