I have a Raspberry Pi 4 Model B with 8GB of RAM, and I'm looking for a bit more powerful solution that would have similar power consumption. I would like to host a Minecraft server, but chunks take too long to generate. Do you have any recommendations?
To give a different opinion than all the thin-clients, old laptops can be a good choice too. I am a bit preferrential to really nice old thinkpads.
If you buy them used you can get insane prices (~$40) and also you get all the laptop conveniences of a keyboard, screen, battery (for power failure). Also I think the power/performance ratio is pretty much the same to the thin clients.
Using the laptops battery isn't a good long term solution though as having it plugged in all the time will wear it down fast, not to mention that the battery is build for maximum energy density and not durability/safety. It just simply not working when it is finally needed is almost a pretty light issue when it can just also inflate and pose a huge fire risk next to all of your data. Laptops are great power efficient platforms though for servers
First off, I think you're completely right in that laptop batteries are definitely a non-ideal solution. And, I'm really not an expert in this, so take my words with a grain of salt.
You could mitigate a bit of the dangers by doing some of the following (I only did the first):
Reducing the max charge level to 50% of the capacity.
Monitor your batteries health to alert for any discrepancies.
Switch out your batteries every couple of years (which is super easy without downtime on the aformentioned old thinkpads).
If you are an under $100 budget, there seems to be an argument that maybe you are willing to risk a little bit for that extra power reliability.
For that the laptop has to support a charge level on a hardware level though, just setting a limit will cause it to constantly switch between using the battery and charging the battery which would be much worse than keeping it at 100%. Most older and budget systems don't support that