Technology explained: here's how the A8 chip makes the Apple iPhone 6 click and tick


Although certain aspects of it are still shrouded under a bulky veil of secrecy, Apple's newly-designed 64-bit A8 SoC surely deserves some attention, as it's the heart that churns the gears of the newest iPhone duet, the iPhone 6 and the iPhone 6 Plus. Being arguably the most important hardware aspect of nowadays' smartphones, a SoC might either “make or break” a given device, thus the gradual evolution of the silicon inside a smartphone is one of the more important upgrades.

Several days ago, Tim Cook took the stage and unveiled the newest iPhones, which are unsurprisingly being powered by the newest Apple SoC – the aforementioned Apple A8. It is a successor to the A7 one, which churns the gears of the iPhone 5s, whereas the latter's toned-down variation relied on the A6 chip. This year Apple has taken a tad more different approach and has equipped both of its new champions with its latest silicon. We already gave you an in-depth look of the improved display of the iPhone 6, but now we decided to take a closer look at the A8 SoC and find what makes it such a "core" aspect of Cupertino's newest products.

Apple A8's CPU and manufacturing technology

Apple and Samsung, the two mighty "frenemies", have previously collaborated on a number of iPhone devices, as the South Korean-based company has manufactured a number of processors in behalf of Cupertino, but the A8 chip has nothing to do with Sammy. Apple tried to divorce Samsung and replaced the latter with TSMC (Taiwan Semiconductor Manufacturing Company), which is the manufacturer behind the A8 SoC. Well, rumor has it that Samsung might get back on the bandwagon in 2015, but it's out of the picture for now.

Although Cupertino has not disclosed any official information about the clock rate of the A8 chip, some preliminary benchmark results claim that it comes with a second generation dual-core Cyclone processor on board, probably ticking at 1.4GHz (as a comparison, the Apple A7 SoC also comes with a dual-core CPU, humming at a tad lower clock rate - 1.3GHz). Apart from the speculations, we know for sure that the processor in the A8 SoC question is once again based on the ARMv8-a architecture, which makes it a 64-bit one, just like the A7 one in the iPhone 5s.

TSMC has, in fact, produced a worthy successor to the A7, at least on paper. The Apple A8 chip is built on an “advanced 20nm process”, which means that the on-board transistors of the chip are more miniature and more densely-packed than in the A7, for example, which is based on a 28nm manufacturing process. TSMC explains that the A8 is 30% faster, 25% more energy efficient, and 1.9 times more dense than other systems-on-chip that rely on the 28nm technology. Interestingly, Samsung's direct iPhone 6 contender, the Samsung Galaxy Alpha, is equipped with a homebrewed Exynos 5430 SoC, the world's first smartphone SoC based on the 20nm process.

Apple, on the other hand, says that its A8 chip is 50% more more efficient that the previous generation, the A7. Despite being slightly smaller, the A8's processor has some two billion transistors inside, roughly two times more than the ones in A7's CPU. During the keynote on September 9, the Apple A8 SoC was lauded as being 50x faster than the one in the very first iPhone, but this comparison was a pretty long shot. 

Apple A8's GPU



During Apple's official announcement, quite a lot of time was dedicated to the graphics-processing capabilities of the iPhone 6 and the iPhone 6 Plus, which will most probably allows their users to entertain themselves with some pretty eye-watering and smoothly-running games. This will be possible thanks to the graphics co-processor inside the A8. Although Apple mum's the word, we are most probably dealing with a PowerVR GX6650 GPU unit. It has some six USCs (Unified Shading Clusters), based on PowerVR's own Rogue architecture, and the whopping 192 cores. Apart from being a top performer in graphics chewing, the PowerVR GX6650 is also one of the manufacturer's most power efficient GPUs.

The graphics processing unit found in the iPhone 5s was also manufactured by PowerVR (a PowerVR G6430 one), but we'll have to wait for some graphics benchmarks between the iPhone 5s and the iPhone 6. Apple also didn't give any statistical data about the performance of the GPU in the Apple A8, yet only claimed that its performance is no more or less than 84x times higher than the one of 2007's Apple iPhone.

However, we found that while the iPhone 5s' GPU (the PowerVR G6430) accounts for 153.6 / 230.4 GFLOPS at a 600MHz clock rate, the PowerVR GX6650 runs circles around it with 250/500 GFLOPS at 650MHz - at least on paper, the iPhone 6 is a much better graphics-munching beast in comparison with its predecessor.

