Google Stadia Preview – Get started with Google’s future vision for gaming

Google wants to offer all that with its game streaming service Stadia, which should come to the US and Europe later this year. Stadia was unveiled earlier this year and at Google I/O we got the first chance to play a game via Stadia and talk to some people about the technology behind it.

latency

The technology behind game streaming is easy to explain, but extremely difficult to implement properly. In the case of Stadia, there is special equipment in Google data centers on which the games run, based on AMD GPUs and x86 CPUs. On the other side of the line is a player who transmits commands via a controller. For example, if you press A, it will be sent to the data center. There it calculates what the game does next, a new frame is rendered and that frame is sent to the user.

The first thought that then occurs to almost everyone is that this introduces extra input lag and games therefore play less pleasantly. That is completely correct, Google also admits. At the same time, the company tries to put that into perspective.

During a technical session at Google I/O, for example, Google showed research into the latency in humans themselves. For example, according to the research, we need 20 to 40 ms to process visual stimuli and a signal from our brain to our hands to press a button on a controller takes at least 70 milliseconds. In addition, an HDMI signal, for example, takes 16 to 33ms to reach a screen. The point Google wants to make is that simply looking at a TV’s input lag and adding up the possible extra latency of streaming doesn’t paint a realistic picture; the total round tripis longer. Or as one of the Stadia engineers put it, “It takes less time for a package from a data center to reach you than it does for a command from your brain to reach your fingers.”

In addition, the influence of latency differs greatly per game or even per component within a game. Research that Google has done with users shows that the tolerance for lag is many times higher when users play an rts, compared to an fps or racing game.

It is still important to keep that extra latency as low as possible. That is why Google says it has been busy in recent years to build a streaming backend that can adjust the image quality at the millisecond level, depending on the available bandwidth. The vp9 codec is basically used for this, but in a completely different way than with offline coding, for example. After all, it is then possible to perform an analysis before you actually start coding: the well-known two-pass encoding. The YouTube implementation, where buffering is not desirable but acceptable, is also not sufficient for game streaming. Stadia will therefore always prioritize smoothness and latency over image quality.

In practice

I experienced this myself during the demos at I/O. There were several Stadia setups based on Chromebooks that were connected to different parts of the network. They all ran Assassin’s Creed Odyssey at 1080p at 30fps. When Stadia comes out later this year, resolutions up to 4k at 60fps will be supported, but unfortunately we weren’t able to test that yet. This was not about local demo setups; a Google employee assured us that the Stadia backend was running in a Google data center, as it should eventually happen all over the world.

On the first demo setup I tried, I wasn’t overly impressed with the image quality. This was partly due to the fact that I was very close to a large TV – much closer than you would normally sit – but probably also because the network in that room was just a bit more busy. Especially in the menus around texts, compression artifacts were clearly visible and the codec also had trouble with vistas with a lot of detail.

The second demo setup I tried allowed me to sit on a couch in a room that was used by far fewer people. The increased viewing distance, but as said also probably better internet, made the game look a lot better here. Still not as sharp as on a high-end PC, but as far as I’m concerned nice enough to enjoy the lighting effects, world structure, cutscenes and gameplay.

But what about that much-discussed latency? That was not too bad, helped by the fact that Assassin’s Creed is a game that can also be played with some extra input lag. Coincidentally, it’s also a game I’ve spent many dozens of hours playing on PC, so I have a good idea of ​​what the game would feel like in an ideal situation. Although I noticed that the game played a little differently, I did not feel limited in my actions at all. I didn’t feel that I could perform platform elements less well or that I was worse off in combat, for example. Very quickly the brain seems to compensate, so that as a player you have full attention for the game itself.

However, this is an extremely subjective matter. In recent months there have been many discussions in the editorial office about game streaming. Not only about the influence it might have on the game market, but also to what extent the extra latency and the loss in sharpness affect the gaming pleasure. It shows that avid gamers are more skeptical than sporadic gamers. That is easy to understand; they raise the bar. In addition, some people will be more sensitive to extra input lag than others. As with virtual reality and nausea, for example, the way people experience game streaming will differ from person to person.

The Stadia controller

The promise of game streaming is not only that you may save money because you do not have to buy hardware yourself, it should also make it possible, for example, to start a game on your TV and continue playing on your laptop, or even on your smartphone . In addition, it should be easier to stream a live session online or play multiplayer games with huge numbers of people. Unfortunately, Google is still keeping all that under wraps, so we can’t say anything about that yet.

What can be said about it is the Stadia controller that forms the basis of the service. Ultimately, it is intended to be directly connected to the data center, to transfer the signals as quickly as possible. This was not yet the case for these demos, probably because the Wi-Fi is so busy during a conference as I/O.