Microsoft is certainly marching to the beat of its own drum with the Surface Duo. In a world of cookie-cutter slab smartphones and cutting edge foldable display devices, Microsoft is slapping two transitional smartphone screens next to each other and pushing dual-app usage as the way to use its first-ever self-branded Android device.
Something lost in the initial news shuffle is that the Surface Duo is actually one of the thinnest smartphones ever made. The mid-2000’s misguided obsession with thinness resulted in a few gimmicky devices labeled the “world’s thinnest smartphone.” The high point (low point?) of the thinness war was the Vivo X5Max, which had an astounding 4.75mm thickness (and would you believe it still had a headphone jack?). Last week, Microsoft published the Surface Duo specs, and the company just casually listed “4.8mm” as the thickness of the device when open. When you plug the Surface Duo in to charge it, the USB-C plug will be thicker than the body of the device.
CNET recently got a look at the internals of the Surface Duo via a non-functional, transparent prototype, and the photos and video shows just how far Microsoft went in its fanatical dedication to thinness. The Surface Duo has what looks to be a single-sided motherboard. All the chips are on one side of the board, and the presumably smooth back looks to be pressed up hard against the back of the device.
The one-sided board construction means the, uh, surface area of the Surface motherboard is absolutely massive. The right half of the device is nearly all motherboard, and chopping the photo up in an image editor shows there’s actually more total area dedicated to components than to the battery. It really is amazing how big the motherboard is, especially when you consider the only extra components in the Duo are the extra screen and wires connecting the two halves. You could argue the Duo actually has a fewer components than most smartphones, since there’s only one camera in the entire device.
Double-sided circuit boards are common in most devices, and many smartphone manufacturers have started stacking circuit boards on top of each other, giving them three or four planes to place chips on. Minimizing the motherboard surface area as much as possible leaves more space for battery, and if you look at a teardown of a modern smartphone, you’ll see only the tiniest scraps of area reserved for the motherboard, which is now a dense little chip sandwich.
Thinness is going to be a key component of foldable smartphones, since folding a device in half means doubling the normal thickness. The Galaxy Fold 1 perfectly explains this problem. Unfolded, it’s a pretty normal 7.6mm thick smartphone, but fold it in half and add a bit more for the hinge mechanism and you get a 17.1mm brick that you’re definitely going to notice in your pocket.
Microsoft says the Surface Duo is not a secondary device, and it wants people to “rethink how they want to use the device in their pocket.” Thinness is a key part of pocketability, but it seems like Microsoft got a bit of tunnel vision in the process. When folded, the Surface Duo might be extremely thin, but it is also extremely wide. At 93mm, the phone is 10mm wider than one of the widest Android phones ever, the Nexus 6. The Nexus 6 was deemed too wide by most people, given how quickly Motorola retreated from devices of this size. It limited your mobility due to having to fit in your pocket—if it even could fit in there. I am not sure building a device with the profile of a salad plate is the best approach to pocketability.
No one has spent any significant time with the Surface Duo yet, but the phone ships September 10.