Let’s talk about jitter – Why wireless connections are always worse than wired for gaming

Pop quiz! What’s the most important thing to have if you want to guarantee smooth online gaming? If you said a fast internet connection, then you are wrong!

While having fast internet helps, it’s only a small piece of the puzzle and it won’t at all guarantee that your online gaming will be smooth and lagless. To really guarantee an enjoyable online gaming experience, we need to talk about jitter.

What is internet speed?

When we talk about internet speed, what are we actually talking about? We are talking about how fast information can be sent from one computer to another. Your download speed is how fast your computer can receive information from another computer, and your upload speed is how fast your computer can send information to another computer.

And if that were the end of it, it would seem as if speed was everything. If you can download and upload at 30 megabits per second then that’s just how fast and smooth your internet runs.

Except that’s not really what’s happening. Information is sent from computer to computer in the form of packets. We’re vastly simplifying here, but for the most part any data you want to receive comes in several pieces. When your computer receives all those pieces it puts them together to form… well whatever you were trying to do. This could be an e-mail, an image, that movie you are streaming over Netflix, or that punch your opponent just threw in an online match of Street Fighter V.

The key thing to understand is that each individual packet of data can get to your computer at a different speed.

Now let’s look at two different internet connections.

Computer A is downloading data. In the first second, it downloads 10 megabits of data. In the second, it downloads 10 megabits of data. In the third, it downloads 10 megabits of data. It downloaded 30 megabits of data in three seconds. It’s pretty clear that this computer has a download speed of 10 megabits per second.

Computer B is downloading data as well. In the first second it downloads 5 megabits of data. In the second, it downloads 24 megabits of data. In the third, it downloads a single megabit of data. It too will have downloaded 30 megabits of data in three seconds, giving it a download speed of 10 megabits per second.

If these two computers were downloading a file, on average they would finish at the exact same time. The same holds true for streaming online video, listening to music, browsing the web, basically doing anything you normally do online.

But these computers aren’t equal. Computer B experiences weird audio drop outs in their Zoom meetings every so often, and for some reason it constantly gets spotty performance when gaming online.

Why?

Because of jitter.

What is jitter?

We have concluded that your internet speed is essentially the average speed that you can send and receive data, or more specifically, the average speed at which all your data packets are sent and received.

Jitter, on the other hand, calculates the difference between each packets actual speed, and your connection’s average speed. Again, we’re vastly simplifying here, but let’s use our example from before to get a better picture.

Computer A has a speed of 10 megabits per second. Over three seconds, one would expect 10 megabits to be transferred each second. Computer A does, in fact, do that, giving it essentially 0 jitter (Yes, this is basically impossible in real life. Just treat this as a thought experiment).

Computer B has a speed of 10 megabits per second as well. In first second, it transfers 5 megabits of data, which is 5 megabits off the average expected speed of 10. In the second, it transfers 24 megabits of data, 14 off the average expected speed. In second three it transfers just one megabit of data, 9 off the average. On average that’s 9.3 megabits of jitter.

“WHAT IS THIS IDIOT DOING!” is what you’re probably thinking “THAT’S NOT HOW YOU CALCULATE JITTER!”

You are right. I’ve been using these numbers as a thought experiment. We normally talk about internet speed in data per second, so I talked about jitter in data per second. But in actuality jitter is calculated by measuring the individual speed of each data packet, not by measuring the amount of data sent per second. It is, in a sense, the opposite of what we did in our thought experiment. However, the principle is the same. Certain packets will get there faster or slower than others. A computer that transmits and receives packets at a consistent speed has low jitter and one that transmits and receives more erratically has a high jitter.

Why does jitter matter?

I’m going to say something controversial to many PC gamers out there. For most applications, jitter doesn’t matter.

As I said before, when downloading a file, the high jitter and low jitter networks will operate at about the same speed. When streaming online video, you’d think jitter would cause a problem but all online video players employ a massive buffer that really takes jitter out of the equation. Let’s face it, that’s 99 percent of what you do on the internet. Viewing webpages and e-mail is just another example of downloading a file. Watching a livestream from Twitch is basically the same as watching a video on YouTube.

