Fixed function blocks

Comments on design fabrication process, TDP, and die size

Cellular radio

WIFI

NFC

Flash storage

Display

Audio

Battery

Camera

Last year, Apple introduced their "M7" motion coprocessor, which turned out to be a part manufactured by NXP, who can also tout design wins for the display interface and this year's NFC chip. The pad pinout for this processor is conspicuously absent from the logic board of the iPhone 6. Moreover, an inspection of NXP's product offerings doesn't offer a clear successor to this part either. It seems highly unlikely that Apple would do away with this functionality, so the easiest conclusion to make is that the part has changed pinouts or been combined with other functionality into a new part and new pinout. Another option is that Apple licensed the IP such that they could include the processor on the die or in the package of the A8. With Apple's push into health related functions in iOS 8, it seems reasonable that they would step up their efforts in this area, including potentially moving this functionality to a location where it could have a secure enclave of data storage similar to how they store fingerprint data.Including additional circuitry such as this is not free, however, as it can get complicated to create additional clock and power domains on what is already a complicated application processor. This does seem a fair conclusion when the A8's reduced pinout, shown in the PCB analysis section, is taken into account. With fewer pins to interface to the PCB, some of the immediate conclusions would be a reduction in complexity or functionality, a consolidation of functions and hubs onto the chip, or a simplification of interfaces to other chips. Given that the A8 should be a processor with improved capabilities, the first possibility does not seem likely.There have been some interesting articles in the past years on this topic, so I've left the rest of this section for the content I presented last year, unedited.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.It is no secret that Apple has been rumored to be moving to TSMC for production of its A-series SoCs for years. This has also often been accompanied by talk of how Apple seeks to break its dependence on Samsung for key components in its iDevices. This year, it looks as if the stars have finally aligned with TSMC demonstrating a process lead on 20nm technology and apparently having sufficient volume to fulfill the demand in the tens of millions for Apple's devices. Reportedly, Samsung dropped out of A8 production over issues with yield. Indeed, there were reports in March that TSMC had begun production of Apple's A8 processor, followed by rumors that deliveries began in July . As mentioned earlier, should Apple move to the 20nm process with TSMC, it will be a full node shrink from the 28nm node they are currently on with the A7 processor. This is in contrast to the transition from A5 to A6, which was only a half-node transition. With a full node transition, you can usually expect the logic density to go up such that the same functionality takes 50 to 70 percent of the original area. This fact is one of the reasons the apparent shrink of the package and pinout size shouldn't be immediately alarming to those concerned about performance. In fact, Apple has previously been very aggressive with their design sizes. For example, A5X was 165 mm^2, whereas Nvidia's Tegra 4 was only 80 mm^2. That high point has come down in recent years, with the designs over the past few years ranging from around 100 to 120 mm^2. This means that you can get fewer chips per wafer and that if there are any defect rates that associated with area as a factor, yield will suffer as a result. Apple's willingness to bear these risks should show that a potential size reduction on the A8 is not one rooted in conservatism.Moving forward, TSMC looks as though it may have sufficient production capacity on its 16nm FinFET process this time next year. Samsung, along with Global Foundries through their licensing partnership , may also have 14nm FinFET volume capacity next year. There have been conflicting reports of which supplier is slated to supply processors next year, with Global Foundries' facility in New York being named specifically at one time. There have even been rumors that TSMC and Samsung would share production. Ideally, Apple would only choose one of these processes as they have to design and validate to each process, something that would be cost and time prohibitive given that they are now doing full custom designs. Utilizing both processes would also force a lowest common denominator of performance characteristics, unless they segregated processes by device line. The performance delta between the processes is likely to be less than the delta between 20nm and either process, making it a justifiable step forward to go with either supplier.There has also been talk about Intel as a fab partner for their A-series chips. Intel has opened their fabs up to outsiders slowly in recent years, with it perhaps culminating in the revelation that they would produce ARM 64 bit designs. There is still a healthy amount of skepticism surrounding Intel's willingness to produce designs that directly compete with their own markets, or more importantly, markets they desire higher marketshare for, such as mobile products. Intel has generally kept a one process lead over the rest of the market, with their use of FinFETs at 22nm being the best recent example. The fact that use of their technology could create another leap forward in performance means it is a situation worth keeping an eye on.Looking further down the road, the situation becomes even more challenging. Most process roadmaps end around the 3nm to 5nm range. Additionally, after over forty years of improving cost per transistor in electronic devices, that curve is trending back upward. Small feature sizes have forced double patterning on chip designers, significantly raising mask costs. Quantum tunneling has forced foundries to use high-k gate materials. While EUV and 450mm have promises of bring costs back under control, they continue to be pushed back with no definite timeline . FinFETs are only the start of topology changes to make the smaller nodes viable and effectively fight quantum effects and device leakage. From III-V materials, to silicon nanowires, quantum FETs, carbon nanotubes, FD-SOI, FinFET SOI, optical transistors and many more, there are a plethora of technologies that promise to increase performance, overcome limitations and push us into single digit nanometer device feature sizes. While difficulties lie ahead, it is an extremely interesting time to follow the electronics industry.