With smartphones, does thinness really matter?
This article may contain personal views and opinion from the author.
Of course, while Apple is always looking to make its products thinner and lighter, this isn't something solely coming out of Cupertino. Every few months we hear stories about the newest device that has taken over the title of "the world's thinnest smartphone". The latest one was the Vivo X3, which measures just 5.75mm thick, but there were plenty that have aimed at the same crown, like the Huawei Ascend P6 (6.18mm), the Alcatel One Touch Idol Ultra (6.45mm), the Sony Xperia Z Ultra (6.5mm), and more. You'll notice that of the devices on that list, the only ones from (arguably) top-tier smartphone manufacturers are the Ascend P6 and Xperia Z Ultra.
*Side note* For this discussion, I am referring to Samsung, Nokia, Apple, LG, Lenovo, Huawei, ZTE, and Sony as the "top tier smartphone manufacturers", because the first three have the global market share numbers to back it up, and the last five either have huge market shares in specific regions, or are on the rise globally.
In general the top tier smartphone manufacturers don't really pride themselves on making the thinnest smartphone possible. Each will obviously use the fact that a device is "thinner and lighter" than the previous generation flagship as a marketing point, but most (aside from Huawei) make an active run at the title of the "thinnest smartphone in the world". This realization alone makes the rumor about the iPhone Air a bit hard to swallow, although it can't be put out of the realm of possibility because of how much Apple loves to wow consumers with its industrial design prowess.
Industrial design skillz!
And really, that is why manufacturers feel the need to constantly be pushing devices to be thinner and thinner - it is industrial design masturbation. After an initial "wow" factor when consumers first see the pictures of a super-thin phone, no one really seems to care except for other manufacturers who see it as a new target. The real reason why manufacturers aim to make devices thinner is because it strokes their design egos.
If you can make a device that's the thinnest in the world, it must follow that you are a good hardware company, right? Similarly, if you can make a device that is just as thin as last year's model, but offers a bigger screen or bigger battery, once again that's style points for your team. This has become a staple of Apple marketing over the years, but most of the time it doesn't mean all that much. The weight difference between the iPhone 4S (140g/4.94oz) compared to the iPhone 5 (112g/3.95oz) was impressive, but one ounce isn't going to matter that much over the long haul, and it certainly isn't something you'll notice after the first few days using a product.
Much more impressive was the size drop between the iPad 4 and iPad Air. There is no arguing the amazing industrial design feat that Apple pulled off there, because it was able to take a device that was 662g (23.35oz) and shrink it down to 478g (16.86oz). Of course, given that the iPad hadn't changed size or shape much in the almost three and a half years from the original iPad launch to the iPad Air, one could certainly argue if Apple couldn't have incrementally made the tablet smaller rather than doing it all in one shot. But, delaying progress in order to have a bigger reveal impact when something is changed is a big part of Apple's marketing playbook. Ultimately though, the size and weight of a tablet is much easier to change, and leads to more appreciable differences than with a smartphone.
If you take a look at actual high-end smartphone sales, by far the most popular are from Samsung and Apple, although for comparison we'll toss in the flagships of other companies. Looking at the flagships that get the most attention (though not necessarily the most sales), you'll find the Samsung Galaxy S4 (7.9mm), the Galaxy Note III (8.3mm), the Apple iPhone 5s (7.6mm), the LG G2 (8.9mm), the Google Nexus 5 (8.59mm), the HTC One (9.3mm), the Sony Xperia Z1 (8.5mm), the Motorola Moto X (10.4mm) and the Nokia Lumia 1020 (10.4mm). Clearly, high-end manufacturers mostly aim for other considerations in design rather than thinness.
The downside to being thin
Just like there are problems that arise from being to fat, so too are there issues with being too thin, and manufacturers seem to realize this, which is why most don't really aim for that title of being the thinnest. In general, manufacturers will try to be smaller or thinner relative to a previous model, if it helps marketing; but, usually there are far more considerations at play and thinness takes a back seat. This happens because if you actually intend to sell a lot of phones rather than just get some media attention, a device that is too thin has more drawbacks than it does benefits.
