 Corsair Raptor K40 keyboard and M45 mouse are designed to provide best-in-class features and performance for gaming. Click now to learn more. Valve in-home streaming uses the power and compatibility of a Windows-based gaming PC somewhere in the house to enable a great gaming experience on other devices and operating systems. Basically anything that can run the Steam client, Windows, OS X, or Linux, can use it as long as the hardware is powerful enough. It works on inexpensive desktop PCs, notebook PCs, or even tablets. So what does it do? First of all, it's in beta, so all of this is subject to change, but the basics should be pretty much set at this point. So here you go. In-home streaming uses your gaming machine with a powerful graphics card, for example, your office or your man cave rig, to act as the server and to run a demanding game, then with as little latency as possible, convert that to an H.264 compressed video stream. It then sends that video stream over your home network to another machine, for example, your home theater PC that's hooked up to your TV, which acts as a client that can, without working very hard, decode that video stream and display it on the screen. At the same time, the client PC takes input commands from your game controller or keyboard and mouse, and, again, latency is key here, sends them back to the server to actually control the game. The idea is that any PC with adequate network performance and CPU horsepower can let you play your games, the games on your gaming rig, remotely. So what does it not do? It does not allow streaming over the Internet, although I suspect workarounds for that won't be much of a stretch for the technically inclined. It does not allow multiple people to use the server or streaming machine at the same time, so your office gaming PC can't have someone sitting at it working on spreadsheets while you're using the horsepower of that GPU to game downstairs. It will actually be running the game on screen at the same time, just like Nvidia's GameStream technology. Number three, it does not allow logging in from multiple locations on the same network to the same account and playing different games at the same time. We'll need Steam family sharing for that, which is hopefully coming soon. Number four, it does not allow higher resolutions than the connected monitor of the server PC. The game must run on both PCs at the same time, so if your desktop computer has a 720p monitor and your TV downstairs is 1080p, then your stream will be limited to 720p. The good news is that the opposite is not true, so as long as your gaming PC has the same or higher resolution as the other PC, your remote PC can scale that image down appropriately. Number five is it's a little bit finicky right now, and it does not have perfect game compatibility. In the future, I'd expect this to be much improved, and you should be able to stream most of the games in your Steam library, even the ones that you've added manually. Number six, it does not deliver the greatest image quality. It's seemingly capped at about 30 megabit per second, maximum streaming bitrate, so that means color depth will be lower, which is perceived as blockiness and what would otherwise be smooth color transitions, and it also introduces artifacts, some that are difficult to notice and some that are very, very easy to notice, such as these around a crosshair in Battlefield Bad Company 2. Moving on to hardware requirements, Valve has been pretty tight-lipped about these, probably because this functionality just went into beta and they are still working on it, but there are a few things that we know. CPU performance will have to be enough to decode and playback an H.264 video stream at whatever frame rate and resolution you're running. Officially, Valve supports 720p and 1080p at either 30 or 60 fps. Network performance also matters, but how many megabits or gigabits per second it can achieve is not actually the most important thing. Connection latency and reliability are much more critical than throughput. A theoretically faster N or even AC wireless connection will inherently drop more frames than a normal Ethernet or even a slow powerline network connection, because hardline networking performance is much less susceptible to interference. Speaking of interference, forget about 2.4 GHz N wireless. Even if the throughput is fast enough, there's so much interference on that frequency that 720p 30 fps isn't a great experience. 5 GHz wireless N was much better in my testing, but that's a subject for another video. Stay tuned for a follow-up where we take a closer look at network requirements. The other requirement is the PC actually doing the gaming has to be powerful enough to run those games. That's kind of a given. So, to hold this aside, we don't really know exactly what we need. If you are trying in-home streaming and you're wondering how your configuration is doing, pressing F6 on the client PC provides a somewhat useful little analysis bar that pops up and tells you latency, drop frames and stuff like that. I didn't always find that the numbers correlated directly to the gaming experience I was having though, so your mileage may vary, but at least it's in there. So, let's move on to the practical demonstrations. Obviously, if you have two powerful gaming rigs, you could stream between them, but gaming locally would usually make more sense in this case. So, I'm going to focus on some demos for you guys that show