The iPhone 5 Review
by Anand Lal Shimpi, Brian Klug & Vivek Gowri on October 16, 2012 11:33 AM EST- Posted in
- Smartphones
- Apple
- Mobile
- iPhone 5
The A6 SoC
Section by Anand Shimpi
All great tech companies have their showing up to the fight moment. I borrow this phrasing from former ATI/AMDer, current Qualcomm-er Eric Demers. While at ATI/AMD, Eric came to the conclusion that the best way to lose market share was by simply not showing up to the fight. Customers tend to spend their money at key points throughout the year (holidays, back to school, etc...). If you don't have something shiny and new when those upticks in spending happen, you're not going to win. Eric called it showing up to the fight. By showing up to the fight every year, you at least had a chance of selling whatever it is that you're trying to hock.
Intel came to a similar realization after the Pentium 4, which eventually resulted in its famous tick-tock cadence. Every year you get evolutionary improvements, either in power or performance (sometimes in both). Over the course of several years, especially if your competition isn't as aggressive, you end up with a series of products that look downright revolutionary.
Apple learned from the best and quickly adopted a similar approach after it released the iPhone in 2007. With the exception of last year's 4S launch, like clockwork, Apple brought out a new iPhone every year at around the same time. The summer launch cycle was pushed back to fall last year but, since then Apple continued its roughly 12 month cadence for the iPhone.
The smartphone SoC space is still operating on this hyper Moore's Law curve which allows for significant innovation on a yearly cadence rather than a big update every 18 - 24 months. Even Intel recognized this fact as it will shift Atom to a yearly update cadence starting towards the end of next year.
The fast pace of changes on the smartphone side combined with the similarly aggressive release schedules from its competitors explain the difference in Apple's approach to iPhone/iPad vs. new Mac releases. The former are launched with much more pomp and circumstance, and are on a 2-year chassis redesign cadence. There's also the fact that devices running iOS make up the largest portion of Apple's yearly revenue. At some point I would expect the innovation/release cadence to slow down, but definitely not for the next few years.
The first few iPhones largely leveraged Samsung designed and manufactured silicon. Back then I heard Samsung was paying close attention to Apple's requirements and fed that experience into its own SoC and smartphone design.
With a couple of successful iPhone generations under its belt, Apple set its sights much higher. Steve Jobs hired some of the brightest minds in CPU and GPU design and kept them close by. They would influence silicon supplier roadmaps as well as help ensure Apple was on the forefront of performance. Remember that CPU and GPU makers don't just set their own roadmaps, they ask their biggest customers and software vendors what they would like to see. As Apple grew in size, Apple's demands carried more weight.
Unlike the desktop/notebook CPU space, there was no truly aggressive SoC provider. The why is easy to understand. Mobile SoCs sell for $14 - $30, while the desktop and notebook CPUs that Intel invests so heavily in sell for around 10x that, despite being 1 - 4x the physical die size of their cheaper mobile counterparts. In short, most SoC providers felt that no one would be willing to pay for a big, high performance chip, so no one made them. Ultimately this led to a lot of embarassment, with companies like NVIDIA being known for their graphics prowess losing when it came to SoC GPU performance.
Realizing the lack of an Intel-like player in the mobile SoC space, Apple took it upon itself to build the silicon it needed to power the iPhone and iPad. By controlling its own SoC destiny it could achieve a level of vertical integration that no OEM has enjoyed in recent history. Apple would be able to define the experience it wanted, then work with the device, OS, application and SoC teams to deliver that experience. It's a very tempting thing to strive for, the risks are plentiful but the upside is tremendous.
The A4 SoC was Apple's first branded solution, although internally it still leveraged licensed IP blocks from ARM (Cortex A8) and Imagination Technologies (PowerVR SGX 535). Its replacement, the A5, moved to a dual-core Cortex A9 setup with a much beefier GPU from Imagination (PowerVR SGX 543MP2). For the 3rd generation iPad, Apple doubled up GPU core count and built the largest ARM based mobile SoC we've seen deployed.
When I first looked at the A4, I wrote the following:
Apple is not a microprocessor company, nor does Apple want to toss its hat in with the likes of Intel, NVIDIA, Qualcomm and TI as an SoC maker. History has shown us that the only way to be a successful microprocessor company is to be able to subsidize the high cost of designing a powerful architecture over an extremely large install base. That's why x86 survived, and it's why the ARM business model works.
Designing high performance SoCs just for use in the iPad and iPhone just doesn't make sense. In the short term, perhaps, but in the long run it would mean that Apple would have to grow the microprocessor side of its business considerably. That means tons of engineers, more resources that aren't product focused, and honestly re-inventing the wheel a lot.
