Apple iPhone 6 (Apple A8) performance review: CPU and GPU compared to the best Android phones out there


When it comes to performance and power there is no device so widely misunderstood as the iPhone. The new iPhone 6 (and iPhone 6 Plus) is no exception - you’d find bashful comments about its comparatively low clock speed, ‘only’ two CPU cores, low amount of RAM, lack of expandable storage, and what not in practically every online forum.

Looking at numbers without fully understanding them, though, is a dangerous business. This iPhone 6 performance review aims to clear some of the widespread misunderstandings and give a more detailed overview of the state of mobile CPUs, and how Apple’s efforts compare to that of the main rival: the mostly Qualcomm-powered Android fleet.

Apple A8 and ARM's architecture license


When it comes to the CPU, it’s worth starting off with a quick refresh on the facts. The overwhelming majority of mobile devices - be it Android, Windows Phone, or iOS ones - are based on ARM-derived architectures. ARM offers two types of licenses to its clients: a processor license and an architecture license.

Most manufacturers use the processor license that grants them the right to take an ARM-designed core and use it in their SoC. An example for ARM-designed cores include the battery-optimized Cortex A7 (and its newer, 64-bit Cortex A53 successor) and the Cortex A15 (with its newer, Cortex A57 64-bit heir). Phone makers like Samsung, for instance, take those two cores and combine them in various big.LITTLE combinations to come with SoCs like the Exynos 5430 in the Galaxy Alpha where the company combines four power-efficient A53s running at lower clock speeds and four performance-driven A57 that can go up to higher clocks, but also draw more battery.

The other type of licensees, those under ARM’s architecture license program, take a totally different approach by just using the ARM instruction set, while building their own CPU core. The most prominent companies that do that are Qualcomm and… Apple. Apple used to operate under an ARM processor license all the way until the iPhone 4s, but decided to switch to an architecture license for the iPhone 5, and has building its own CPU cores ever since then.

The state of 64-bit



Looking at this timing, you see how this coincides with Apple’s industry-first introduction of 64-bit chips - the first 64-bit phone, the iPhone 5s, arrived two years after Apple introduced its first processor, and Apple has clearly used this time slot to outpace the industry. To this day, Apple remains uniquely positioned in the transition to 64-bit on mobile - all first-party apps were 64-bit-ready on iOS 7 launch date, and the company has given developers an ample timeline and great tools to optimize their app quickly and effortlessly to 64-bit. With extremely low levels of fragmentation in Apple’s ecosystem (where by fragmentation we mean that iOS adoption rates are high and happen in days, while on Android transitions span months, if not years), the company is one year away from having a lineup consisting of 64-bit devices only. This will happen next year when the Apple iPhone 5 is expected to go out of production, and the 64-bit iPhone 5s with Apple A7 (or as speculated, a plastic derivative of the 5s with similar hardware) takes the lowest place in Apple’s ecosystem.

Looking over to the Android camp, we’re seeing that the platform lags behind a full year and more. To this date, in late 2014, the biggest Android vendors like Samsung, HTC, LG, and others, are all releasing their flagships with 32-bit chips like the Snapdragon 805 and Snapdragon 801. Both those chips are based on the now 3-year old Krait core (with some tweaks, of course), and later on in this article you’d be able to spot the difference in compute power. Naturally, using the 32-bit 805 translates into those flagships not being able to benefit from ART optimizations in Android L.

The earliest this could (and likely would) change is in spring of 2015 when the first wave of Android flagships for next year is expected to arrive. Some (and hopefully most) of those devices are said to feature the Snapdragon 810, Qualcomm’s first top-level 64-bit SoC. In just over a year time, Qualcomm has overhauled its portfolio to consist of 64-bit chips on practically all levels, from the low to the high-end. However, the Snapdragon 810 does not ship with a custom Qualcomm core (such a core would likely take more time for development) - instead, the company goes back to using an ARM processor license and equips the 810 with a big.LITTLE setup with four low-power Cortex A53 and four performance-driven Cortex A57 cores.

Given the long period of time it takes for the Android install base to switch to an ART-enabled version of the platform in meaningful numbers (let’s keep in mind that we don’t have a minimum target for ART, and chances are that it won’t be KitKat, but Android L), it is clear that Android is in a much less favorable position in terms of 64-bit-readiness.

Apple A8 die break-down


Being as secretive as Apple is (the company does not disclose processor details in the way Intel does) hides a little joy for us, tech reviewers, to try and reverse-engineer its efforts.

We’re not completely in the dark, though: in the past two release cycles, Apple has been disclosing the number of transistors in the Apple A8: there’s now a whopping 2 billion of them, double the number from the A7. As far as we can tell, this is the most ever in a smartphone chip - in comparison, some estimates claim that the Snapdragon 805 chip features 700 million transistors.

From here on, the journey towards a better understanding of the Apple A8 starts with a teardown of the iPhone 6 and images of the A8 die from Chipworks. Those images give us a detailed breakdown of the Apple A8 die and the location of its various components.

