What to expect from the iPhone 5S, Apple's A7 and beyond

The History of Apple SoCs
To know where we're going, we need to know where we came from. Prior to the A4, Apple sourced Samsung SoCs for the iPhone, iPhone 3G and iPhone 3GS. Let's take a look at Apple's custom SoCs.

A4
A4:

[10]

• Manufacturer - Samsung on 45nm process (as featured in iPhone 4)
• Die Size - 53 mm2 [5]
• Designer - Apple (Intrinsity[3], also featured in Samsung's 'Hummingbird' SoC[4])
• CPU Type - 800MHz Single Core (as in iPhone 4)
• Instruction Set - ARMv7
• Chip Designator - S5L8930X
• L1 Cache - 32/32KB
• L2 Cache - 512KB
• RAM - 512MB LPDDR @ 400 MHz (as in iPhone 4, 64 bit interface, PoP)
• Max Theoretical Memory Bandwidth - 3.2 GB/s [1]
• GPU Type - Dual Core PowerVR SGX 535 @ 200 MHz
• GPU Performance - 1.6 GFlops, 14 MTriangles/s [2]

A5
A5:

[9]

• Manufacturer - Samsung on 45nm process (as featured in iPhone 4S)
• Die Size - 122.2 mm2
• Designer - Apple
• CPU Type - 800MHz Dual Core
• Instruction Set - ARMv7
• Chip Designator - S5L8940X
• L1 Cache - 32/32KB
• L2 Cache - 1MB
• RAM - 512MB LPDDR2 @ 800 MHz (64 bit interface, PoP)
• Max Theoretical Memory Bandwidth - 6.4 GB/s [1]
• GPU Type - Dual Core PowerVR SGX 543 @ 200 MHz
• GPU Performance - 14.4 GFlops, 70 MTriangles/s [2]

A5X:

[8]

• Manufacturer - Samsung on 45nm process (as featured in "The new iPad")
• Die Size - 165 mm2
• Designer - Apple
• CPU Type - 1GHz Dual Core
• Instruction Set - ARMv7
• Chip Designator - S5L8945X
• L1 Cache - 32/32KB
• L2 Cache - 1MB
• RAM - 1GB LPDDR2 @ 800 MHz (128 bit interface, off package)
• Max Theoretical Memory Bandwidth - 12.8 GB/s [1]
• GPU Type - Quad Core PowerVR SGX 543 @ 250 MHz
• GPU Performance - 36 GFlops, 175 MTriangles/s [2]

A6
A6:

[7]

• Manufacturer - Samsung on HKMG 32nm process
• Die Size - 96.71 mm2
• Designer - Apple
• CPU Type - 1.3GHz Dual Core
• Instruction Set - ARMv7s
• Chip Designator - S5L8950X
• L1 Cache - 32/32KB
• L2 Cache - 1MB
• RAM - 1GB LPDDR2 @ 1066 MHz (64 bit interface, PoP)
• Max Theoretical Memory Bandwidth - 8.5 GB/s [1]
• GPU Type - Triple Core PowerVR SGX 543 @ 320 MHz
• GPU Performance - 34.6 GFlops, 168 MTriangles/s [2]

A6X:

[6]

• Manufacturer - Samsung on HKMG 32nm process
• Die Size - 123 mm2
• Designer - Apple
• CPU Type - 1.4GHz Dual Core
• Instruction Set - ARMv7s
• Chip Designator - S5L8955X
• L1 Cache - 32/32KB
• L2 Cache - 1MB
• RAM - 1GB LPDDR2 @ 1066 MHz (128 bit interface, off package)
• Max Theoretical Memory Bandwidth - 17 GB/s [1]
• GPU Type - Quad Core PowerVR SGX 554 @ 280 MHz [13][14]
• GPU Performance - 80.6 GFlops, 196 MTriangles/s [2]

Apple A-series family tree:

[11]

Functional block size allocation on die:

[12]

A7 Prediction
A7

• Manufacturer - Samsung on HKMG 28nm process
• Die Size - 90-120 mm2
• Designer - Apple
• CPU Type - 1.3-1.6GHz Dual Core "Second Generation Swift Core"
• Instruction Set - ARMv7s
• Chip Designator - S5L8960X
• L1 Cache - 32/32KB
• L2 Cache - 1MB
• RAM - 1GB LPDDR3 @ 1333 MHz (64 bit interface, PoP)
• Max Theoretical Memory Bandwidth - 10.6 GB/s
• GPU Type - "Quad Cluster" PowerVR 6430 @ 400 MHz
• GPU Performance - 102.4 GFlops, 233 MTriangles/s

