Play High End PC Games on iOS with Moonlight

Update:

Apparently the developers renamed this app from Limelight to Moonlight. I edited this piece to reflect that change.

Great news for fans of premium gaming: pretty soon, you’ll be able to play a massive catalog of high-end PC games on iOS!

First, before those of you with experience playing streamed games grab your pitchforks, there is something big to point out here: streaming gaming has come a long way in the past few years. Just recently, streaming meant low frame rates, high latency, reduced resolution, and high system requirements. AirPlay was the perfect example of this, being almost unplayable with all but a handful of games who’s designs worked in spite of high latency.

Starting last year with iOS 8, things changed. I’ve chronicled some of the ways iOS 8 was a game changing update for AirPlay, but suffice it to say, Apple managed to get high quality, relatively low latency¹, 60fps gameplay out of the A6 chip. Seriously; the vast majority of games are now perfectly playable over AirPlay. The benefits of a wired HDMI connection are minimal for all but the most graphically demanding games.

With that in mind, there are a few apps on the horizon that aim to take the opposite approach. What if instead of beaming what your phone sees to the TV, you beam a high-performance game console or gaming PC to your phone? It’s the same technology either way, and although phones have come a long way in performance, a killer gaming PC can still utterly destroy the graphics of the highest end devices available². Several apps are coming soon that aim to do just that – beam the games straight off a high end gaming PC on to the iPhone or iPad, and do it with low latency and high performance.

Enter Moonlight

The first streaming app I’m going to look at is also the one with the highest performance, and serves as a great example of streaming PC gaming at it’s best: Moonlight.

Moonlight is an open-source implementation of NVIDIA’s GameStream technology. GameStream was designed by Nvidia to allow owners of the Shield handheld console (and later Shield tablet) to stream games from their gaming PCs to their Shield devices. While the Shields haven’t quite set the world on storm³, The streaming technology Nvidia developed for them is actually quite excellent.

Moonlight brings that technology to iOS. Owners of GameStream compatible Nvidia graphics cards⁴ can stream games directly from their PC to their iPhones and iPads, just like they would be able to do with the Shields. Moonlight even allows you to control the action with an MFi controller, and does the necessary work of converting the signal so your computer thinks it’s connected to an Xbox 360 pad!

Gameplay Quality

Once you get Moonlight set up, get your PC configured correctly, and run a compatible game, the quality of the experience is nothing short of phenomenal. In scenes with minimal complexity or motion, visual quality is virtually indistinguishable from native gameplay. Compressions artifacts pop up in fast-motion scenes, but they aren’t obtrusive enough to impact gameplay; you’ll always be able to see what’s happening on screen.

More important than how it looks is how it feels, and this is where Moonlight really shines. No matter how much crazy complex action is happening on screen, Limelight always maintains a perfect 60fps frame rate. Doesn’t matter which game, doesn’t matter which iOS device you use – even a first-generation iPad Mini gets perfectly fluid 60fps gameplay. Not even AirPlay can claim this – only the iPhone 5 and above run above 30fps on the Apple TV.

Perhaps the most critical issue is latency – how quickly game responds to your movements, and how long it takes the image created by the computer to beam itself to the iOS hardware. Again, Moonlight comes out looking great here. You wouldn’t want to enter a pro gaming tournament with it any time soon, but for all but the most reaction-time-demanding games, Moonlight is perfectly playable. Latency is comparable to using AirPlay with an A8-powered device – you’ll notice it if you really look for it, but you probably won’t feel it while you’re playing. In this instance, Lightning-connected controllers fare a bit better than bluetooth ones⁵, but both are enjoyable.

Caveats

Perhaps the biggest hurdle facing Moonlight is the hardware required to use it. Obviously you need a gaming PC – this is a local streaming affair, one device to another, and you have to supply both devices. More specific than that, though, you need a gaming PC with very specific hardware: relatively solid specs across the board, and one of a small list of very-recent Nvidia graphics cards. In fact, before writing this article, I had to grab a new graphics card, because my powerhouse Radeon obviously doesn’t apply here.

Assuming your hardware is up to par, you’ll also need a high-performance wireless network, preferably with the 5GHz band. My AirPort Extreme with 802.11ac worked fine, but only with the PC plugged in directly – using the PC over Wifi caused significant audio latency and dropped frames. Even then, the signal degrades the further you get from the router. I’m able to get full coverage in my 1-bedroom apartment, but more expansive setups are going to require well-placed network equipment. Moonlight doesn’t appear to do any form of internet streaming at this time, either – you need to be on the same network as your PC, and probably not too far away.

Lastly, Moonlight is very much in beta right now. There are occasional crashes, the interface is confusing, and it often goes into a crash loop that requires the entire app be reinstalled. But with all that said, it’s still shocking to me just how well it works when it is working. You can play for hours, and not feel like you’re missing out on anything due to streaming.

Final Thoughts

Moonlight is perhaps the least ambitious form of streaming out there. You need to supply all the hardware yourself, and it only works over a short-range wireless network. Even so, Moonlight is remarkable in just how well it works. Shocking, actually. It may not do as much as other streaming services, and it may require an expensive and specialized hardware setup, but consider me sold. Streaming PC gaming is here, for real, and it feels better than I could have imagined.

Moonlight is currently in beta testing, and is scheduled to be submitted to the App Store for distribution in the near future. If all goes as planned (and if Apple doesn’t ban it from sale), expect to be downloading Moonlight – and perhaps buying a new graphics card to go with it – later this year.