Back in September, Apple (NASDAQ:AAPL) launched not one, but two new smartphones. The first was the 4.7-inch iPhone 6, which is the direct successor to the iPhone 5s. The second, and for this discussion the more important one, is the iPhone 6 Plus. This is a 5.5-inch "phablet" that includes a higher resolution display and optical image stabilization. The operating system, too, takes good advantage of the larger screen.
One thing that Apple didn't do, though, is give the iPhone 6 Plus a beefed up set of internals. It still sports the same one gigabyte of memory that the iPhone 6 features, as well as the same A8 system-on-chip. I believe that, in the future, Apple would be wise to develop, much in the same vein as the "AX" chips for the iPads, a separate processor for the iPhone "Plus" family.
More processing power would be welcome
The iPhone 6 Plus features a 1920-by-1080 pixel display, which means that the on-board graphics processor needs to render a far larger number of pixels than the 1334-by-750 pixel display. For most tasks, the A8 seems to have no issues driving both the iPhone 6 and the iPhone 6 Plus.
However, for sophisticated 3D games, using the same graphics processor for both a lower-resolution display and a higher-resolution one doesn't make sense. This need for more graphics horsepower for rendering complex 3D scenes on a high resolution display is likely why Apple provisioned the A8X chip found inside of the iPad Air 2 with a substantially faster graphics processor than it did the A8. It follows that future iPhone "Plus" phones would benefit from more powerful graphics processors.
Yet another selling point, and reason to buy up the stock
If the large iPhones included meaningfully faster processors than their smaller counterparts, this would be yet another selling point used to help drive a richer product mix for Apple.
Given the kinds of volumes that Apple ships of its iPhones -- and given how unexpectedly popular the iPhone 6 Plus seems to be -- the development costs of a specialized chip for future large iPhones would essentially be lost in the noise. On the other hand, the benefits of the higher performance, particularly in convincing users to go for the iPhone "Plus" rather than the standard iPhone, could be substantial.
It can go beyond chips
Given that Apple sells the "Plus" line of iPhones for a $100 premium to the standard iPhones, the company likely has quite a bit of room to pack more features in while still maintaining a good cost structure. In addition to an improved processor, Apple could also start including higher resolution cameras, as well as more memory, more sensors, and so on.
In other words, while Apple needs to be careful to preserve its margins on the mainstream iPhone, it likely has the freedom to tastefully pack in more device-level features into the "Plus" variant of the iPhone.
On top of that, Apple showed that it is willing to add iPhone 6 Plus-specific software features, such as the "dual pane" mode in apps like Mail. At some point, I wouldn't be surprised if Apple introduced its own take on the multi-windowing support found on a number of Android tablets and smartphones as an exclusive to the "Plus" line of iPhones.
This is all good for Apple
I have a lot of faith in Apple's engineering teams to make sound technical decisions. Given the higher price point that the company can command with its larger iPhones, there seems to be a lot of room for Apple to make the "Plus" line of phone even more premium than it is today. I think investors and consumers alike will begin to see Apple take full advantage of this opportunity in future phone iterations, which should help drive an even richer product mix and market share gains against the Android camp.