A7X

• Manufacturer - Samsung on HKMG 28nm process
• Die Size - 110-150 mm2
• Designer - Apple
• CPU Type - 1.4-1.7GHz Dual Core "Second Generation Swift Core"
• Instruction Set - ARMv7s
• Chip Designator - S5L8965X
• L1 Cache - 32/32KB
• L2 Cache - 1MB
• RAM - 1GB LPDDR3 @ 1333 MHz (128 bit interface, off package)
• Max Theoretical Memory Bandwidth - 21.5 GB/s
• GPU Type - "Hex Cluster" PowerVR 6630 @ 400-600 MHz
• GPU Performance - 153.6-230.4 GFlops, 350-525 MTriangles/s

A7 annotated (update):


SoC
These predictions are not totally made up. Anand Shimpi from anandtech also thinks we'll see some sort of 2nd generation swift core from Apple, in addition to a "Rogue" series GPU. Brian Klug, also from anandtech, thinks Samsung's 28nm process will be the process of the A7/A7X as well. Similarly, Andrew Cunningham from Ars Technica also suspects we'll see a modified Swift core along with a Rogue family GPU.

CPU
Concerning Swift, there's likely more blood to squeeze from the stone when it comes to CPU architecture. Qualcomm was able to improve their architecture in successive generations of Krait (their custom ARM v7s core), adding things like L2 pre-fetch and better branch prediction. Both of those boil down to more instructions executed at the same clock frequency (IPC, Instructions Per Clock). The reason for comparison between Krait and Swift goes beyond the fact that they are both custom designed. They share similar clock speeds and pipeline depth as well. The shorter pipeline tends to lead to slower clocked designs but also leads to smaller cores as less memory is needed to store data in between successive pipeline stages.

When talking about Apple's CPU efforts, it's important to remember how they got the capability level they are at now. Acquiring Intrinsity, PA Semi, among others, and hiring top CPU architects from AMD shows how serious Apple is about top performing, custom CPU solutions.

Apple also turned heads with their Macroscalar trademark last year, but it is unclear whether any technology related to this has come to market or why Apple felt the need to trademark what would likely be considered a trade secret design process. Moreover, all speculation about the trademark seems to come back to established methods of branch prediction and speculative execution. It will be interesting to see if this topic comes up again at all.

For those interested for a much more technical dive into CPU speculation, I recommend visiting beyond3d forums. Posts such as this one go into great detail about how Apple may widen and strengthen the execution paths, arithmetic performance and branch prediction.

The 64-bit rumor
A week ago, a rumor popped up that Apple's A7 SoC would feature 64 bit CPU cores. The source, Clayton Morris, has a good enough track record the rumor to be credible. However, I believe it to be highly unlikely that Apple's A7 will be 64 bit.

The first reason A7 will not be 64 bit is rather simple: their competition has not announced any designs for that form factor. Whatever technology Apple surprises us with in their SoC designs, there is usually some vendor who has announced a part with similar features. As of yet, there are no announced 64 bit ARM cores (A57, A53) for the smartphone or tablet form factors. Designs have taped out, but they're not launching anytime soon. Nvidia's Tegra 6, "Parker" SoC will be 64-bit but its predecessor "Logan" has even yet to launch. To put it simply, there is a lot of design time that needs to occur between ARM announcing a core (and ISA) and actual implementations reaching the market. Granted, full licensees of ARM cores such as Apple and Qualcomm have access to these cores and instructions sets before their official announcement, and the time to release of SoCs has been decreasing from these announcements as competition stiffens in the mobile space. There is still an issue of time needed to complete a design.

The second reason 64 bit is unlikely is that there is an issue of manpower. Given Swift's full custom design in the A6 and A6x, it is likely that all future Apple CPU designs will also be fully custom. For Apple to launch a fully custom 64 bit A7 this year, it would have to have been developed in parallel with the Swift cores in the A6 and A6X. This is further complicated by the fact that A6X has many unique features over the A6 which require their own custom design. Intel, who also does full custom CPU cores, releases a new CPU architecture every Spring, and has alternating teams which do each successive CPU design. It is not known if Apple has multiple such teams, but it is an indicator of the engineering manpower needed to achieve such a release schedule.

