Two AMD GPUs, displays connected to one, activity on both. What is happening?

[odonata]

I upgraded to a B650 MB (Arch using kernel 6.4.3) with a Ryzen 7700 with a builtin 2 cu GPU, my primary GPU is a rx6600xt (32 cus) with displays plugged into the DP and HDMI ports. When playing video or games, using nvtop ( https://github.com/Syllo/nvtop ), I see load on both GPUs. Why? What is running on the builtin GPU? Is there any way for me to see what tasks its being used for? From what I gather both GPUs are 10_3 variants, What happens if two AMD gpus with the same chipsets (navi 23 etc) are plugged in the MB? Lots of questions here, does anyone know what is happening?

[agd5f]

I upgraded to a B650 MB (Arch using kernel 6.4.3) with a Ryzen 7700 with a builtin 2 cu GPU, my primary GPU is a rx6600xt (32 cus) with displays plugged into the DP and HDMI ports. When playing video or games, using nvtop ( https://github.com/Syllo/nvtop ), I see load on both GPUs. Why? What is running on the builtin GPU? Is there any way for me to see what tasks its being used for? From what I gather both GPUs are 10_3 variants, What happens if two AMD gpus with the same chipsets (navi 23 etc) are plugged in the MB? Lots of questions here, does anyone know what is happening?

If you want to use the dGPU as the primary, make sure it is set as the primary in the SBIOS. Otherwise the platform may default to the built in GPU and when the OS loads it will inherit that from the SBIOS. In the case of multiple GPUs, the primary will be the one used by default on the system and then rendered content will be shared with the other GPUs for display if they have displays attached. Same thing for multiple dGPUs.