Oh, that's interesting. TrueNAS is available on Debian now, so I wonder if there would be a big drop in power consumption.

Lawrence Systems just ran benchmarks[0] between TrueNAS Core (FreeBSD) and TrueNAS Scale (Debian), but they didn't include power consumption, unfortunately.

[0] https://www.youtube.com/watch?v=BoiHHnBDg0E