Paired with Metal, a new technology that allows the CPU and the GPU of the A8 SoC to work even better together and produce even better real-time graphics, we can assume that gamers will by no means be disappointed about the graphics' performance of the new batch of iPhones.


Apple A8's motion co-processor - meet the M8


The iPhone 5s was the first Apple smartphone to come with a co-processor that assists the main CPU in gathering motion data - the M7. It collects information from a slew of on-board sensors, such as gyroscopes, the accelerometer, the compass, etc., on behalf of the main CPU in the A7 SoC, which further improved the power efficiency of the device. The Apple iPhone 6 and iPhone 6 Plus continue this trend, as their A8' SoC comes with an M8 co-processor.

It's an improved version of the M7 co-processor in the Apple A7 SoC - it comes with a new, further-enhanced barometer (for even better air pressure monitoring), and now strips the A8 from even more functions, which include step-counting, various elevation changes, and overall distance traveled. It is also used to sense whether you're stationary or on the move. Thanks to the already-mentioned Metal technology, M8 co-processor is also used in concert with both the CPU and GPU when you are playing games, so that it can detect the iPhone's orientation - another de-burdening of the A8. 

These functionalities of the M8 co-processor pave the way for HealthKit's unobstructed work. HealthKit is Apple's take on the trendy-of-late monitoring of fitness activities and health data. Normally, the SoC would have been the workforce behind HealthKit, but this might not have a positive effect on the battery life. Fortunately, the power-efficient M8 co-processors is in charge of these wellness-centric functionalities. As sound logic suggests, this will surely help the iPhone 6 and iPhone 6 Plus save some battery life here or there.


Apple A8 and the iSight camera


A lot of time was dedicated to the improved iSight camera of the iPhone 6 and the iPhone 6 Plus during the keynote at September 9. Apart from the improved hardware, Apple revealed that the camera will benefit from the raw processing power of the A8 SoC even more. This will happen thanks to a newly-designed video encoder and an improved image signal processor that are on board the A8 silicon. Thanks to them, iFans will be able to make use of new fancy features, such as Focus Pixels, a better face detection and continuous auto-focus (which is a phase-detection one). The seamless collaboration between the Apple A8 and the iSight camera will also produce images with less noise and, naturally, better overall quality. The newly-implemented 240fps slow-motion video-shooting mode is most probably also courtesy of the collaboration between the A8 and M8 goodnesses. 

Apple A8 and battery life

All in all, we took a deeper look at the new features in the A8 SoC, save for one, arguably the most important to the ordinary user. We are speaking about battery life, the Achilles' heel of almost any smartphone. Despite the deep optimization between hardware and software, the iPhone 5s with its 1570mAh battery was not among the top-performing champions when it comes to battery life. Well, we still can't say with certainty if the iPhone 6 and the iPhone 6 Plus will be miles ahead of it in terms of battery efficiency, but we can speculate, based on the bits of information that Apple has officially provided us with.

While we took a deeper look at the Apple A8, you may have noticed that we repetitively used a given word in most of the paragraphs - "power efficiency". Starting from the new 20nm manufacturing process of A8's CPU, moving on to the more powerful, yet more efficient GPU, and concluding with the battery-friendly M8 co-processor, it becomes apparent that Cupertino has decided to amp up the game of the iPhone 6 in the battery life department. If we consider this allegedly-improved overall power efficiency alongside the bigger, 1800mAh battery of the Apple iPhone 6, we can expect Cupertino's newest flagship to have a much better battery endurance. The iPhone 6 Plus, with its more-than-adequate 2915mAh battery, will most probably deliver as well.



reference: AppleTSMC, PowerVR (1), (2), AnandTech

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170 Comments

1. Mxyzptlk unregistered

Most advanced mobile system in a nutshell

2. ShenAlJoker

Posts: 113; Member since: Jul 19, 2013

Are you NUTS??????

4. Mxyzptlk unregistered

Just a little ;-)

63. Duketytz

Posts: 534; Member since: Nov 28, 2013

Or sarcastic.

93. InspectorGadget80 unregistered

He's delusional. Every iphone have dual core.

127. Mxyzptlk unregistered

So does the Moto X. Your point?

133. Shatter

Posts: 2036; Member since: May 29, 2013

If you want a single out a single phone than I choose the octacore exynos note 4 or any Intel quad core 64bit phones. Both make your iPhone look like a toy.

145. Tommy1960i

Posts: 144; Member since: Oct 11, 2013

the same game with the same graphics runs on dual core CPU on iPhones and on a quad core CPU on android. iOS has far better optimizations.

