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What is 64-bit? iPhone 5S A7 chip explained

The arrival of Apple’s first 64-bit smartphone has been overshadowed by the iPhone 5S’ updated camera and the colourful iPhone 5C, but it’s a big deal that has huge ramifications for every future Apple device – as well as Intel, Google, Samsung and ARM. Mike Jennings explains the technical side and the implications for future iPhones, iPads and their Android competitors.

SEE ALSO: iPhone 5S features: killer or just full of filler?

What is 64-bit and how does it work?

The term “64-bit” refers to the way processors handle calculations. It concerns the maths performed by computers at their most basic level: “bits” are tiny units that have values of either 0 or 1, and these are manipulated by the processor and written to a PC’s memory in order to complete tasks.

Smartphones that use older 32-bit processors can only work with data strings that consist of 32 characters – so they have a maximum range of just over 4 billion numbers. A 64-bit processor has a much larger range because of the increased number of digits available – data can be processed 64-bits at a time, rather than in 32-bit chunks.

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Imagine it this way: a team of 32 codebreakers at Bletchley Park try to crack the same code. It’s slow work – but double the codebreakers and it’ll be finished faster.

Or try this: you send 32 assistants to collect 128 items from the same shop. The 32 assistants will require four trips – but if you’ve got 64 assistants, they’ll only need two.

A 64-bit architecture is faster, gets more work done and is more efficient.

The 64-bit A7 processor in the iPhone 5S uses the ARM v8 architecture. It’s the first time this new chip has been used in a smartphone, and Apple claims it’s got twice the power as the A6 chip in the iPhone 5.

A 64-bit chip brings the iPhone 5S into line with the rest of the computing world. AMD and Intel have made 64-bit PC processors since the turn of the Millennium. The PS4 and Xbox One consoles both use 64-bit AMD chips.

SEE ALSO: Xbox One vs PS4

Does 64-bit bring real benefits?

The main benefit concerns the speed of mathematical calculation, which we’ve detailed above. The other big improvement concerns memory: a 64-bit chip can address more than 4GB of RAM, which 32-bit chips just can’t manage. It’s not an issue now, as no iPhone or iPad has more than 1GB of RAM, but it could be a few years down the line.

The added power of 64-bit will improve iPhone 5S performance in a number of areas. The encryption used by the phone’s fingerprint sensor will be satisfactorily fast, and the camera’s new features will also work smoothly with the chip’s improved computational ability.

These high-end applications – as well as photo and video editing and encoding, for instance – are faster with 64-bit. Games, too, benefit – at the iPhone 5S launch Apple demonstrated Infinity Blade 3, which likely wouldn’t be possible on 32-bit.

Apple’s iOS 7 has been re-engineered to work with 64-bit, and that means the OS will feel butter-smooth. But, given the simplicity of many smartphone apps, it’s a fact that many just don’t need the added power of 64-bit right now.

Most developers won’t have advance access to Apple hardware, so it’ll take time for 64-bit apps to arrive. Thankfully, the new processor is backwards-compatible with 32-bit software.

Future Apple processors, whether in iPhones or iPads, could have enough power to run console-quality games and PC-quality apps. The shared architecture could even make it easier to port software to iOS devices.

One of the key benefits right now is marketing – Apple’s the first firm to us a 64-bit smartphone processor, and that brings plenty of kudos, even if the real benefits won’t arrive for a little while yet.

What are the long-term implications?

Despite the immediate performance boost, the move to 64-bit is more important in the long-term.

In a year or two, Apple’s phones and tablets – and every competitor – should have 4GB of RAM alongside a 64-bit processor, and Cupertino’s software teams and third-party developers will have had more time to get the most out of this new architecture – an important head-start over Samsung and Google.

That expertise will have big implications: the iPhone may use more efficient chips with better battery life. The iPad could become even more powerful. Apple may have ARM processors with enough grunt to power laptops.

It ties in to Cupertino’s long-term vision for “platform convergence” – a strategy that may see phones, tablets, laptops and other devices share hardware and software.

The Apple A7 chip means the iPhone and iPad now share the same 64-bit system as Intel, and iOS and OS X already share the same kernel and developer environment. Apple claims the A7 is a “desktop-class” chip, so it’s no stretch to imagine more powerful parts inside laptops.

Apple has also taken charge of graphics: previous iPhones and iPads have had PowerVR GPUs, but this time it’s described as Apple’s own chip.

It’s not just hardware. Its OS X desktop system borrows features from iOS in every new version now and if Apple can use ARM-based 64-bit hardware across more devices, a universal store and unified software could follow.

What about demanding tasks that need Intel power? That’s where the cloud could take over. It’s a long way off, but Apple has already worked on hugely upgraded cloud facilities: in 2010 it built a data centre in North Carolina for iCloud, and reports indicate the facility only opened with 20,000 servers – despite that location having room for about one million servers.

While its data centres use Intel Xeon hardware, it should be noted that ARM-based servers already compete with Intel in some benchmarks, and AMD has ARM-based 64-bit server chips on its roadmap.

The bottom line

Apple’s move to 64-bit will make the iPhone 5S more powerful, but an obvious impact won’t be felt until developers begin to release apps that make use of the new A7 chip.

The 64-bit ARM chip and its successors will ensure that the next iPhones and iPads are barnstormers, and they could help console-quality games and PC-quality applications become more prevalent on these devices.

It’s bigger for Apple’s long-term future, though: a 64-bit processor signifies another step in the convergence strategy that could see iPhones, iPads, laptop and even desktops sharing hardware, operating system and software.

Apple is the first smartphone firm to make the jump to 64-bit but, now, everyone else will follow suit – and that’s only good news for consumers. It might look like overkill, but Apple’s move to mobile 64-bit is a crucial step for proper progress – and could point towards an ARM-based future.

Mike Jennings is a freelance tech writer. He spent five years as senior staff writer at PC Pro, and now writes about components, PCs, smartphones, tablets and laptops. He tweets from @mikejennings.

Next, read our iPhone 5S vs Galaxy S4 comparison

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