My Celeron boxes spend most of their life at ~6W, burst to 15W. Drives are all attached via USB, but since these are Intel Broadwell based Celerons (5 years old now! wow, long in the tooth. time flies), there are 4x USB3.0 root complexes that can run pretty much full tilt.
Trying to go lower power doesn't feel worth it, particularly when the hard drives drink so much power.
I feel like I'm spilling the beans sharing this, but ServeTheHome has has an excellent "TinyMiniMicro" series on ~1L size mini-PCs, which are used in businesses a lot. They are much beefier boxes than my little celeron, now often 6 core with way higher clocks. They come with 35W and 65W cpus, but even the couple generations old models still tend to idle at ~10W & otherwise sip power only as demanded[1].
If power is your concern, get rid of your small hard drives. Switch to ARM? Meh.
Trying to go lower power doesn't feel worth it, particularly when the hard drives drink so much power.
I feel like I'm spilling the beans sharing this, but ServeTheHome has has an excellent "TinyMiniMicro" series on ~1L size mini-PCs, which are used in businesses a lot. They are much beefier boxes than my little celeron, now often 6 core with way higher clocks. They come with 35W and 65W cpus, but even the couple generations old models still tend to idle at ~10W & otherwise sip power only as demanded[1].
If power is your concern, get rid of your small hard drives. Switch to ARM? Meh.
[1] https://www.servethehome.com/hp-elitedesk-800-g4-mini-tinymi...