Despite (or rather because of) the doubling of transistor count, the die size has grown smaller and comes in at 89mm2 in the A8, down from 102mm2 in the A7. Apple has switched the places of components on the die, and the CPU is now on the bottom left (it was on the bottom right), with a large block of L3 cache above it. Despite a 20% decrease in the size of the SRAM block (cells have shrunk in third from 0.12µm to 0.08µm), it’s likely that more advanced circuitry makes up for the difference and we’re still dealing with 4MB of L3 cache memory. At the time of this writing, we have seen the first benchmarks showing that memory latency has indeed improved by a hefty 20ns when we go out to L2 $ and further.

The most drastic change in size, however, seems to be in the CPU die size: the new CPU measures 12.2mm2, nearly 30% smaller than the 17.1mm2 CPU die in the Apple A7. By all visible clues, the rest of the architecture remains the same: we have 64KB/64KB of L1 instruction/data $ (L1 is the fastest cache, located on the CPU die), and a 1MB block of L2 cache shared between the cores.

Apple has provided a few important details about the CPU performance of its new A8: first, the company says the new CPU comes a 25% performance improvement, and illustrates this with a chart showing generational improvement all the way since the 2G iPhone (the 25% number is derived by comparing the iPhone 5s’s 40x CPU overhead over the 2G iPhone and the 50x peek in the iPhone 6).


On clock speeds and deceptive marketing


With a modest boost in CPU clock speeds from 1.3GHz to 1.4GHz (an 8% speed-up), the 25% improvement obviously comes from various other tweaks and tricks. Before diving deeper in benchmarks, though, here is the place for a quick insert about clock speeds and the state of the industry. Commentators in forums are quick to point out the apparent inferiority of Apple clock speeds in comparison to the much faster speeds declared in rival Snapdragon and Exynos chips, for instance. The most up-to-date example is the Snapdragon 805 with a declared clock speed of ‘up to 2.7GHz’. At first sight, Apple’s Cyclone core looks like a sore loser with its declaration for just half that at 1.4GHz.

Most people would call it a day at this point - the Snapdragon outperforms the A8 hugely, case closed. This, however, would be naïve: running real-world applications and games shows instantly that the 2.7GHz speeds can only be achieved for a very short periods of time, but after those short outbursts, the chip quickly throttles back to the much more sane ~1.3GHz. Put simply, the 2.7GHz number that you read about is not the nominal frequency, but maxed out turbo speeds that are not sustainable for the long term. In fact, Apple is being much more truthful as it declares actual nominal (and not turbo) speeds for its chip, plus, the company goes on to disclose a second big thing about its chip: sustained performance times. Apple actually claims its A8 is capable of running flat at its nominal speeds for (at least) 20 minutes.

This is the right place to note that ARM, the licensee company for both the Snapdragon and the Apple A8 CPU cores, has actually claimed that the current generation of its processors works best in terms of thermal output/performance at around 1.2GHz. Going up above that ensues big consequences - AnandTech has earlier shared estimates that going above the 1.5GHz threshold by just 100MHz brings up a shocking, quadratic increase in voltage and power consumed by the chip.



Related phones

iPhone 6
  • Display 4.7" 750 x 1334 pixels
  • Camera 8 MP / 1.2 MP front
  • Processor Apple A8, Dual-core, 1400 MHz
  • Storage 128 GB
  • Battery 1810 mAh(14h 3G talk time)

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156 Comments

1. shaineql

Posts: 522; Member since: Apr 28, 2014

3x Bigger resolution and Samsung phones still keep up , awesome job !

2. promise7

Posts: 894; Member since: Jul 03, 2013

Moral victory FTW!

10. Mxyzptlk unregistered

Can they keep up over time though? I rest my case

12. Duketytz

Posts: 534; Member since: Nov 28, 2013

In case you aren't aware some iPhones cannot keep up with times too. Ask anyone with iPhone 4S/5 on ios 7 and you will hear lag issues

20. Switch00

Posts: 536; Member since: Sep 04, 2013

Apple basicaly destroyed my Ipad1 with IOS5 update. I'm still able to use my ZXSpectrum from the 80's in exactly the same way as on the first day, while on the other hand, the 'revolutionary' Ipad device is only good for cutting baloney on it on a hangover morning. I will be glad to show the difference between both devices to my grandkids.

32. InspectorGadget80 unregistered

With 1gb of ram and still uses dual core.

36. LetsBeHonest

Posts: 1548; Member since: Jun 04, 2013

Didn't heard any issues from 5 but 4s lags a little bit sometimes. Any way apple CPU's are great for running idevices(give credits guys they deserves it) but I think they should have increased the amount of ram.

146. Dr.Hye

Posts: 95; Member since: Apr 16, 2014

I agree with you here bud. But they should have I creased ram I don't care what their excuse is to not increase ram. More room always is better than tying to cram everything in one small room.

160. TheRabidUnicorn

Posts: 7; Member since: May 19, 2015

But they can't multitask android devices need high powered CPUs and more ram to run multiple operations at the same time. However iOS cannot multitask therefore it doesn't need good prossesors but for some reason they deside to price their phones between $750 and $950 Where as the moto g which has the same specs is $180

22. Zomer

Posts: 361; Member since: May 31, 2013

Lol, Apple makes Samsung looks like a old car.