Foremost on that list is battery life. It's just a simple fact: the thinner your device is, the less space you have for your device's battery pack. If you check our comment threads, any device with a battery that has a capacity of just 2000mAh is considered a complete failure by many of our readers (regardless of how that battery may actually perform, because obviously numbers trump real world usage); and, a 2000mAh battery is exactly what you'll find in the Vivo X3 and the Huawei Ascend P6. Sony was able to fit a 3050mAh battery in the Xperia Z Ultra, because the device overall is enormous with its 6.4-inch display.
On Android devices, you need the right hardware and software to make that size battery get you through a day, although Apple and Windows Phone devices can make it work with 2000mAh (Nokia Lumia 1020) or less (any iPhone). Apple has been able to make the iPhone 5s work well with just a 1570mAh battery using a combination of hardware (smaller displays use less power) and software (multitasking restrictions and impressive system-level optimizations). Making the iPhone 6 (or iPhone Air) a measly 6mm thick would only be possible assuming the display size gets bigger as per recent rumors, but it's unclear if Apple would be able to get that thickness and still have usable battery life.
Undoubtably, Apple would want to keep the overall footprint of an iPhone with a larger display relatively close to the current size of the iPhone. Apple has a history of doing impressive things with batteries. For example, the iPad mini 2 has a battery that is 6471mAh compared to the original iPad mini which featured a 4490mAh battery, but Apple only had to add .3mm of thickness to the device to achieve that much bigger battery. But, making the iPhone that much thinner, while only making it a bit larger, and adding a larger battery is a very tall order.
The best comparison in terms of display size and device footprint compared to the iPhone is the Motorola Moto X. The Moto X has almost the same footprint as the iPhone 5/5s, but as mentioned before the Moto X is 10.4mm thick at its largest point in order to fit a 2200mAh stacked battery and to improve ergonomics. To make a device that size, but just 6mm thin would mean you wouldn't be able to fit that big a battery. And, with a larger display, which would likely be much higher resolution so Apple can keep its "Retina" marketing going, all the optimizations in the world wouldn't get you the same battery life as you'd find on an iPhone 5s, because it takes a lot of juice to push that many pixels.
The other big issue is ergonomics. I can certainly imagine a possible "iPhone Air" that has tapered edges that get down to 6mm at their thinnest point, but the meat of the device would still need to be much thicker in order to pack in as big a battery as possible. Also, a device that is the same sub-7mm thickness all the way through might not be all that comfortable in the hand. That's the trick that makes the Moto X so comfortable. If you were to look at the spec sheet alone, you'd see that the Moto X is 10.4mm thick, but that's at its bulkiest point in the center. The device is curved and tapered, so at the edges it is a mere 5.6mm thick, giving it a much nicer feel in the hand (and one that had me sold the second I touched it).
Thin for thinness' sake is the domain of the rumor mill and of certain products which have the sole aim of getting a lot of attention for a short period of time. In the real world, users and manufacturers have quite a lot of considerations that go into buying or making a great smartphone. To a certain extent, sure how thin a smartphone is will make a difference. If you're trying to choose between two devices that are very similar, but one was thinner and lighter, that might sway your vote. But, it is actually extremely difficult to find a time where that would be the case.
In most cases, there are tons of other features that come into play when making that decision. Consumers and manufacturers alike are much more likely to consider build quality, camera quality, performance, battery life, overall size, and price well before considering the thinness of a device. So, maybe a better question is: why does the tech media care about thinness so much? Sometimes, it will boil down to it simply being a slow news day, or an easy headline (as with the ongoing "thinnest smartphone" competition that no one really cares about). Sometimes, it is because the rumor mill needs to be stirred up a bit (as is the case with the iPhone Air).
At the end of the day, we all have better things to be concerned with, and Apple does too. No doubt, Apple will aim to make the next iPhone thinner (at least at the edges) in order to compensate for the overall larger size that would come with a larger display. But, if you actually stop to think about it, it doesn't make much sense to aim for an arbitrary size, like 6mm thick, because there are too many other factors at play.