The last reason is that the need for 64 bit is ambiguous. ARM's 64 bit A57 core is rated at 4.1 DMIPS/MHz (Dhrystone Millions of Instructions Per Second/Megahertz) while Qualcomm's best Krait core is rated at 3.4 DMIPS/MHz compared to the stock Cortex A15 at 3.5 DMIPS/MHz (I suspect the Apple A6 has a similar DMIPS/MHz score to Krait given they have a similar number of CPU pipeline stages), so there's no question that a stock implementation would be faster than the A6 given the similarity of Swift and Krait CPU designs. It's important to note that many have suggested that ARM's aim with the 64 bit architecture is beyond mobile and aimed at laptop and even server implementations. Indeed, AMD has announced a 64 bit ARM part intended for servers. There were similar claims about the A15 being intended for bigger devices, with Samsung's Exynos 5 win for the Google Chromebook as a good example. Meanwhile, Qualcomm's Krait core which is based on the same instruction set but features a simpler, smaller core has enjoyed many of the design wins in the mobile device space.

I should note that many of Apple's performance metrics are not publicly known, so it's difficult to determine the performance threshold Apple is booking for the move to 64 bit. This similarly complicates predictions about the transition to quad core. Of course, there is also the lack of references to 64 bit in any of the iOS releases, but given that iOS is built on the same core as OSX which is fully 64 bit, there's no doubt the foundation is there and 32 bit applications would be compatible.

Going to quad core
I have no doubt that Apple's A-series SoCs will eventually go to a quad core design. The problem is that it's difficult to tell when. Apple surely has many internal CPU profiling tools that tell them the core utilization of various bits of iOS. Indeed, references to quad core chips were showing up in even iOS 5. So, Apple likely has test chips that are quad core which they are testing the performance compared to dual core SoCs. It is also likely that Apple has 64 bit test chips for much the same reason, which may be the source of the 64 bit rumor. The move is a complex trade of die space, power consumption and CPU performance. Since none of those tools or results are publicly known, it's difficult to know when the performance will demand the switch. Whenever the switch is, it has to be worth the increased die area and power consumption (the added cores will increase leakage even if they are never used). So, the best answer I can give for a prediction here is maybe.

big.LITTLE
big.LITTLE is a heterogenous computing paradigm where simpler, smaller cores are paired with compatible complex cores so that they can be powered on in low CPU demand scenarios to save power. This is made possible by power gating, which effectively turns off all power to a CPU core when it is not in use. Nvidia actually implemented this concept in their Tegra 3 SoC before big.LITTLE was introduced alongside the Cortex A15 core. Their low power "shadow core" was able to power up in low demand CPU scenarios and use less power than a full CPU core would to accomplish small tasks.

The issue with ARM's big.LITTLE is that it demands that the number of low power Cortex A7 cores match the number of full power A15 cores. This is why Samsung bills their Exynos 5 series as an "octa-core" SoC when in reality no more than 4 CPU cores can be in use at any one time. The fact that Samsung's flagship Galaxy S4 uses a qualcomm SoC rather than their own Exynos SoC in North America is very telling. Adding 4 low power cores to meet the big.LITTLE architectural requirements is simply not practical from a die area point of view and is likely one of the reasons why we've not seen such an implementation from Apple. If they were to do one, it would likely be a custom implementation that features only a single core such as Nvidia's tegra 3. Nvidia implemented the same concept in the Tegra 4 by featuring a single, low power Cortex A15 core. However, we can be sure that Apple will do the thing that optimizes their power usage, since they rarely fall prey to the "spec wars" where they market numbers rather than user experience. Thus, it is possible that we will never see a heterogenous CPU design from Apple.

The most damning thing with regards to this approach is that Qualcomm's similarly designed Krait doesn't employ the scheme. In this PDF whitepaper, Qualcomm details what they call asynchronous Symmetrical Multi-Processor (aSMP) that allows each CPU core to have its voltage and clock frequency scaled independently, even when another core is in use. They claim that this granularity in power usage per core obviates the need for big.LITTLE all together. It is likely that Apple uses a similar scheme for their Swift cores. If they don't already, it is a very safe bet it is on their near-term roadmap.

GPU
All versions of the iPhone have featured a GPU from Imagination Technologies. In fact, Apple owns around a 10% stake in them as well (an interesting side note- ImgTec acquired Caustic Graphics, a company focused on creating dedicated ray tracing hardware that was comprised of former Apple engineers). It seems all but certain that Apple's A7 and A7X will feature ImgTec graphics core as well. All speculation surrounding the GPU assumes that the graphics cores will be from the Series 6 "Rogue" line of cores. MediaTek has announced a line of SoCs that feature Rogue cores and are launching in Q4 2013, so the timing seems feasible for Apple. ImgTec has made some wild claims about their new GPU architecture such as that it is 20 times faster than previous cores and 5 times more efficient. The points of comparison and metrics are unknown, but when you look at the theoretical FLOPs on the new cores, it's easy to see they're a lot faster.

