Last week, Valve announced it would be bringing Steam's long-standing in-home streaming functions to mobile platforms, letting users play games running on a PC via a tablet, mobile phone, or Apple TV on the same network. We got a chance to test out a beta version of that new mobile Steam Link app this week, ahead of today's launch on Android 5.0+ devices and an iOS launch that has been delayed "pending further review from Apple." We found that, on mobile, in-home Steam streaming is still a passable solution for playing away from your office chair, provided you have the right game and the right network setup.

The Steam Link app itself is relatively straightforward. After asking you to sync a controller (a Steam Controller or any generic bluetooth input will work), it scans the network for computers running Steam. The first time you connect to any given computer, you have to enter a four-digit code to prove the connection is wanted (and possibly install some Steam driver updates to enable the stream).

After that, you can start streaming Steam's "Big Picture" mode to your mobile device as long as the host computer is on, connected to the network, and running Steam (no remote startup options here). You can also back out to a full desktop view, if you really want to, and bring up an on-screen keyboard and mouse pointer for full control of the desktop.

Valve isn't kidding when it says a Wi-Fi router in the 5Ghz band is required for wireless streaming. I first tested iPad streaming on the low-end 2.4Ghz router provided with my Verizon FiOS subscription (an Actiontec MI424WR), with a wired Ethernet connection to my Windows gaming rig on the other end. The Steam Link network test warned me that "your network may not work well with Steam Link," thanks to 1- to 2-percent frame loss and about 15ms of "network variance," depending on when I tested. Even graphically simple games like The Binding of Isaac ran at an unplayably slowed-down rate on this connection, with frequent dropped inputs to boot.

Switching over to a 5GHz tri-band router (The Netgear Nighthawk X6, to be precise), the same network test reported a "fantastic" connection that "look[s] like it will work well with Steam." On this router, remotely played games ran incredibly smoothly at the iPad's full 1080p resolution, with total round-trip display latency ranging anywhere from 50 to 150ms, according to Steam Link's reports (and one-way "input lag" of less than 1ms). At that level of delay, playing felt practically indistinguishable from playing directly on the computer, with no noticeable gameplay impact even on quick-response titles like Cuphead.



















Even on a "fantastic" in-home network Wi-Fi environment, though, the quality of the mobile streaming depended a lot on the resolution and visual detail of the game being played. Streaming a title like the supremely underrated Super Puzzle Platformer to my iPad Air only required about 4,000Kbps of my router's bandwidth, according to Steam Link's reports, and ran without a hitch. A game like 2016's Doom reboot, on the other hand, needed more like 12,000Kbps of overhead, which led to some intermittent screen tearing and split-second stuttering at especially intense points.

Wireless range could also end up being an issue with 5GHz Wi-Fi. Playing in the same room as the 5GHz router, I was able to maintain a solid connection with only the intermittent problems mentioned above. Testing in my bedroom two floors away, though, I found the generally solid connection would often drop out completely for seconds at a time, effectively freezing my view of the game as the network struggled to catch up. When the streaming resolved itself a few seconds later, I was often lost, damaged, or dead in whatever title I was playing.

We also tested the Steam Link app on an Apple TV with both sides on a Wired Ethernet connection. Though the app's usual metrics didn't work on this version of the app, the performance seemed comparable to the 5GHz Wi-Fi, complete with regular stuttering on high-end games. Attempts to test streaming from a Wi-Fi-connected MacBook to a Wi-Fi-connected iPad failed due to Steam controller driver issues on the Mac.

Even in the best conditions we were able to test, our mobile devices weren't quite able to provide the indistinguishable-from-the-desktop "portable monitor" streaming experience we wanted in all cases. But with the right networking hardware, the new Steam Link app provides a handy, low-friction way to sneak in some passable PC gaming anywhere from the bedroom to the bathroom.