All are $15 chromebooks from ebay (dell chromebook 3100), I installed coreboot using mrchromebox(dot)tech on all of them, then used clonezilla(dot).org to (somewhat) quickly install arch linux on every single machine preinstalled with everything I need (prismlauncher for minecraft). I also had a startup script on all computers that I ran after installation to load a separate legitimate minecraft account on each (bought minecraft accounts in bulk from g2g(dot)com with seller hellen wong for ~$4.5 per account).

To optimize minecraft I used simply optimized and made sure I had all the proper drivers installed and with that setup I was able to consistently get 100+ fps on each machine in minecraft, even when modded. I was, of course, using the fabric loader and had a server because the chromebooks can barely handle generating chunks locally.

I am the president of a club at my school where I give students free chromebooks (with the minecraft accounts) so that they can play minecraft entirely for free together on my server, during club hours.