Not go as HAM on commercial server hardware. iLO is really nice for management though…

I’m using ZoneMinder on my end with more rudimentary motion detection, hence CPU detection. (My current hardware is pre-IOMMU on the mobo, so no pci passthrough for me…)

That said, if you have hardware that can handle X (via CPU, GPU, TPU, etc), then you gotta decide how you want to spend that. Whether resources are spent more in analysis fps or evaluating higher detail frames is up to what you need.

Would you say that 15FPS is a good framerate for surveilance? Or could one get away with even less to lessen the resource requirements?

If doing CPU-based motion analysis, you could use a lower quality stream (if available from the cameras to avoid transcoding load) for motion detection, then use that to trigger recording on a higher quality stream.