The fact that the A4 appears to be little more than a 45nm, 1GHz Cortex A8 paired with a PowerVR SGX GPU tells me that Apple isn't off its rocker. I don't exactly know what Apple is doing with all of these CPU and GPU engineers in house, but licensing tech from the companies who have experience in building the architectures is still on the menu.
While I still believe that, long term, Apple will either have to commit to being a full blown chip company or buy processors from whoever ends up dominating the mobile SoC industry it's clear that for the foreseeable future Apple will be a device company that also makes mobile SoCs. Given the state of the mobile SoC space at this point, I can't blame Apple for wanting to build its own chips.
| Apple SoC Evolution | |||||||
| Apple A4 | Apple A5 | Apple A5r2 | Apple A5X | Apple A6 | |||
| Intro Date | 2010 | 2011 | 2012 | 2012 | 2012 | ||
| Intro Product | iPad | iPad 2 | iPad 2 | iPad 3 | iPhone 5 | ||
| Product Targets | iPad/iPhone 4 | iPad 2/iPhone 4S | iPad 2/iPhone 4S | iPad 3 | ? | ||
| CPU | ARM Cortex A8 | 2 x ARM Cortex A9 | 2 x ARM Cortex A9 | 2 x ARM Cortex A9 | 2 x Apple Swift | ||
| CPU Frequency | 1GHz/800MHz (iPad/iPhone) | 1GHz/800MHz (iPad/iPhone) | 1GHz/800MHz (iPad/iPhone) | 1GHz | 1.3GHz | ||
| GPU | PowerVR SGX 535 | PowerVR SGX 543MP2 | PowerVR SGX 543MP2 | PowerVR SGX 543MP4 | PowerVR SGX 543MP3 | ||
| Memory Interface | 32-bit LPDDR2 | 2 x 32-bit LPDDR2 | 2 x 32-bit LPDDR2 | 4 x 32-bit LPDDR2 | 2 x 32-bit LPDDR2 | ||
| Manufacturing Process | Samsung 45nm LP | Samsung 45nm LP | Samsung 32nm LP HK+MG | Samsung 45nm LP | Samsung 32nm LP HK+MG | ||
Apple's A6 is the next step in the company's evolution. Although it continues to license graphics IP from Imagination Technologies (PowerVR SGX 543MP3) and it licenses the ARMv7 instruction set from ARM, it is the first SoC to feature Apple designed CPU cores. The A6 is also the second Apple SoC to be built using Samsung's 32nm LP High-K + Metal Gate transistors. Thanks to UBM Tech Insights and Chipworks we have some great die shots of A6 as well as an accurate die size.
I've updated our die size comparison to put the A6 in perspective:
The new SoC is smaller than the A5 used in the iPhone 4S, but it's built on a newer process which will have some added costs associated with it (at least initially). Over time I would expect A6 pricing to drop below that of the A5, although initially there may not be much (if any at all) cost savings. Note that Apple's 32nm A5r2 is very close in size to the A6, which made it a great test part for Samsung's 32nm process. Apple likely caught the bulk of its process issues on A5r2, making an aggressive ramp for A6 on 32nm much easier than it would have been previously. It's clear that the Apple SoC team benefitted from the practical experience of its members.
Putting the A6 in perspective, we have the usual table we throw in our CPU reviews:
| CPU Specification Comparison | ||||||||
| CPU | Manufacturing Process | Cores | Transistor Count | Die Size | ||||
| Apple A6 | 32nm | 2 | ? | 97mm2 | ||||
| Apple A5X | 45nm | 2 | ? | 163mm2 | ||||
| Apple A5r2 | 32nm | 2 | ? | 71mm2 | ||||
| Apple A5 | 45nm | 2 | ? | 122mm2 | ||||
| Intel Ivy Bridge HE-4 (GT2) | 22nm | 4 | 1.4B | 160mm2 | ||||
| Intel Ivy Bridge HM-4 (GT1) | 22nm | 4 | ? | 133mm2 | ||||
| Intel Ivy Bridge H-2 (GT2) | 22nm | 2 | ? | 118mm2 | ||||
| Intel Ivy Bridge M-2 (GT1) | 22nm | 2 | ? | 94mm2 | ||||
| Intel Sandy Bridge 4C | 32nm | 4 | 995M | 216mm2 | ||||
| Intel Sandy Bridge 2C (GT1) | 32nm | 2 | 504M | 131mm2 | ||||
| Intel Sandy Bridge 2C (GT2) | 32nm | 2 | 624M | 149mm2 | ||||
| NVIDIA Tegra 3 | 40nm | 4+1 | ? | ~80mm2 | ||||
| NVIDIA Tegra 2 | 40nm | 2 | ? | 49mm2 | ||||
Although the A6 is significantly smaller than the mammoth A5X, it's still quite large by mobile SoC standards. At 97mm2 Apple's A6 is slightly larger than a dual-core Ivy Bridge with GT1 graphics. Granted that's not a very impressive part, but it's still a modern chip that Intel sells for over $100. I'm still not sure what the die size sweet spot is for a smartphone/tablet SoC, perhaps something around 120mm2? I just can't see the 200mm2 chips we love on the desktop being the right fit for ultra mobile.