30. WendyFromCircus

Posts: 40; Member since: Sep 02, 2014

Frandroid still stuck in a opengl nutshell, while we enjoy metal gaming system :)

33. PapaSmurf

Posts: 10457; Member since: May 14, 2012

Tegra K1 smacks the A8 in Graphics still so no.

66. Duketytz

Posts: 534; Member since: Nov 28, 2013

Typical Apple Fangirl... Go Papa I support you on this.

89. Iodine

Posts: 1504; Member since: Jun 19, 2014

It will also make you an fried bacon and eggs unlike A8.

135. Duketytz

Posts: 534; Member since: Nov 28, 2013

Have you ever tried out the nvidia shield? If not please do not say things that are not true. I played for over 4-5 hours of intense gaming on my friend's and guess what, I didn't burn my hand...

41. vipervoid123

Posts: 163; Member since: Aug 27, 2013

Android L will introduce a graphics system that is share similar function as metal

52. vJhen

Posts: 2; Member since: Sep 12, 2014

Oh.. Plastic gaming.)

157. uRiBiTo666

Posts: 55; Member since: Jun 02, 2013

B**** please you have metal. We have a device that is designed SPECIFICALLY FOR GAMING

56. strudelz100

Posts: 646; Member since: Aug 20, 2014

Pretty much. 2nd Generation Custom Core with ARMv8 instructions from ARM's new designs. Everyone else is JUST releasing their first and everyone gave up on custom cores altogether, and are just using off-the-shelf ARM cores; which never perform as well as a custom platform. Smallest nanometer process available as well. Best single core performance according to early benchmarks topping....the A7.

83. tedkord

Posts: 17473; Member since: Jun 17, 2009

That would matter if they only had single cores. As they don't, last year's Snapdragon 800 outperformed the A7 in Antutu and Geekbench overall.

90. Iodine

Posts: 1504; Member since: Jun 19, 2014

He was implying that most of apps are still running on a single core. That means iPhone would run such app more than twice as fast.

118. brrunopt

Posts: 742; Member since: Aug 15, 2013

Witch is false

114. jordan.hatch

Posts: 2; Member since: Sep 12, 2014

actually the Galaxy Alpha will be the first phone with 20nm process........"powerful Samsung Exynos 5430 octa-core chip roaring under the hood, but one interesting detail that has now slipped out was that this is in fact the world’s first 20nm high-k metal gate (HKMG) based chip on a smartphone." phonearena.com/news/Samsungs-Galaxy-Alpha-comes-wi​th-Exynos-5430-the-worlds-first-20nm-HKMG-based-ch​ip_id59339

119. Iodine

Posts: 1504; Member since: Jun 19, 2014

Of course samsung has to be first in everything, including rushing out a spec to spec copy of next Apple iPhone, 5 days before it will start selling. But honestly nobody cares for galaxy alpha, 20 nm didn't made it's promise of making the battery long lasting there. Actually a year old 28 nm SoC iPhone 5S with smaller battery lasts rather significally more.

129. Taters

Posts: 6474; Member since: Jan 28, 2013

Significantly?! Lol we don't even know if the 5s is more let alone significantly. GSM arena is the only one that had it two hours ahead. Big whoop. Oh and you care enough about it to try and downplay it. Lol 20nm hkmg process is nothing to brush aside. That's premium silicon. You ifans slay me.

60. afrohoxha

Posts: 264; Member since: Mar 13, 2014

It is a modern system, but most advanced? Have a taste of preliminary results for most advanced system: visit results.righware.com/basemark_x/all-all-phone-ios-​all

85. 5sApple

Posts: 11; Member since: Sep 12, 2014

GPU testing Basemark X suite. iPhone 6 = 21,204 points, iPhone 5s = 20,253 points Samsung Galaxy S5 = 23,501 points

109. Cicero

Posts: 1149; Member since: Jan 22, 2014

Like iphone or not this is look good on paper. This means also that all cpu/gpu manufacturers will not get lazy. Nice to have competition and further steps.

3. Commentator

Posts: 3723; Member since: Aug 16, 2011

What's the deal suddenly putting "Tech(nology) Explained" in front of these iPhone articles recently? Is this going to be a thing from now on? It seems pretty redundant coming from a site that's basic function is, presumably, to explain technology.

5. Mxyzptlk unregistered

A tech explained article on a website about phones and mobile devices, yeah what is the deal.

82. strudelz100

Posts: 646; Member since: Aug 20, 2014

They don't really know much. Either do commenters. This place is great for flame wars: Light on knowledge about tech.

94. InspectorGadget80 unregistered

It's iPA what do you expect

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