But let’s look at the two examples in which jitter does start to matter, video and voice chat and online game playing. Do you see a difference in these applications as opposed to the applications we mentioned above.

The most important difference is that voice chat and gaming deal with data in real time, while the other applications don’t. It doesn’t quite matter if you see your YouTube video immediately or if it buffers for a few seconds and then you see it, you’ll still get to see full and smooth with no interruptions. It doesn’t quite matter if your download speeds up and slows down a lot or downloads at a constant speed. As long as the file gets there, you are good.

But when holding a video conference, it does matter if certain packets of data go faster or slower than others. If the audio data in the middle of a conversation suddenly slows down, you’ll get strange audio artifacts or audio cut-outs.

The same thing goes for gaming. If you press a button and the data packet that has that button press suddenly slows down, it won’t matter that your speed is fast on average. That single button press will end up lagging, causing stutters, and generally ruining the online experience.

Most web applications deal with large amounts of data in which the only thing that matters is the whole. If you are downloading a 5GB file, it doesn’t matter how all the individual parts of the file get to you, it just matters that the file eventually gets to you at a decent speed.

But voice chat and gaming deal with many very small amounts of data, and each individual one matters. Experience slowdown in individual packets here, and your performance suffers.

What does this have to do with Wi-Fi?

There’s been a bit of a debate in the gaming world. Do you need a wired connection or can you game over Wi-Fi? People point toward blazing fast wireless internet speeds as evidence that you don’t need a wired connection for good gaming.

And, they are right. You don’t “need” a wired connection for good smooth gaming, but boy howdy it helps.

I’ll let Mike Z of Lab Zero Games explain it in this poorly edited internet video.

For those of you who are allergic to YouTube videos, here’s the deal. Wireless speeds can get very fast, but there’s something they have to deal with: interference. Your data is being broadcast through the actual, factual, air, and stuff happens in the air. This stuff can interfere with Wi-Fi signals.

And what is this stuff? Take your pick! It could be a competing Wi-Fi signal causing a tiny blip. It could be someone walked past the wireless router with a big sheet of metal. It could be… I don’t know… solar flares. The point is, something will, and more importantly, something is always interfering with Wi-Fi signals. It’s just that we don’t usually notice because this interference only effects a few data packets which are then delayed and reset. Not a big deal for most applications on the web, but a major deal for gaming.

Yes, Wi-Fi creates connections that might have high speed, but also have high jitter, and this effects performance in a gaming environment.

A wired connection could have a lower speed yet still experience better gameplay because it is more consistent. In fact, many games these days have netcode that takes low speed internet connections into account. You can have a decent gameplay experience with only average speeds.

You can’t have a decent gameplay experience with high jitter. You can do a lot to minimize your jitter but Wi-Fi will always, ALWAYS introduce jitter. It’s also worth noting that there are sources of jitter other than wireless connections. Network congestion can cause jitter. Faulty devices can cause jitter. But the point here is that you want to keep your jitter as low as possible and one way to do that is to use a wired connection, rather than a wireless one.

How can I check my jitter?

There are lots of jitter tests online but they usually check over very short periods of time, which doesn’t really give you an accurate picture of your jitter. The best way to do it is the same way Mike Z did, by running a ping test.

Open up a command prompt and types this:

ping 8.8.8.8 –n 30

This will ping Google’s public Doman Name Server for 30 seconds. You can, of course replace the 30 with whatever interval you want, but I personally feel 30 is a good enough time to get a picture of what your connection is doing.

Here are our results:

We’re on a decently fast wired connection. Now I’ll do the same thing, except I’ll remove my wire and use a wireless connection on the same network with the router a room away from me. Remember, this is the SAME connection, the SAME modem, but I’m changing from wired to wireless.

As you can see, it’s still decently fast, but on Wi-Fi it becomes far less consistent. I could probably still get good performance from this connection, but I’d get better performance from my wired connection.

In short, wired is always better than Wi-Fi for gaming, period. Not to mention it’s a lot cheaper to buy a long flat Ethernet cable and some mounting brackets than to invest in a really powerful Wi-Fi modem which will run you hundreds of dollars.