74. EclipseGSX

Posts: 1777; Member since: Oct 18, 2011

Please elaborate how "Apple makes Samsung looks like a old car" Pretty sure cars and phones have very different yet distinct looks.

118. icrappy

Posts: 42; Member since: Sep 19, 2014

but speed between the s5 and the iphone 6 is barely noticeable despite that the s5 is running on a 32 bit instruction set

161. TheRabidUnicorn

Posts: 7; Member since: May 19, 2015

Why does apple need 64bit if they aren't putting more than 4gb of ram in their phones that's the only reason to have 64bit

42. alias3800

Posts: 62; Member since: Jul 09, 2014

...... Define "keep up."

49. ABDULGHAFOOR

Posts: 106; Member since: May 04, 2012

I am a proud owner of galaxy s4 but i will say honestly that iphones 6, 2012 specs are still batter than any 2014 smartphones

53. Tritinum

Posts: 471; Member since: May 06, 2014

batter sure (whatever that is), better? nope.

101. ABDULGHAFOOR

Posts: 106; Member since: May 04, 2012

Better* typing mistake :/

105. Neo_Huang

Posts: 1067; Member since: Dec 06, 2013

That is because the screen resolution is lower and iOS does a lot less multitasking.

162. TheRabidUnicorn

Posts: 7; Member since: May 19, 2015

In fact no multitasking at all

143. icrappy

Posts: 42; Member since: Sep 19, 2014

i wonder what will happen to apple if samsung gets pissed off and stop supplying parts for apple?

147. Dr.Hye

Posts: 95; Member since: Apr 16, 2014

Then you must still be in 2012.

60. bur60

Posts: 981; Member since: Jul 07, 2014

Why dont they add z3 compact in the list as standard? It gets almost the same scores as the iPhones with its 720p.. stupid PA

113. vincelongman

Posts: 5724; Member since: Feb 10, 2013

Also why use browser benchmarks (Sunspider & Kraken) to compare CPU performance They mainly test Safari Vs Chrome Vs OEM's browser Unless if they are using the same browser They should have used Geekbench (a CPU benchmark) for the comparisons (though ARM v8 has an advantage) ~4200 - Note 4 (Exynos 8433 ARM v8) ~3200 - NVIDIA SHIELD Tablet (K1 ARM v7) ~3200 - Samsung Galaxy Alpha (Exynos 8430 ARM v7) ~3200 - Samsung Galaxy S5 LTE-A (Snapdragon 805 ARM v7) ~2900 - Moto X (2014) (Snapdragon 801 ARM v7)

138. vgroc

Posts: 1; Member since: Sep 22, 2014

Absolutely correct. They should have used Geekbench (CPU) and Antutu (overall benchmark) for CPU comparisons. Whoever made this article tried to make A8 look better. All in all, the new iPhones have a better GPU but Android flagships with SD 801 and newer SoC have a better CPU. So choose what you prefer, personally I don't play games on my phone so I prefer a faster CPU.

155. SteveS

Posts: 51; Member since: Oct 15, 2013

@vincelongman Why stop there... 4477 - iPad Air 2 (Apple A8X)

61. UglyFrank

Posts: 2194; Member since: Jan 23, 2014

It is official S805 is on the same level as the G6450

71. Salazzi

Posts: 537; Member since: Feb 17, 2014

3x the resolution? You don't know what you're talking about. That would mean Samsung phones have 4,000x2,250 if 3x iPhone 6, and 5760x3240p. None of which are reality. As a matter of fact, the S5 has the same resolution as the 6+. The Note 4, which has yet to be released, has less than 2x the resolution of the 6. 1334x750 vs 2560x1440.. double would be 2668x1500. Compared to the 6+, the Note 4 has only 25% more pixels, at 2560x1440 vs 1920x1080. Apple beat the S5 (similar resolution) in all the tests done, both CPU and GPU. To think at 2560x1440, let alone *3* times the resolution, Samsung would be keeping up, when at the same resolution it's behind, is pure ignorance. Let's not even bring up the fact that a device with 2GB ram and Quad core (2.5ghz per core) processor, got it's behind whooped by a Dual core (1.39ghz per core) 1GB ram device.

77. leotrim

Posts: 27; Member since: Oct 01, 2014

2560x1440 it mean 3.686.400 pixel 1920x1080 have just 2.073.600 pixel if u can see note have more around 1.500.000 pixel

85. Salazzi

Posts: 537; Member since: Feb 17, 2014

read again. What was stated was "3x bigger resolution", not "3x more pixels", and my response was targeted toward this comment. Nevertheless, we shouldn't overlook the fact that the S5 has the same amount of pixels as the 6+, and as can be seen, was demolished by the iPhone in comparisons.

79. RebelwithoutaClue unregistered

2560x1440 is 25% more pixels than 1920x1080? More like 77% more pixels. Let's not bring up the fact that an Armv8 64bit cpu is faster than an Armv7 32bit cpu. It has better instruction sets, with double the amount of instructions it can perform simultaneous.

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