Looking at the above list in the link, I tried to make a prediction that had a moderate to substantial increase in FLOPs and MPOLY/s for both the A7 and A7X. Without knowing the size or typical power usage of any of these cores, it's difficult to guess what Apple may use. It's also important to note that all of these cores are also available in multi-core variants, so future versions of A-series SoCs may have MP2-4 versions of these cores. Each "core" is made up of a variable size of clusters from 1 to 6, hence the G61xx to G66xx names. It is somewhat useful to compare the different sizes to the SGX 535, 543, 544 and 554 from the 5 series, as they are scaled versions of one another in respect to same aspects of the execution paths. The variants with "30" on the end as opposed to "00" have added frame buffer compression logic. This would allow more data to occupy the same amount of memory or to effectively increase the bandwidth by pushing the same amount of data that is now compressed.

It seems highly likely Apple would use these variants, as they often choose larger dies when the performance or efficiency gains justify it. Given that no G6600 exists, I've taken this as a potential clue that the next iPad will use the G6630, as it has the appearance of being tailor-made for Apple. Because of that, I've assumed that the next iphone will use the G6430, as it keeps it within a 2x factor of iPad GPU performance (as is historically customary) and also pegs its performance above that of the iPhone 5. Given that this architecture is more efficient, we'll likely be getting more performance for a given amount of FLOPs, so don't read these numbers and compare directly to the iPhone 5 and iPad 4's GPUs.

It is difficult to know the target frequency Apple is aiming for on their GPUs. There is likely some performance curve that weighs more clusters versus more clock speed for a given performance. ImgTec's reference speed for these cores is 600 MHz, so I've assumed that will be the next iPad's GPU frequency. I've also assumed that the next iPhone will be lower, somewhat closer to 400 MHz. Although, I would not be surprised if the actual numbers were half of my guesses. Still, I expect Apple's GPU claims to say they are somewhere between 2x and 5x faster, depending upon how much they leverage ImgTec's big claim that they can be up to 20 times faster.

Rogue cores will also bring compliance to some of the later graphics standards, such as openGL 4 and openGL ES 3. This means more advanced effects will be available to game and media developers should they choose to use them.

The Orlando GPU Team
Apple's Orlando GPU design center has been getting a lot of attention lately. They have been recruiting a lot of top talent from AMD's Orlando GPU design center. While it may be an obvious indicator Apple wants to build its own GPUs, there may be more going on than that.

Given Apple's stake in ImgTec, it seems likely that they would task this team to develop more custom versions of their graphics IP. This would be similar to the difference in ARM licensees where some vendors just license the vanilla cores whereas others like Apple and Qualcomm become full licensees so that they can design their own cores which still comply to the instruction set architecture set forth by ARM. It would be difficult for Apple to develop its own original graphics architecture given the size of the task and difficulty with licensing existing patents on the market.

I suspect that their ambition lies beyond simple A-series GPU versions, and they possible have their eyes on making a low power, integrated part for their laptop lineup, starting with the macbook air. They may need to scale the size of the Rogue cores beyond what the mobile or tablet space would call for, and so they hired many engineers to accomplish that task.

It's also possible that Apple will undertake some effort on the API and driver side to improve performance from that angle. Whatever their plans, it seems apparent they have something pretty big in the works and I expect it to have more impact than a faster iPhone and iPad.

RAM
The iPhone 5S MacRumors preview helps us here again because 1 GB of RAM has been spotted on the leaked A7 PCB, making this RAM size a safe bet. Apple's strict use of APIs for third party developers and memory management significantly lessens the need for larger RAM sizes as seen in competing Android smartphones.

LPDDR3 is very likely, given that many of Apple's competitors use it now and Apple uses it in their own 2013 Macbook Airs. It offers faster speeds and lower power usage compared to LPDDR2. My guess of 1333 MHz for A7 and A7X is simply that, a guess. Apple used 1066 MHz LPDDR2 in A6 and A6X so I am assuming they will target faster performance with the upgrade in memory type.

