Look in task manager, it will list your GPU's as Windows see them under performance tab, GPU0 GPU1. Win 11 right click on window icon on bottom of screen, choose task manager

Not enough information. But in my experience BI does not need a GPU, but the correct setup from the camera to BI is important. The CPU is important and I would go for and have i7-14700 for 65w and 28 cores and Igpu. Keep your old GPU and if need be put half of the cameras on it and half on the Igpu....

I run Unraid with all my dockers, NAS, and VM's in one lower power box now then my now Dead Thread Ripper 2950 Unraid. At least half the power savings if not more at 165 Watts. 100 TB 3 NVME Media BI and of course Docker and VM playing. I use a Synology as a Mirror backup.

I read your issues and had to replicate as I haven't exported any video file in many versions. And was a bit worried. I came to the conclusion you are using a potatoe and/or have ignored all best practices, Like NTP. Those 30 years of IT do not help today. How do I know; the same. My 30 years of IT ...