A6 die photo courtesy UBM Tech Insights
Looking at the A6 die we clearly see the two CPU cores, three GPU cores and 2 x 32-bit LPDDR2 memory interfaces. The Chipworks photo shows the GPU cores a bit better:
Apple A6 die photo courtesy Chipworks
Chipworks was first to point out that Apple's custom CPU cores appeared to be largely laid out by hand vs. using automated tools. Not using automated layout for all parts of a CPU isn't unusual (Intel does it all the time), but it is unusual to see in an ARM based mobile SoC. Shortly after the iPhone 5's launch we confirmed that the A6 SoC featured Apple's first internally designed ARM CPU cores. As a recap there are two types of ARM licensees: architecture and processor. A processor license gives you the right to take an ARM designed CPU core and integrate it into your SoC. Apple licensed ARM's Cortex A9 design in the A5/A5X SoCs for example. An architecture license gives you the right to design your own core that implements an ARM instruction set. Marvell and Qualcomm are both examples of ARM architecture licensees.
For years it's been rumored that Apple has held an ARM architecture license. With the A6 we now have conclusive proof. The question is, what does Apple's first custom ARM CPU core look like? Based on Apple's performance claims we know it's more than a Cortex A9. But to find out what the architecture looks like at a high level we had to do a lot of digging.
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name99 - Wednesday, October 17, 2012 - link
If you want to read non-technical reviews, there are a million other sites you can go to, from NYT and WSJ to Engadget and TheVerge.The WHOLE POINT of people reading Anand's reviews is to get tech details we don't get elsewhere.
Perhaps as a followup you might want to suggest that John Siracusa in future limit his OSX reviews to a single letter-sized page?
rarson - Wednesday, October 17, 2012 - link
No, it's not the "WHOLE POINT," the whole point is that reviews are reviews and tech articles are tech articles.GotThumbs - Tuesday, October 16, 2012 - link
"Those longing for an HTC One X or Galaxy S 3 sized device running iOS are out of luck. "I find it hard to believe there is even one person that is in this group. Apple's walled garden is mostly OS and portal based (Itunes).
Especially with Apples maps being sub-standard.
Please stick to facts.
A5 - Tuesday, October 16, 2012 - link
If you don't want any editorial judgement or statements, there are plenty of places where you can just read a spec sheet and benchmark results.Omophorus - Tuesday, October 16, 2012 - link
I think the opposite is more likely... or at least I fall into that category.Mobile computing device aside, Android 4.0+ is shockingly much nicer to use (and this coming from a long time iPhone user) than iOS 5 or iOS6.
If I could get the iPhone 5 handset, maybe with slightly better anodization, running Android 4.0+ I'd be in hog heaven.
After playing with an iPhone 5, I really dig the hardware, but found the software woefully lacking.
crankerchick - Tuesday, October 16, 2012 - link
I think you and the original commenter missed what the statement was saying. It said, "HTC One X or Galaxy S3 'sized' device..."Specifically, a larger screen iPhone, is where I think they were going with the statement, especially given the context of the paragraph where the statement was made.
That said, I'm very much in the same camp as you. My number one device would be an iPhone-size and iPhone-build device running Android (but with a few tweaks since we are talking the ideal device). In fact, that is part of the reason I have an iPhone now and my Galaxy Nexus is sitting in a drawer by the bed--it's just too big and battery life is awful. I want a 4-4.2" 720p screen that doesn't have last year's hardware inside. The One S comes closest, but it's not on VZW to my knowledge, and it's still not "the best" hardware available, which you need with Android, especially on a manufacturer's skinned device.
perpetualdark - Monday, October 22, 2012 - link
What about the Incredible 4g? I think this phone was overlooked because of it's proximity to the S3 release and the fact that the market is generally trending toward a nearly 5" display..I like this phone because it has the current generation of technology, is pretty darn thin, has a replaceable battery, has the 4" display (ie I am not holding a small tablet to my ear or carrying it in my pocket), and is, more importantly, android.
Yes, the SLCD display may not be quite what the apple display is on paper, but to be perfectly honest, I have never noticed the differences.. Perhaps in a test environment, or to someone who calibrates displays all day, the Apple display would be better, I just don't see it.
The s4 processor is not only fast, but plenty efficient, and the battery lasts easily 2 full days of heavy use. I can use it to read a kindle book for 6-8 hours over 2 days, talk a few hours, surf the web a few dozen times, text a few hundred texts, and even play games for an hour or two before I run out of battery. I have yet to go below 40% in one 24 hour period of time with the exception of using it with GPS and maps up.. the gps on 100% burns up the battery fast.
gig of ram, 8 gigs on board storage, 32 more gigs with the sd card, etc, plenty of storage. 8 megapixal camera on back and a vga camera on front.