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. Last year, I suggested the days of 2x improvement are over because of TDP limits, only to have Apple prove that wrong by making a much wider design that is 64 bit. But it did come at a cost. The A7 draws over twice the current that A6 does during fixed-point operations, and still nearly double during floating-point operations.Last year, we had rumors of the iPhone 5S possibly including Qualcomm's 9625 modem capable of carrier aggregation. Anandtech's Brian Klug managed to squash that rumor by confirming the pinout for the WTR1605L on the leaked logic board. The most legitimate argument against that rumor was that no carriers had yet deployed carrier aggregation to take advantage of those advanced features. That is changing now, with each of the four major cellular carriers in the process of deploying CA across the nation. Verizon calls it XLTE , T-Mobile calls it wideband LTE , Sprint calls it Spark , and AT&T doesn't have a name for it, but promises peg all four having deployed it by this year's end.Last year, Brian Klug from Anandtech did an excellent summary of the state of Qualcomm's modems and transceivers at the time, detailing the capabilities of the 9625 modem and 1605L transceiver. When Qualcomm announced their fourth generation category 6 LTE modem, the 9x35, he detailed the fact that the 1625L transceiver required the WFR1620 to fully support carrier aggregation with the 9625 modem. Unfortunately, there is no good comparison of the feature set of 1605L vs. 1625L beyond carrier aggregation, but Qualcomm has stated that the 1625L can support every band combination on the market. This means that if the iPhone were to feature it, the number of SKUs forced by differing standards around the world would simply depend on the complexity of Apple's amplifier and switch architecture. With the iPhone 5S, five different implementations were necessary to support all of the carriers for which Apple the iPhone available. Chipworks even did a comparison of the RF front-ends between the Asia/Pacific model and the North America one.The 9625 rumor surfaced again last week after leaked logic boards and schematics emerged. I have since confirmed the presence of the WTR1625L transceiver, which necessitates the modem being the 9625 and the presence of the WFR1620 companion chip. More details of that are in the PCB analysis section. So, buyers of the new iPhone can expect higher peak LTE speeds if their carrier supports CA. It will be interesting going forward to see how many models of the iPhone 6 are required to support all of the carriers Apple deploys the iPhone to, particularly with the logic board growing thanks to the new potential 4.7" and 5.5" screen sizes. It seems unlikely that they will be able to deploy a catch-all model and will still require at least two or three versions. A China Telecom ad seemed to suggest that there would be a comprehensive model for all Chinese carrier options. The leaked PCB suggests that there are again at least six different power amplifiers, but at least one of those appears to be a new multi-mode, multi-band module from Skyworks that supports numerous bands itself.The next generation 9635 modem, which is implemented on a 20nm process rather than the 28nm found in the 9625, was mentioned in at least one rumor regarding the iPhone 6. While that has been confirmed false at this point, it does seem a likely option moving forward, though Apple would likely wait to deploy until at least a few North American carriers deployed advanced LTE features that would take advantage of it, if recent trends are any indication. Other recent advancements by Qualcomm include the WTR3925 transceiver, which combines the functionality of the WTR1625L and WFR1620 into a single chip and moves from a 65nm RF process to a 28nm one. Given that likely constitutes a significant savings in board space and power consumption, it seems likely that some combination of volume availability, price and time to design prevented Apple from implementing it this time around. The WTR3925 is just one piece of what Qualcomm calls their "RF360" set of RF front-end solutions. Also in that series are QFE11xx envelope trackers, QFE15xx dynamic antenna matching tuner (that is intended to address impedance changers from user handling, for example), QFE23xx power amplifier and antenna switch modules, and the QFE27xx which integrates the QFE23xx with filters and duplexers on the same module.Apple's competitors HTC and Samsung have implemented part of these solutions, with Samsung using a QFE11xx variant in their Galaxy S5 and HTC using that and a QFE15xx in their HTC One M8. ZTE intends to use the QFE23xx power amplifier line. Samsung's forthcoming Galaxy Alpha/S5 Prime is rumored to include the 9635 modem, which implies it would also use the WTR3925L transceiver. Of all the RF360 options, I believe Apple is using a QFE11xx envelope tracker variant, which allows them to dynamically adjust the supply voltage to power amplifiers based on the amplitude of the waveform being processed, saving power in the process. This supposition is explained in the PCB analysis section. The lack of other components is not necessarily troubling, given Apple tends to use power amplifiers, filters, switches, duplexers, and antenna switches from capable vendors like Skyworks, Avago, Murata, TriQuint, and RF Micro Devices.Going forward, further use of Qualcomm's latest solutions should not be taken for granted. Apple has recently taken to hiring engineers from baseband developer Broadcom , indicating they could intend to develop their own custom baseband solution. A more mild interpretation