I also expect that the RAM will be Package of Package (PoP) as seen in previous iPhone SoCs. This allows them to save board space by stacking the RAM on top of the SoC in one integrated solution. Similarly, I also expect the A7X to have its RAM off package, as its higher TDP and doubled memory interface complicate a PoP solution, just as we've seen with previous iPads.

Looking into the future, it is likely that we will eventually see 3D IC memory solutions from Apple for their SoCs. Rather than having individual solder bumps from the memory chip to the interconnects, 3D IC solutions allow the memory to directly interconnect to the SoC through a silicon substrate by what are called through silicon vias (TSV). This will allow for greatly expanded memory interfaces that are 512 or even 1024 bits wide in comparison to the 64 and 128 bit interfaces currently seen in the iPhone and iPad. Sony uses a predecessor to this technique called System in Package (SiP) that uses fine wires as opposed to solder bumps, allowing them to achieve more interconnects in a given space. This allows the Vita's GPU to have a 512 bit interface to its VRAM. Whatever solution they use, it will allow Apple to greatly improve memory bandwidth, which can bottleneck GPU performance.

Fixed function blocks
The EETimes article ([12],[13]) goes into great detail about comparing the size of the CPU cores in the A6 to the A5 for those interested. It also helps to illustrate that the CPU has taken increasingly larger amounts of the overall die area in Apple's A-series SoCs (also true of the GPU).

The die allocation image above shows that the number of digital blocks on the A-series SoCs has been increasing. Indeed, with acquisitions like Anobit and Authentec, Apple is poised to put more and more custom circuitry on the SoC itself, freeing up space on their board and allowing them to tailor the solutions exactly to their performance and power needs. I expect this number to go up over time.

Apple also surprised many last year when it was found out that Audience's EarSmart noise cancellation technology would not be in the iPhone 5. The fact that they developed and completed the IP to Apple's requirements suggests that Apple potentially competed them against their own internal team. If this was the case, Apple may been able to meet its own requirements with an in-house solution, eliminating the need to license the IP from Audience. This is just another example of Apple's aggressive pursuit of solutions that are integrated, custom and internally created.

There was also an interesting analysis that arose after the AppleTV received a new version of the A5 SoC that trimmed the CPU to a single core and significantly reduced the size of the die. This seems to be thanks to some custom analog circuitry redesign, which suggests Apple is also increasing its design expertise there. Similar reductions in future SoCs would allow Apple to make all of their dies smaller, saving money, or use that area for something else, increasing performance without increasing size comparatively. The AppleTV was a good product to make this change on because it allowed them to test out their new circuitry in a relatively low volume part.

Comments on design fabrication process, TDP, and die size
The predictions that Apple will use Samsung's 28nm process for their A7 and A7X SoCs are commonplace. Samsung seemingly has achieved sufficient volume for the process for use in Apple's iPhones, but there are allegations that they are having yield issues. TSMC, who has had a 28nm process since late 2011, uses a different manufacturing method (gate last versus gate first) that they claim is easier to yield, so this may be behind it. Samsung does have announced products based on its 28nm process, but those have yet to ship. TSMC's different process may be one of the many factors complicating Apple's alleged move to TSMC for future A-series SoCs.

Moving to TSMC will also help improve transistor density on a given process, which means Apple will be able to pack more in a given area. This could be another potential source of complications for their switch to TSMC.

Thermal Design Power (TDP) is the thermal budget designers work in to manage the heat their processors create. Over the years, mobile chip TDPs have been increasing all the way up to 8W. Anandtech talks about this in their excellent x86 vs ARM showdown piece. They get away with this by executing tasks quicker and shutting down or throttling unneeded resources. TDP is one of the reasons that Apple does not put the RAM on the package in its iPad. iPads feature higher CPU frequencies and larger GPUs, generating more heat, which can necessitate moving the RAM off package to allow for a better thermal sink on the package. TDP is important because since we are starting to reach practical limits, there are no more easy gains to be had in speeding up CPUs and GPUs. The days of a 2x improvement each SoC generation are behind us, and that's likely we're hearing rumors that Apple's next SoC is only 31% faster (for comparison, successive Intel cores are only about 10-15% faster each generation).

Finally, we get to die size. One of the biggest complicators in predicting die size for the A7 and A7X is the GPU. Not only do we not know which GPU Apple will use from the Rogue line for A7 and A7X, we also have no published or estimated die sizes for the Rogue cores from ImgTec. Thus, its easiest to assume the CPU and rest of the die will stay relatively the same while the GPU portion goes up or stays the same. The move from 32nm to 28nm will also allow them to get more transistors in a given die size.

