Linux

Damn straight. Another reason not to buy a pi.

If you think in flops per watt, maybe a little bit, but not a lot. Do you have one or two good procs for almost free, or half a dozen new sbcs at $100 each? Takes a while to save back that amount in power.

That just means they become 100% efficient in winter!

my 20 year old pc runs at ~5°C above room temp under load

So do Raspberry Pi?

but they're not cheap any more

People say this, but they really are still cheap.

The original Raspberry Pi Model B launched for £22 in 2012. The entry level Raspberry Pi 5 is £46, but adjusted for inflation that's only £32 in 2012 money. So only £10 more expensive in real terms.

Raspberry Pi Zero 2 W is only £14.40, which is only £10 in 2012 money. Compare this to the original Raspberry Pi Model A, which launched for £16.

People look at the headline cost of the high end RPi 5s (£115 for the 16GB model, £76 for the 8GB), but fail to recognise that there was nothing comparable to these in the Raspberry Pi lineup before, and these are not the only models in the Raspberry Pi lineup now.

Pi is popular with me because it's time efficient. Meaning: when I am trying to get it to do something, it takes less of my time to make the thing actually happen on Pi hardware as compared with most of the other small / embedded alternatives. Notable recent exception: ESPHome on ESP32 hardware, but even there the more limited variation of Raspberry hardware makes it similar to those fruity phones, MP3 players and computers - since there are a limited number of variations, you can usually find information specific to EXACTLY your setup, instead of having to infer from something almost the same, but figure out little wrinkles here and there due to differences between what you are working with and what you are reading about on the internet.

That's only true for the high-end Pi 5. Lower-powered models like the zero 2 are still cheap, and they're a lot easier to find than a few years ago.

Technically a Pi is a single chip computer but they're called an SBC because they replaced stuff like a Motorola 68HC11.

this is the way

This is generally not true. If you are using your laptop as a home server chances are it's going to be idling 99% of the time and laptops are generally pretty good in terms of idle power draw if you manage to disable the screen (or just disconnect it, take it off and find a way to repurpose it)

And in terms of environmental impact saving a laptop from landfill is definitely better since the majority of a computers impact is from the co2 emmissions from the manufacturing process. And this isn't taking into account the likely ethical considerations such as supporting terrible mining practices for resources like cobalt.

A good "rule of thumb" to remember: if your electricity rates average (somewhere near) $0.11/kWh you can take the average power draw of a device in watts and that is equal to what it will cost to run that device 24-7 for 365 days.

So, if that cheap PC draws 50W more than an alternate solution, it's costing you $50 more per year to use it.

Some tasks are beyond any RasPi, but it's well worth evaluating if something like an N100 fanless mini-PC can handle it instead of loading up some Core i7 rig that's going to cost more to run in the first year than the N100 costs to buy.