Dramatic time difference with similar computers

I’m running GigaPixelAI on MacPro 5,1:
I have two MacPro 5,1 configured almost the same.
Computer 1 is running Monterey, has a Radeon RX580 8GB vram and 128 GB RAM.

Computer 2 is running Big Sur has a Radeon RX 580 8GB vram and 64GB RAM.

Both running GigaPixel 6.3.3. with the all the sample files downloaded. Preference set to use GPU. with high memory allocation. When I run the same file, 11.8MB with the same GP AI configuration and model (Art&CG):
Computer 1 takes 8minutes and 28 secs.
Computer 2 finished in 27 seconds.

I’m noticing if I set the faster computer to use the CPU it gets the slow speeds similar to computer 1. Which makes me wonder if somehow the preference to use the GPU in computer 1 is not being honored and it is stuck somehow on the CPU.
Any an all suggestions are welcome.


Hi Clark

I can only speak for my experience with Video AI but I have also found it can ignore the CPU / GPU selection depending on the memory allocation. I highly recommend reducing the memory allocation to very low (e.g. start with minimum) and see if that “forces” the GPU to be used. Remember you can use Mac OS Activity Monitor to see the CPU core usage and GPU usage.