If you compare Apple to their competitors in the mobile space, you see just how aggressive they are with their die sizes. Nvidia's Tegra 3 and Tegra 4 SoCs are only about 80 mm^2. Apple's largest, the A5X, was over double that at 165 mm^2. This kind of die size translates directly to more expense on Apple's part, and SoCs are one of the single most expensive components in the phone (along with the display and NAND storage). I have seen speculation that Apple uses special types of logic in their designs that are physically larger but are advantageous otherwise in the speed and power that they use for a given amount of performance. I exchanged PMs with forum member cmaier on this topic, but he unfortunately is no longer an active member here.

Cellular radio
While there had been some speculation that the next iPhone may feature Qualcomm's next generation all-in-one 9625 Gobi chipset (product table PDF here), it seems more likely that it will retain the 9615 radio found in the iPhone 5. This is based on a tweet from AnandTech's Brian Klug that suggests he has some inside knowledge backing this that he is unwilling to share. This fact is no great loss to the iPhone 5S though, because the 9625's main feature over the 9615 is LTE Advanced. While LTE Advanced allows for higher maximum data rates, it has been deployed virtually nowhere and domestic carriers are just now starting to talk about implementing it. When it does come, users will also be able to enjoy carrier aggregation, which allows the radio to source data on two different frequencies and essentially double its bandwidth.

The second thing that Klug's tweet mentions is the inclusion of the WTR1605L, compared to the RTR8600 in the iPhone 5. This would be a significant development because it would allow the iPhone to support China Mobile's TD-SCDMA network. It seems a fairly good bet that if the iPhone 5S does have this transceiver, it will indeed debut on China Mobile's network at some time. It also seems very probable that this is one of the reasons for the iPhone 5C's existence, so that it can support China Mobile's network as well.

An added bonus of switching to WTR1605L is that the package is about half the size of the RTR8600, which will save precious PCB space for other components.

It will be interesting to see if Apple choses to do an all-in-one solution with regards to SKU that the WTR1605L would enable, but that would require multiple power amplifiers on board to accomplish. This uses more power and board space. Apple likely opted to not do this to save on those two metrics at the cost of doing multiple SKUs. For a more detailed analysis of the iPhone 5's radio solutions, read here (although he is incorrect about 9615 not supporting TD-SCDMA, it's the RTR8600 that causes that).

NAND storage
The excellent iPhone 5S rumor roundup from MacRumors sheds light on the rumor of a 128GB iPhone, with leading analysts predicting its coming. The first and most important consideration when talking about this is whether it's even technically possible. The iPhone only uses a single NAND module to save space, whereas the iPad and iPod touch enjoy two (making the 128GB iPad easily possible). Fortunately, such modules are technically possible. Over a year ago, Sandisk announced they are making 128 gigabit NAND memory chips. With the typically 8 chip NAND module arrangement, this would allow for a 128GB NAND module. It also seems likely enough time has elapsed for these chips to be available in the volume Apple needs.

The other concern with such an iPhone is what Apple thinks the market will support. Demand for the 128GB iPad and many users' iTunes library sizes no doubt suggest there would be demand for such an iPhone. Apple has also done a maximum storage bump on every "S" model (3GS introduced 32GB, 4S introduced 64GB). The difficulty would be in price and SKU management. Do they add a 4th storage option like the iPad and increase the price ceiling by another hundred dollars, creating a $499 subsidized iPhone? Or, would it better to drop the low-end of 16GB and maintain the current price points? It's also possible that they could drop the 64GB option and replace it with 128GB, thus making the bottom two iPhones no more expensive to produce. In any event, a 128GB iPhone seems likely, but I am very skeptical about any raise on the price ceiling of the iPhone models.

Display
The display is an interesting category because the blanket assumption has been that it will be unchanged from the iPhone 5. This is supported by the fact that Apple has never changed the screen in successive iPhone incarnations. There's arguably little to improve too when you consider the enhanced color gamut, superior lamination making it thinner and all around great performance. While I do not believe that we will see any changes that enhance the quality of the display, it is likely some technology changes are coming this generation if not in future ones.

For one, IGZO (Indium Gallium Zinc Oxide) displays have been rumored for years now. The benefits of IGZO are increased carrier mobility (electrons can move easier) and lower off current (display steals less power through leakage when off). IGZO also has increased transparency, meaning the backlight can use less power for the same achieved brightness for the user, also saving power. Sharp started production of displays in 2012. Samsung is the only other licensed manufacturer. Given rumors that Apple may be forced to use Samsung as a display provider again, it appears IGZO could be coming sometime soon.