how I think this technology will be used. Here's demo number one. I'm using a Linux, in this case SteamOS machine, to run a game that doesn't natively run on Linux. Boom! Your entire Windows game library now runs on a modestly powerful Linux box. No excuse not to try it now, hey? In this case, this is Batman Arkham Origins running at 1080p, 60fps. And here's demo number two. This old, low-cost, low-power Sapphire machine has an AMD E450 dual-core APU with integrated graphics. In spite of its age and lackluster performance, I can have a console-grade gaming experience, that is to say 720p, 30fps, with no frame loss while playing the latest games. In this case, I've got Battlefield Bad Company 2 running here, but that was just for the sake of, you know, mixing up our games a little bit. Here's demo number three. This is a thin and light notebook with integrated Intel graphics, and I love thin and lights. They're portable. There's this one, there's this one. This one can work as a notebook or a tablet. It's super lightweight. But, like many people, I had to make the decision between portability and gaming performance. Not anymore. Here it is running Bioshock Infinite at 1080p, 30fps. This is wirelessly, and the experience isn't perfect, but if you have a USB to Ethernet adapter, even this one right here, a dual-core Ultrabook, was able to stream at 1080p, 60fps. Very, very impressive. Now, we're getting into experimental territory. Demo number four is iFinity, 3x1080p. It didn't work with lots of games, and it was more of an exercise in pushing the limits rather than trying to deliver a great gaming experience, but it worked. It's not fantastic. Latency feels noticeably higher, and the frame rate, especially when moving around consistently, can't go above about 20fps, which is interesting because we're at three times the resolution of 1080p, so being only able to achieve 20fps or one-third of 60fps, the maximum allowable value in the Valve settings looks like it may be an artificially imposed limitation, one that Valve could unlock in the future by giving us higher bitrates for higher resolution streaming. The grand finale, our most elaborate test setup yet, we have two 4K TVs, one with our Radeon R9 290X gaming machine, and the other with my pretty run-of-the-mill, I mean, it's a GTX 670, so it's pretty decent, but this is with my Steam machine. You can see they're connected. NCIX was generous enough to let us come and tear apart two stores to get access to these two 4K TVs, run Ethernet cables between two neighboring stores, but we are pretty much ready to find out if this is going to work. So we are setting, we are limiting our resolution to the desktop resolution, which happens to be 3820 by 2160, so that's 4K, which obviously isn't a setting that we can actually, you know, set here. So we're going to set our bandwidth to unlimited, our frame rate to automatic, and we're going to find out if this works. I've been working on this for about an hour and a half, trying to get this set up. So let's fire up Portal 2 and see if it flies. Not defeated yet, but we discovered an issue, and that is that the Nvidia graphics card in here with the Linux drivers that it has to run, because this is running Steam OS, does not support a 4K output over HDMI yet. So we switched to a Windows machine. We tried to use Mini DisplayPort to active dual link DVI to HDMI, and it showed up as a selection in the resolution options, but then the TV spat that out, so conveniently we're at NCIX, and we have another notebook sitting right here, and we are now installing Steam. We're running at 4K on that one, so we're going to find out if this is actually going to work very shortly. It's working! Actually, we shot in the dark. We went and fired up Batman, and it's working, capturing 3840 by 2160 at around 20, oh my goodness, it just dipped down to 14 frames per second. Now, something I'm a little bit concerned about is the link utilization here. It's telling me 21% of estimated, and it's not going above 100 megabit per second, so I'm wondering if we might have a slower than gigabit connection for some reason, if we might have a bad ethernet cable or something like that, but I'm going to go ahead and confirm these changes, and we are definitely running at 4K resolution. Now, the bitrate is not really enough to sustain it properly, and you can tell it's quite blocky, but in terms of sheer resolution, it's running. So there you have it, guys. Batman Arkham Origins running in 4K over the network using Steam in-home streaming. Is it a perfect experience? Absolutely not. It's laggy as all balls right now, and the low bitrate, so it's about 32 megabit, even when we're maxing everything out, we're running at 4K, it makes it look not nearly as good as if you're actually sitting right in front of it, but the fact that it works at all just shows such promise for this technology in the future, and when you consider as well how functional the 1080p version is and how low latency that is, and how we're going to see better network connections and faster processors on either side in the future, I think it is just so exciting, and there's so much promise for this technology. So thanks, guys, for checking out our Steam in-home streaming video. Don't forget to subscribe to Linus Tech Tips for more unboxings, reviews, and other computer videos, and thanks again to NCIX for letting us come in here and borrow their two 4K TVs to try this out. Thanks for watching.