My laptop from 2011 idles at 8W, with two SATA SSDs. I have an Intel 10th-gen mini PC that idles at 5W with one SSD. 3W is not groundbreaking, but for a computer you paid $0, it would take many years to offset the $180 paid on a mini PC.
That is the key. The RPi works for idling, but anything else gets throttled pretty bad. I used to self host on the RPi, but it was just not enough[1]. Laptops/mini-PCs will have a much better burstable-to-idle power ratio (6/3W vs 35/8W).
> That is the key. The RPi works for idling, but anything else gets throttled pretty bad.
I don't have a dog in this race, but I recall that RPi's throttling issues when subjected to high loads were actually thermal throttling. Meaning, you picked up a naked board and started blasting benchmarks until it overheated.
You cannot make sweeping statements about RPi's throttling while leaving out the root cause.
amd64 processors will have lots of hardware acceleration built in. I couldn’t get past 20MB/s over SSH on the Pi4, vs 80MB/s on my i3. So while they can show similar geekbench results, the experience of using the Pi is a bit more frustrating than on paper.
RPi is amazing for IOT tasks cuz it’s pretty portable but not for running general purpose server tasks, you’d get better performance per watt with used gear
Free yes. Power efficient no. Unless you switch your laptops every two years, it's unlikely to be more efficient.