There is a question of volume, however, given that the technology is relatively new. There are two phones on the market that utilize IGZO displays, but neither of them come close to approaching the volume that Apple would require for the iPhone. Sharp also uses them in some laptops and TVs, showing that an iPad option is viable too.

Apple no doubt also has quality standards in both produceability and performance that must be met too. Given the available power savings by using IGZO, it seems only a question of when and not if for the technology. (I was previously not aware that Apple already used LTPS for their LCDs for their iPhone displays, which is superior to IGZO in many respects in which it excels, at the cost of being more expensive. Thanks, fertilized-egg)

Another potential power-saving move would be to use a strategy similar to LG's G2 smartphone, which has a local "GRAM" for the display buffer. If the screen has no change in the image it needs to display, it simply refreshes from the local RAM rather than forcing the display controller to generate the same image again for the display to use. They claim up to a 26% savings in power, although this would certainly depend on usage scenario. When you look at the power usage by component in the typical smartphone, the display is almost always leading the pack over the rest of the components, making it is easy to see why this idea has merit.

Battery
Last year I created a thread that highlighted the battery chemistry change in the iPhone 5. The new chemistry allows for more efficient power delivery and potentially more cycles of the battery for its lifetime. The iPhone 5 battery life is 1440 mAh. The leaked battery (as seen in the rumor roundup) suggests that the new battery will be 1564 mAh. This 8.5% boost in battery longevity will likely lead to increased battery life or the same battery life with a more demanding A7 SoC. This is also the biggest jump in battery capacity since the iphone 4 was introduced at 1420 mAh, improving over the 1219 mAh of the 3GS (battery capacity did drop from 1400 mAh to 1150 mAh going from the iPhone to iPhone 3G).

Fingerprint scanning home button
This one is rather simple. Leaked parts, iOS references and analysts all point to a fingerprint scanning home button. Apple's authentec acquisition made this possible, and I expect there will be some special circuitry housed on the SoC to perform the necessary calculations for quick validation and unlocking functions.

Camera
This one is also simple, and I do not have anything to add on to the rumors that are well sourced in MacRumor's guide. A dual LED flash will enhance low-light performance and increase dynamic range. A wider f/2.0 aperture will let more light in, meaning the shutter has to be open for less time, reducing the chance of a blurry shot. It seems up in the air whether it will be an 8 or 12 megapixel camera. It is a safe bet that Apple would only increase the MP count if they did not have to sacrifice on pixel sensor size, since this would directly affect image quality. Apple has always stressed the quality of images over touting impressive spec numbers when it comes to camera performance.

jkauff said:

Why nothing about the audio chip? The Cirrus Logic chip supporting 24/192 audio has come down in price since the iPhone 5 was introduced. Will the 5S have it? Will the iTunes Store begin to offer hi-res music downloads soon, like HDTracks? Music freaks need to know!

Click to expand...

Very good question. First of all, fortunately or unfortunately depending on how you look at it, I don't think component cost is the reason the things keeping them from using that chip that promises higher fidelity. They've traditionally sourced premium, high price parts when the fit, finish or function of the phone demanded it. They likely feel no impetus to push towards higher fidelity audio due to them having cornered the market and people who demand lossless formats are a vast minority. They probably feel that AAC is "good enough" and might even say most double blind listeners wouldn't be able to tell you the difference. That's when you look beyond the fact that many modern audio masters are over saturated, destroying the benefit of such solutions that would better deliver on high dynamic range.

If you look in the display section, I mention LG's G2 smartphone. In addition to their neat GRAM concept, they're also touting that their phone is capable of full 24 bit 192 kHz FLAC/WAC playback. They even rewrote some bits of android to make it fully compatible. HTC has made similar efforts to emphasize audio, although more so from a branding standpoint. Still, the audio out of the HTC One is quite loud, clear and impressive compared to the iPhone's offerings. However, these never have to been major sales drivers because like I said, those demanding lossless audio are a very small group.

So, the reason I didn't talk about it is mostly because no one else is. Apple has never seemed to make a deal about their audio performance, or no pundits seem to care either really.

