Our instance runs on @netcup's VPS 3000 ARM G11, i.e. a 12 core KVM VM on Neoverse-N1 #ARM64 server hardware.
We don't have a lot of users yet. However, when users with >1K followers moved to our server, the #sidekiq queue did grow (running the default install of Mastodon, no Docker).
So we used the opportunity to do the configuration tuning that had worked well when some of us scaled an AMD64-based Mastodon instance previously: create several sidekiq processes by copying and adapting a systemd service file – roughly as detailed by @leah here: https://leah.is/posts/scaling-the-mastodon/
This sped up sidekiq enormously – as it had done earlier on different hardware.
To sum up, we highly recommend ARM hardware for running Mastodon instances because it eats less energy and performs well enough.
Thanks!
Am diving in. 
