Does anyone know how efficient / cheaply they can use their servers? I'm guessing the chat part of the service save for file / image hosting is probably pretty cheap, but the low latency voice chats might be pretty costly, even if they can efficiently host them on virtual servers.
Discord's voice chats have no apparent upper limit in how many concurrent users they support - they basically say "the upper limit is how many your client device is able to support without crapping out".
I haven't read into this but it seems like they're doing peer-to-peer for audio or the server load is INCREDIBLY efficient, given this.
This is observable to still be the case as an end user. When the discord servers are having issues, people's voices become inaudible. This can be resolved by moving the server to a different, less loaded region, even if that region should have worse connectivity to the users in the voice chat. For example, my raid group often have to bounce our server from Europe to the US to workaround reliability issues on the EU servers.
edit: found it. they use a SFU forwarder. That's the cheap version of going full centralization (MCU) benefits. they probably have a better deal on bandwidth than CPU to justify that, or all their use cases work fine with only one person transmitting at once, which gives you the same benefit of a MCU with less cpu usage...