ICS, LTE, Beats Audio, pretty much all the latest in tech..
No, it can't quite compete with the S3, but it is pretty close to a One X in a 4" package and the closest thing to a One X you can get from Verizon, and honestly the phone that SHOULD be compared to the iphone5, given it is the only one with the current generation of hardware that is the same size. Sure, the iphone5 has an edge on the inc 4g in terms of tech specs, but when you add cost to the mix, the playing field is more level there as well, and to be honest, in real world applications the differences are going to amount to very small percentages.
What people really want is a phone that fits their needs. Usually the most important things are screen size, OS preference, cost, and battery life. Performance is ONLY an issue when there is a problem with it.. Like when the iphone 4 dropped calls and couldn't do internet when you touched it.. The difference from the S4 to the A6 in real world application is a second or two in loading an app.. if even that.. most of my apps open instantly and with chrome and a good 4G connection I am betting that side by side loading web pages would be nearly identical. Specs are cool when comparing e-peen size but otherwise don't mean much in application.
Not everyone is interested in big screens for a phone. Not everyone is interested in having a flexible OS. Not everyone is interested in the latest tech. Not everyone wants to spend a fortune on a phone that is, in practice, marginally better than what they have already. Not everyone is interested in bleeding edge technology. Sometimes you are looking for the phone that best suits YOUR needs. For me, that is an android platform, small form factor to fit in my front pocket comfortably as well as in my hand. A processor that was fast but power conservative. A battery that lasted a full day with reserve to spare, and could be used for 2 or 3 days if conserved well, AND could be swapped with a fully charged battery when travelling. I also like a phone that I can drop and scratch and not notice the dings and scratches.. since I put it in my pocket, I don't want to add a bulky case to keep it safe.. (I have dropped this phone dozens of times and 24" away you would never know it). I like to only pay $6.99 for insurance and be able to replace it if lost or stolen or broken for less than $100 ($12 per month for apple with $170 replacement deductible). And I like that I can use ANY micro-usb charger or cable to charge or connect to a computer. I don't have to buy any special adapters to make it work with my existing devices.
Quite frankly, I think the difference between an android fan and an apple fan is that an android fan will not settle for the one device available to suit his needs, he will shop around to find the RIGHT one. If that happens to be an iphone, that is what he will get. But with dozens of models to choose from that are every bit as good if not better in every way that really matters, the chances of going with an iphone are pretty slim. An apple fan will settle for what is available and try to convince everyone around him that this one device will fit everyone's needs perfectly without exception.
crankerchick - Tuesday, October 16, 2012 - link
I don't follow all the technicals like that, I'm more of an end user when it comes to mobile technology, but I think the trend towards the larger screens is more the MFRs pushing that a selling point (moar moar moar) to cover the fact that they can't fit the latest and greatest and cutting edge (NFC, quad core, LTE, etc) in the chassies of a 4" screen phone.Just my hunch. Wouldn't mind being schooled on this by someone in the know.
KPOM - Tuesday, October 16, 2012 - link
I'd agree with that assessment. Apple was one of the last to move to 3G and one of the last to move to LTE because of battery life. The other manufacturers got around it by building thicker phones in the 3G era, and then with the LTE era started putting in bigger screens, which gave them room for bigger batteries (though the larger displays also required more power). It turned out enough people liked the bigger screens.Now that the power consumption levels are down, it will be interesting to see if others shrink their screens back down to Apple levels. The Galaxy SIII Mini is a half-hearted attempt, as it lacks LTE and has mediocre specs. But maybe someone else will take the bait.
rarson - Thursday, October 18, 2012 - link
I feel like the iPhone 5 screen is actually too small (and I've heard complaints that the phone is too light, which I sort of agree with as well), but I think the Galaxy S3 is too big. I'm still using a Verizon Fascinate. It's got a bigger screen than the 5, but it's a bit smaller than the S2 and S3, perfect size. Thin but not too thin, and light but not too light. In fact, all I really want is a phone exactly like it, but with more power, better battery life, and maybe a slightly better screen (can't complain too much about the screen I already have).When I picked up the Fascinate, I knew it was the phone I wanted (helps that the price was only $50). When the S2 came out, I was excited to see it but disappointed by how much bigger the phone had gotten. I don't want a phone that I have to contort to get into my pocket. Apple's iPhone 5 is great in that respect, but after using this Fascinate for so long, its small size feels a bit cramped.
I'd love to have the hardware of the Apple phone, but proprietary connectors and iOS are absolutely a no-go for me. I really don't care for iOS at all, because Android is so much easier to use.