I not think (now), its not provide real world improvement and not worth to invest (develop) it, but see below:
The weak points (as i think) of multiple GPU or more stronger GPU and CPU distribution:
- PC need to handle enough PCie slot (for multiple GPU)
- Enough PSU (like may 800W?) power for multiple GPU?
- CPU can be bottleneck
- Price, like 2x GPU price
- Even budget GPU provide decent performance, see here: Budget GPU for PL
- Even budget GPU can provide good AI masking performance, and decent Export performance
- Powerful GPU provide great performance, export can be a few second per photo.
- User base can be small. I guess not so much user want to export 1000’s of 100Mpix photos.
- Real world advantage can be small. If we talk about percentage, difference may looks nice, for example, to say lets 100%. But in time, its mean may not 5 second one photo, but 2.5 second. Make not to much difference (for most of us).
- In GPU and CPU distribution: CPU performance may 5-10 less, so may distribute between GPU and CPU may make less sense.
- Export (performance) queue may not well balanced.
- Export process already able multiple paralel export, what improve a bit of export performance (usually 3-4 is the ‘sweat point’)
- Performance improvement may not linear (may just 1.5x or less)
I think in theory looks ‘simple’, but in real life i not see too much software do that. I only know a very few of them, example from Video editing: Flame (Autodesk) may use 2 GPU, however its need at minimum 64GB of of GPU (for single GPU, but 96-128GB is optimal), and not all operations accelerated (afaik). Diamond Film restoration able to use multiple GPU, mainly for render afaik.
However, can be great if we can choose between the processing for Editing (and AI mask) and Export. Example: GPU for Editing and CPU for exporting. It’s may helps for GPU VRAM <6GB. Of course, in the example Export the CPU export far slower vs GPU export, but may export times less important for some. Or if someone use few/less AI mask, than the opposite: CPU for Editing, GPU for export.
But yeah, may GPU and NPU distribution for different processes can be in the future a niche, but real world improvement is questionable at least.