Live data from Hacker News

The best thing that's ever happened for multiplayer games?

mas-bandwidth.com

31–40 of 100 posts

Re: The best thing that's ever happened for multiplayer games?

#31
post #15

Earlier quoted context omitted.

Is there any reason that transmitted data would be much larger than player inputs (e.g. keystrokes and mouse movement)?

Typically you send state, not inputs. To prevent cheating.

Huh? If the server trusts the client to send state then the client could potentially send invalid or unfair state. If the client merely sends inputs then it can't just decide to manipulate the state that way.

Re: The best thing that's ever happened for multiplayer games?

#32
post #18

"This is because my space game sends a lot of bandwidth. 10-20 megabits per-second per-client" What is this game doing that uses so much bandwidth? Pretty sure most games use something like 2mbps.

It's a ludicrous amount of bandwidth even for a 1,000 player game, and a strong indicator that this developer is doing something very wrong.

It's like someone saying their project repo has 10-20GB of source.

(btw game server network data is usually trivially and insanely compressible, far more than text)

Re: The best thing that's ever happened for multiplayer games?

#33
post #15

Earlier quoted context omitted.

Is there any reason that transmitted data would be much larger than player inputs (e.g. keystrokes and mouse movement)?

Some games are networked deterministically, so that you can send only the inputs, and the game plays out exactly the same way (down to a checksum matching for all game state in memory across all players). For example many RTSs are networked this way. They can have thousands or tens of thousands of units, but send only inputs. The classic article on this being 1500 archers on a 28k modem: https://zoo.cs.yale.edu/class…

Haha of course it's Age of Empires. The lag was insane because out of 8 players, there'd always be that one guy. AoE2 also had bugs with determinism, causing games to sometimes end because one person went out of sync. Even the HD remake had those issues. The even later DE remake seems to have fixed it, but it still depends on this really finicky math library that doesn't work exactly right in Wine/Proton.

Re: The best thing that's ever happened for multiplayer games?

#34

Earlier quoted context omitted.

Higher player counts and more detailed worlds? It's 2026 and we regularly watch 4k video streams @ 25mbps. Seems like games should be able to get away with sending this amount of bandwidth too for a higher fidelity experience.

Game data and video data have very different constraints. Depends on the nature of the game, of course, but with jitter and all that, video can just run a buffer and manage network conditions (more) trivially, but a game needs things to be a lot tighter to avoid gameplay-impacting desync

It's true plus you cannot just send a snapshot of 100 kilobytes or so from server to client with 1500 byte MTU with regular IPv4 packet fragmentation and reassembly due to packet loss amplification effects.

Re: The best thing that's ever happened for multiplayer games?

#35
post #15

Earlier quoted context omitted.

Is there any reason that transmitted data would be much larger than player inputs (e.g. keystrokes and mouse movement)?

Typically you send state, not inputs. To prevent cheating.

It's sending inputs that makes preventing cheating easier.

Re: The best thing that's ever happened for multiplayer games?

#36

Earlier quoted context omitted.

Client performance characteristics? Speaking very broadly... I can't imagine a game that'd need that much data unless it involved a lot of streaming assets (audio, video, etc) or really, really naive netcode.

> I can't imagine a game that'd need that much data I can :)

Maybe instead of leaving drive by comments like this you can explain this to the overwhelming majority of people in this thread who think it's bananas.

Re: The best thing that's ever happened for multiplayer games?

#37

Give me self host code any day. This feels like the bait and switch AWS likes to pull. Would rather rely on the server in my dresser drawer than AWS for as much as I possibly can.

this is painting a caricaturist view of AWS. they have been more or less stable with their prices and features. Their prices have mostly gone down ime. I have so far seen zero bait and switches and mostly things working as usual.

Re: The best thing that's ever happened for multiplayer games?

#38
post #23

Earlier quoted context omitted.

If a normal game sends 2mbps, then 20mbps would be 10 times as many objects.

Even 2mbps would be on the extremely high side. I doubt many mainstream games, if any, use this kind of bandwidth. Excluding games that stream video of course. A 6v6 game of Forged Alliance (12 players each moving hundreds of units around, many with simulated projectile weapons) uses 0.3mbps.

I was going to say this too.

Games don't need to send much data to sync game state across clients

Re: The best thing that's ever happened for multiplayer games?

#39
post #15

Earlier quoted context omitted.

Is there any reason that transmitted data would be much larger than player inputs (e.g. keystrokes and mouse movement)?

Some games are networked deterministically, so that you can send only the inputs, and the game plays out exactly the same way (down to a checksum matching for all game state in memory across all players). For example many RTSs are networked this way. They can have thousands or tens of thousands of units, but send only inputs. The classic article on this being 1500 archers on a 28k modem: https://zoo.cs.yale.edu/class…

Oh hey! I sometimes play a game called Cosmoteer that has deterministic lockstep multiplayer. That means in multiplayer every game has to synchronize on the exact same tick, receive all inputs from all other players and apply them on their exact same ticks, etc. The entire session is bottlenecked by the slowest player's machine. But it's very cool.

If any player desynchronizes, their state has to be erased and then completely re-sent from scratch so that they can start processing inputs correctly again.

Re: The best thing that's ever happened for multiplayer games?

#40

Earlier quoted context omitted.

You don't really ever stream games in normal situations in the same manner though. The content is mostly rendered client side, why does the server need so much bandwidth?

If a normal game sends 2mbps, then 20mbps would be 10 times as many objects.

At the absolute worst, a room full of 32-players in Quake 3: Arena would be sending 120 kilobits per second to each player. Fortnite peaks at ~400 kbps during the initial 100-player drop and goes down from there.

I understand that those are big budget games, but there is a lot of room for improvement in 10000 kbps.

Post reply on HN