The 64-bit A7 processor found in the iPhone 5S has a bright future, even if the benefits aren't immediately clear. But what are some of the drawbacks of the shift from 32-bit to 64-bit?
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What 64-bit means for the future of the iPhone (and why it could make the iPhone 5C a bad deal)


For a phone that could easily be mistaken for last year’s iPhone 5, the iPhone 5S crams some major hardware updates into that familiar frame, not the least of which is the move toward 64-bit architecture with the new Apple 7 processor. This means a version of iOS 7 with native 64-bit support, but how does that translate for the future of the platform?

Let’s start by figuring out why a 64-bit processor might be desirable for smartphone users. Breaking it down to the most rudimentary explanation, 64-bit allows a processor to crunch much larger numbers than its 32-bit equivalent. That is, it does so in a more efficient way thanks to an increased number of registers. This means the processor itself can handle higher loads before doubling down on computation or shifting some of the information being processed to the device’s RAM.

A processor that can handle more upfront means a smartphone needs fewer specialized components to handle things like WiFi, 4G, Bluetooth, and GPS input. At the very least, it should need to communicate with these components less frequently. It adds up to both faster processing and greater efficiency. Greater efficiency could have wondrous benefits for battery life, among other things.


So we can understand why 64-bit has its benefits for those going out to purchase the iPhone 5S on launch day (and, believe me, there is much more to it than my simple explanation above), but what does it mean in the long run?

The iPhone 5C, which was announced alongside the iPhone 5S, is a 32-bit device. This means Apple will support both 32-bit and 64-bit architectures for the at least the next couple of years.

And the apps we use? Right now they are optimized for 32-bit, and they will continue to be as developers will need some time to optimize their wares for a 64-bit platform. That’s all fine in the short term. 64-bit can handle 32-bit applications just fine, and given the power of the iPhone 5S’ A7 CPU there is little rush to move toward 64-bit support right away.

But over time this will change. Future iPhone models will most definitely be based on 64-bit architecture. Apps will begin to launch with 64-bit versions as the default. 32-bit will be phased out of the ecosystem. And what happens over the next few years might give you reason to pause when considering which current iPhone model to purchase.

As long-time Googler and recent Yahoo hire Jean-Baptiste Queru notes, the shift to 64-bit could mean the iPhone 5C has a “useful life” that is shorter than that of the iPhone 5S. What that means is that in a future where 64-bit takes over, there will come a time when Apple ceases support for 32-bit devices. Whether that’s two years from now, three years, or ten, we can’t say.


It’s possible that most iPhone 5C users will have upgraded to a 64-bit device by the time Apple ends 32-bit support, but in principle, the iPhone 5S makes the smarter buy. It will be supported at least a year longer than the iPhone 5C (based on past iPhone release cycles).

For an equivalent to this predicament, we don’t need to look far. The move to 64-bit iPhone architecture is much like the move from PowerPC to Intel processors for Mac hardware. Apple supported PowerPC as long as it made sense, but eventually owners of older Mac computers (which arguably have a longer lifespan than most smartphones) were knocked out of the update tree.

A similar fate awaits the iPhone 5C (as well as the iPhone 5 and iPhone 4S, or any past iPhone model, for that matter), and therefor might not be a smart buy for those that don’t upgrade their smartphone on the normal two-year cycle (or more frequently). It’s a precarious time to be an iPhone buyer, as we are at the beginning of a major shift, just as it was for laptop buyers around the time that Apple started moving to Intel processing.

Do all the benefits of 64-bit justify sending the extra cash on the iPhone 5S? All thing considered, the answer is quite apparent to me. Despite a higher price tag, it more than pays in the long run to avoid skimping up front on the iPhone 5C.

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