12-28-2014, 07:00 PM
I don't think it's as much about speed as it is about roundtrip times. Nowadays the home connections are LFP (long fat pipes), the technology is more oriented towards the speed than the delay.
Most of the network traffic comes from streaming chunks. All the other packets are only a few bytes long, but for a normal-shaped world, a single chunk is around 8 KiB. So a player connecting, with viewdistance of 10, would require 8 KiB * 21 chunks * 21 chunks = 3.5 MiB burst on game start. Of course the player will start much sooner than they get all the chunks - normally when they have just a few chunks around them, I'd say 5 * 5 chunks, which means 200 KiB of data.
When the player is moving, the chunks they require are at most double the edges, so for viewdistance of 10 that means some 41 chunks, 300 KiB. How often does a player cross the chunk boundary? With minecarts travelling at top speed, 8 blocks / sec, the player needs a new set of chunks every 2 seconds. So the worst case network usage for absolutely smooth gameplay is 300 KiB / 2 seconds, or 150 KiB / sec (1200 kbps) for each player. This is regardless of the server software used.
Note, however, that this is only the theoretical number, with regular gameplay where people mostly stay at once place, the network speed requirements will be much lower. When walking (top speed 4.3 blocks / sec) the top bandwidth is 80 KiB / sec (650 kbps), and that's only when walking in a straight line.
Most of the network traffic comes from streaming chunks. All the other packets are only a few bytes long, but for a normal-shaped world, a single chunk is around 8 KiB. So a player connecting, with viewdistance of 10, would require 8 KiB * 21 chunks * 21 chunks = 3.5 MiB burst on game start. Of course the player will start much sooner than they get all the chunks - normally when they have just a few chunks around them, I'd say 5 * 5 chunks, which means 200 KiB of data.
When the player is moving, the chunks they require are at most double the edges, so for viewdistance of 10 that means some 41 chunks, 300 KiB. How often does a player cross the chunk boundary? With minecarts travelling at top speed, 8 blocks / sec, the player needs a new set of chunks every 2 seconds. So the worst case network usage for absolutely smooth gameplay is 300 KiB / 2 seconds, or 150 KiB / sec (1200 kbps) for each player. This is regardless of the server software used.
Note, however, that this is only the theoretical number, with regular gameplay where people mostly stay at once place, the network speed requirements will be much lower. When walking (top speed 4.3 blocks / sec) the top bandwidth is 80 KiB / sec (650 kbps), and that's only when walking in a straight line.