how it is possible that computers are so fast that dozens of people from across the world can play video games together simultaneously?


I’ve been thinking about this lately. I guess it just doesn’t make sense to me that 40 years ago we were barely able to move pixels across a screen and now there are games where even hundreds of people can play games like first person shooters on servers simultaneously where reactions down to the millisecond commonly decide the outcome of a game. How can we match the inputs of everyone and have them appear on someone else’s screen? Is it simply that information travels at the speed of light and we are really good at organizing it?

In: 20

Two factors: one, a lot of that information is, literally, travelling at the speed of light through fiber optic internet cables. two, most games employ some prediction technology to compensate for the “lag” (lag is the time it takes for the signal to be encoded, travel time, decoded, and for the game server to think about what to do)

so often you are really shooting at the “prediction” of where the server thinks your enemy might be in the future (because it takes time as well for the server to send you information) and at the same time the predicted events are checked vs the actual input from the players and carefully updated.. this may cause a player to teleport, may cause hit registration errors, etc, but playing WITHOUT any lag compensation has it’s own suite of issues

the exact details of how lag is compensated varies from game to game

Sure thing, let’s boil it down to the basics:

Faster computers: We’ve come a long way since the days of Pong. Computers today are basically supercharged compared to the oldies, packing more punch in a fingernail-sized chip than an entire room of 70s computers. All thanks to this dude Moore who said we’d double our computer power every couple years. He was right.

Internet magic: The internet is kinda like an ultra-speed highway for your game actions. You press a button, and Zoom! off it goes at nearly two-thirds the speed of light to a game server. That server then tells all the other players, “Hey, this dude just shot you!” All of this happens faster than you can say “lag.”

Smart Guessing: Games also have a trick up their sleeve called interpolation. Basically, your game takes a guess at what’s happening between those superfast updates, like continuing to show a player running forward. It’s like when your friend tells a long story, and you zone out but can still nod along because you kinda know where it’s going.

Server Updates: Servers do a thing called ‘tick rate’ which is like a game’s heartbeat. The faster the tick rate, the more ‘alive’ and responsive the game feels. But just like our own hearts, sometimes they skip a beat or two, causing what we gamers dread most: lag.

So in short, we’ve got wicked fast computers, a lightning-speed internet, and some clever tricks that make games run smoothly. Next time you snipe someone from across the map, remember, there’s a whole lot of tech working to make that epic moment possible!

Anyone who autofragged themselves with a rail gun in Quake 2 in 1998 because their ping was over 250 and it would freeze for 5 seconds then teleport you ahead of the slug you just fired put your hands in the air and say AYYYY-OHHH!

To put processing speed into perspective, a modern CPU can, in one second, perform a number of operations that would potentially take a human decades to complete. This obviously depends on complexity and ultimately falls on the programmers to optimize that power, but it really shows the scale between our perceptions of time and what computing can be done in just a few milliseconds.

The Intel 8086 CPU was released in 1976, and it had 29,000 transistors.

The Intel Core i9-12900K processor, released in 2021, has about 3 billion transistors. And it’s already getting outdated..

And this is without even talking about video cards, which didn’t exactly even exist in the 1980s.

So yeah, microchips have become astonishingly more powerful. They’ve been by far the fastest-improving technology in human history. And the devices that control the Internet – switches, routers, hubs – also use microchips, so they gained a lot from this. The infrastructure of the Internet, fiber optic cables crisscrossing the globe, has also been continually improving over the decades.

Last but not least, most networked games don’t show you *exactly* what the other players are doing at a given instant. They predict it based on the player’s trajectory, and make corrections after the fact if necessary.