What Digital Ocean droplet size should be chosen for an entry-level HF world able to support, say, 20 avatars at the same time with good performance? I assume a droplet can be upgraded and resized, correct?
If all the avatars are moving and talking at once you need 4 vCPUs on a modern server. If say there standing you can get away with 2-3 vCPUs. So look for plans that have at least 2+ vCPUs you can use. I think there is an info graphic If you use High Fidelity’s cloud domains. https://docs.highfidelity.com/create-and-explore/start-working-in-your-sandbox/digital-ocean
You can also check out this post where I’ve put my hosting planes. It will give you an idea of what you need hardware wise to host what. Endless Worlds: Managed hosting for High Fidelity
What is the amount of bandwifth one user requires now with high fidelity ? Bandwidth at home is going up this days.
When no one is moving or talking its a fraction of the bandwidth requirements but the second people start becoming active things change fast. Lets say you have 20 avatars, its not unrealistic to see it use 3-5 mbps per avatar. The High Fidelity server I believe caps it at 5 mbps by default and generally that should work well.