These things are great for !boinc@sopuli.xyz often time leagues more efficient per watt in terms of computation than regular PCs. I have a couple of 'em working on cancer research and computing to develop an open-source patent-free covid antiviral. You don’t need a PhD to make a difference, all you need is a processor :)
I did a quick Google.
https://web.eece.maine.edu/~vweaver/group/green_machines.html
Is the best actual test data I can find. It uses a physical power meter, so it’s full system (not TDP or self reporting power consumption).
And it’s a few years out of date.
Seems like Apple silicon is the winner (and will probably continue to be).
The Xeon that beats the rpi4 for GFLOPS/watt is an e5v3, which was launched in 2013 and EOL in 2021.
So there will absolutely be some new Xeon CPUs that will perform better.
However, for a $50 device, it’s probably the best GFLOPS/watt/$ from what little empirical data I can find
