The Newest PC Form Factor is a Backpack?

Are VR gaming backpacks a new trend in gaming, or just another enthusiast product few will ever use?

Three huge names in computing - Zotac, HP, and MSI have now all announced their own versions of VR gaming backpacks. HP is a huge name in computing today, and the largest among the three companies represented here. However, being the last of three to announce their backpack machine, it would seem they believe this will become a gaming trend. I, however, am not sold on the concept in its current state.
First things first: What's the big idea here? VR gaming on a desktop is already possible with the ability to move around, right? Well, yes. And the HTC Vive will work in a 15 square foot area around the user despite its cable tether, as shown in Zotac's video below. The issue is that users can't see around themselves in the real world while immersed in VR, and thus are at risk of tripping on the cord. This backpack PC idea is a way to work around that problem. However, there is some more to be said about the fact that these products are debuting in late April and May, a couple months after the release of the Vive and Rift: This idea isn't new.

At CES 2016 in January, Aorus, a totally different company came up with a way to strap a gaming laptop on your back and use it for VR. Here's a video showing their solution for use with prototypes of the Rift. VR capable gaming laptops exist now, and they have since the release of the two major gaming headsets. This begs the question, why develop a PC that is so single purpose when there are already ways to use a powerful laptop?
My best guess is to take full advantage of the space a backpack provides. While Zotac seems to have gone the route of taking a pre-existing product and shoving it into a backpack, similarly to Aorus's solution (although they are using a mini desktop PC instead of a laptop), they still benefit from using a form factor that isn't half battery, keyboard and display, and instead can optimize the cooling system to support proper desktop-class hardware. Zotac doesn't specifically mention which of their PCs it is that they used since the term ZBOX covers 8 separate product lines, but my best guess is their self-proclaimed 'most powerful mini PC', the Magnus.

It could be the Magnus EN980 Plus. Image courtesy of Zotac.

The Hardware

HP hasn't provided a report on hardware, but the Zotac Magnus has a Core i5 processor and a GeForce GTX 980 graphics card, while the MSI backpack contains a Core i7 and a GTX 980. The 980 is basically the top of the line card available for now, and either a Skylake i5 or i7 makes either of these systems more than capable of running VR quite well, provided they are cooled properly. In laptops, however, that's extremely hard to do. Even stripped down mobile versions of the GTX 980 in laptops usually require cooling systems with massive price premiums, easily costing $2000 to $4000 or more versus the $1500 or so that an equivalent desktop could cost. Using a larger platform with no included display would allow for adequate cooling of the desktop version of the card. This means no big price premium for the cooling, no added cost of a display, and, crucially, tons of space for batteries. That said, the batteries themselves might get quite expensive at this kind of scale. Time for math!

The GTX 980 is the most powerful graphics card on the market, for now... Image courtesy of NVIDIA.

Battery Life

HP is the only company to have announced their projected battery life of one hour, but they're also the only company to refuse to announce their hardware. I'll give then the benefit of the doubt and say 1 hour is reasonable. Zotac's ZBOX Magnus has the lowest power requirements of the hardware sets announced, so I'll also use their power consumption figures in determining what capacity batteries are needed to run the system for an hour. The Magnus's specs tell me it gets power from two 180W power supplies. This seems suspiciously low to me considering the GTX 980 itself is rated at 165W but reports say that it draws far more under load up to 300W, and it's recommended to have a 500W power supply with it in a system. Intel's Skylake i5 6600K has a TDP of 91W. Add in an SSD and Mechanical hard drive and we're probably talking about a ballpark power usage of nearly 360W. I'll be generous and assume it's just 325W because Zotak's system would probably melt if it were much higher for extended periods of time.
325 Watts for one hour is 325 watt hours, so we have a good idea of the capacity we need for this. Assuming LiPo batteries are in use, we're talking about one hell of a battery pack. My hobbyist needs led me to HobbyKing, which sells LiPos for very good prices. If I was making a production model, however, I would go for bare cells and assemble a custom pack instead of buying a premade pack to save some cost over the prices I could find outright. The ballpark estimate is still fair, and the weight estimate is bound to be very close.
The Zotac machine has two 19.5V 180W power supplies, so that means I need 6S minimum packs to power it, with around 15000mAh or more for total capacity. Hobbyking sells this 6S 20000mAh pack for about $130 (if you stare at the page for a while, a "one time offer" pops up every time) plus maybe $20 shipping charge since it weighs 2.5 Kg. If I ever decide to build an e-bike, now I know what to power it with. But I digress... This means that we get about 440 watt hours for about $150, which equates to about an hour to an hour and a half of play time.

You're going to need a lot of battery power to sustain VR. Image courtesy of Hobby King.

HP claims an hour of battery life plus hot, swappable batteries; and at least two will come with the system, which means the added cost on top of the PC itself is a minimum of $300. Honestly, I was expecting more, but there's still the matter of HP saying their system will weigh 10 pounds and about half that weight is batteries.
The biggest issue is probably the fact we are dealing with batteries at all; VR is all about immersion. If you need to stop even once to swap out a battery pack, and especially if that is every hour... Even worse: If you need to stop gaming and wait five hours for the batteries to charge before getting back in, that is the true menace here. I can't imagine any gamer willing to spend over $3000 for VR gaming who is willing to put up with that. I would expect at least three hours of game time uninterrupted, but then we're talking about another 15 pounds added to the pack, which is borderline painful when added to the 8-15 pounds of computer and backpack. While wearing a bag for a little while between classes with 20 pounds of stuff in it may not be an issue, wearing it while immersed in a game, standing and turning on your feet for over an hour, I can't imagine being too much fun.
I might be willing to forgive all of that if this actually allowed you to be free to move around your house while you game, but you're still restricted to that same 15 square foot zone because of the spatial tracking limitations of the Vive itself. Ultimately, this is a toy for a niche within a niche crowd, and I can't see if being practical at all, especially considering that there are many wireless headset options for VR coming out that will make this utterly pointless like the Sulon Q. Personally, I believe the future of VR lies in a device like that, instead of a glorified laptop worn on your back.