I certainly understand your frustration though. The number of MFi DACs is a very short and expensive list. I'm looking forward to potentially cheaper options in the future. I'm not holding my breath for any move by Apple, unless it just so happens that the high fidelity chip is chosen for some other reason or it becomes the norm and they have no choice but to use it. At least ALAC exists for those who rip CDs.

jkauff said:

Thanks for the thorough reply. I don't agree about the pundits, though, a quick Google search for "smartphone" and "audiophile" will turn up a number of comparison tests. The no-moving-parts, built-in clock, and no jitter qualities of smartphones is making them a serious alternative to the add-on DAC route.

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When I say pundits, I mean the more recognizable figures in the gadget world. That's not to downplay the professionals who care about things like DAC quality, it's just to point out that the community for those authors is much smaller.

I know the HDTracks clientele is very small, but the profit margins on those downloads is very high. Apple has been requiring the music companies to deliver minimum 24/96 masters for over a year now, and rumor has it that the iTunes Store converted internally to the HD-AAC codec, which supports lossless, hi-res, lossy, and streaming from a single master file.

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I don't think profit margins alone are a good enough motivator when you're as big a player as Apple is. I think the fact that Apple has been requiring higher quality masters is the biggest supporter of your hope for a better quality DAC in the future. Especially if that rumor is true.

It's not like Apple to leave even small amounts of money on the table when it costs them nothing. Then there are the complaints that Apple is no longer an innovator, and the fact that Steve Jobs was an audiophile himself. Seems like an easy win to me.

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I think there are plenty of cases to be made where Apple has opted for a smaller, more focused product line at the expense of potentially reaching more users. The lack of a larger screen iPhone being a prime example.

You have to remember that while the audiophile community may be tens of thousands of passionate, loyal users, the iPhone community is tens of missions of people with many of the same qualities.

It is really complicated from a prediction standpoint when you consider all of the performance measurements and metrics audiophiles use to objectively determine quality. If you go by that, each successive iDevice seems arbitrary, with it sometimes being better than before, and sometimes being worse. Thus, that's why I think in some cases, there's simply a "good enough" bar where size, power consumption and other parameters take precedence over bleeding edge audio performance.

Perhaps Apple will surprise us by touting their excellent audio performance like they talk about camera performance. I think that's one of the excitement factors- you never known what Apple is going to convince people they can't live without next.

In regards to the China media event on Sept 11, I would say that all but confirms the use of the WTR1605L transceiver from Qualcomm in the iPhone. I still expect different SKUs in the US for different carriers to avoid more parts such as power amplifiers.

Updating with post from other thread. 9615 seems pretty sure if the leaked PCB is the 5S, which it seems to be because it has a brand new SoC.

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Brian Klug, from Anandtech, has been able to tell the pad patterns from the leaked PCB. It matches the 9615, which is apparently not pin compatible with the 9625.

https://twitter.com/nerdtalker/status/375757081409617920

It doesn’t really change my mind, the leaked boards I’ve seen have the pad numbers for 9615

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Seems like the only out is if that was a pre-production version that was changed later to have the 9625. I don't think we've ever seen parts change from a leak to final PCB though.

Skika said:

Wait, the A4 was dual core and had 256 mb of RAM? Isnt this incorrect

The iPad version as far as i know had 256, the iPhone had 512, but none was dual core?

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Good catch. Copy paste error on the core count and I simply made a mistake on the RAM quoting the iPad. I added qualifiers for the iPhone 4 to avoid confusion.

Chocolatemilty said:

Excellent post, chrmjenkins, thank you!

One thing I did want in the iPhone 5S that I've forgotten about over the months is the inclusion of the Gobi chip for LTE-A. I know carriers in the US aren't very close to deploying it, but Deutsche Telekom just announced their LTE-A network, and T-Mobile and AT&T are nearing announcements in 2014. Sounds like a great way to not let sales sag into the summer months of 2014, especially as rumors and speculation ramp up for the "bigger-screened iPhone 6" if, in fact, the 5S is capable of LTE-A with a carrier update.

Thoughts?

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See post #18. The leaked PCB doesn't have the proper pinout for the 9625 (supports LTE-A). Its pinout matches the 9615 used currently. So it's possible that that PCB is the 5C (with the 5C containing the latest SoC; not expected as a lower cost iphone), or it's possible it's some sort of prototype board with non-final parts. However, there's never been a board leak that ended up having different components than the final PCB. All things considered, it looks like we are stuck with 9615 for another generation if that leaked PCB is legitimate.

It's important to remember that carriers are still deploying more bandwidth in ways that don't depend on carrier aggregation (LTE-A) at the user's end to get that increased bandwidth. There are quite a few good technical posts in the Deustche Telekom thread that discuss this, such as milan03's posts.