could be that they simply wish to develop more expertise in the field or expand their patent portfolio to give them ammunition in patent disputes covering wireless communications. Given the number of reports that Apple is always looking to diversify their suppliers to avoid risk, it makes sense that they may not want to depend on Qualcomm forever.Last year, I discussed the possibility of Apple improving over the iPhone 5's support of the IEEE 802.11N WiFi standard by including support for the AC standard, such as offered by the Broadcom BCM4335 solution. It is not surprising that they did not include support for it, given they have tended to be somewhat slow in adoption WiFi standards in the iPhone. For example, the 4S only supported 2.4GHz N and the iPhone 5 introduced 5GHz N. In fact, it wasn't until late May of last year that Broadcom announced a solution suitable for a mobile device such as the iPhone that includes all of the front end components. Apple has traditionally gone to Murata for their repackaged Broadcom solutions, and Murata does have an existing implementation of the BCM4339 solution.While that, with the expanded footprint on the PCB for the WiFi, may be enough evidence to believe AC support is coming, there had been the possibility that Apple could use a solution that combined WiFi, bluetooth and NFC into one module. NFC had been strongly rumored for several years, so that avenue is worth considering as well, given Broadcom does have such a product line . Fortunately, the populated PCB leak confirmed the presence of NFC in a dedicated chip by NXP, eliminating that possibility. With no new Bluetooth standard to adopt, the AC WiFi standard seems to be the only possible explanation for the module growth seen on the iPhone 6 PCB.After years and dozens of rumors, it appears the iPhone is finally getting NFC. The chip, which has 49 pins according to the bare logic board, also confirmed by the leaked schematic , appears to be similar to the NFC chip featured in the Samsung Galaxy S5 phone. What becomes interesting now is not the chip itself, but how Apple will include the antenna, or more accurately, inductor , in the design of the iPhone 6.In May of this year, an Apple patent was revealed that suggested the body of the device itself could be used for the NFC antenna, just as the body is part of the antenna structure for cellular, WiFi and bluetooth signals currently. This seems the most likely route, as Samsung's method of placing it on the battery is infeasible with an all-metal body that would block the transmission of signals through the device's shell. More recently, HTC put a NFC antenna in the opening for the camera while maintaining the all metal body. Given that assembled body pieces of the iPhone 6 has also proved this infeasible, we are left with the device using the traditional antenna structures or using the front chin or top of the device where the antenna could be embedded out of view but also not behind a metal structure that would block signals. Given that the patent seems to suggest the former, that is the best assumption moving forward.Last year, the excellent iPhone 5S rumor roundup from MacRumors shed 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 two years 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. Previously, apple had also done a maximum storage bump on every "S" model (3GS introduced 32GB, 4S introduced 64GB), making this one seem perhaps overdue. 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 $499iPhone? 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.Fortunately, this year we've been gifted with some leaked schematics covering multiple topics, including NAND storage. The first one was suspect, however, when it showed what appeared to be a 1GB NAND module. This was briefly interpreted as DRAM for a brief period because of the small size. Obviously, there will be no 1GB NAND storage option, so what does it mean? First, I should say that I started being highly skeptical of these schematic leaks. Technically, a designer like Apple can give a manufacturer layout design files and a netlist, and that will be sufficient to build the design. Design schematics often indicate functionality intent to the extent that they could inform competitors how to design things, so it seems unlikely that Apple would even share these outside of their own internal structure.However, subsequent leaks show a barometric pressure sensor , whose potential location on the board may have been identified, as seen in the PCB section. There was also a leak showing the correct number of pins for the NFC chip, again adding legitimacy to this source of leaks. Thus, if we are to seriously consider this leak, there seem to be three possibilities. The first possibility is that there is an extra NAND chip on the PCB. The bare and populated PCBs do not seem to support that claim. Another possibility is that it is included in the NAND module itself, as a separate memory module. The final option is that it is included in the AP package itself. If either of these is the case, we must realize then we are looking at schematics of those packages themselves, rather than the PCB. This gives me another level of skepticism, since it means those schematics are being shared as well. This assumes that the designers for these parts even produce schematics for them.So, if this NAND module does exist, what is its potential purpose? The second leak, that gives realistic storage values, also gives the context. If you look at the top right of both schematics, you see they have pins labeled "CE0" and "CEN0". These are chip enable pins. If you are going to have memory devices share a bus, you would route signals to them such that they could be enabled independently and either control the bus themselves free from contention from the other memory device, or to ignore the incoming write data not intended for them. In this case, the format of the net names is similar, with one net name containing "ANC0" and the other containing "ANC1". The net names on the IO of both are also identical, suggesting they do indeed share a data bus. The first NAND schematic also contains the word "POP" in the name, which could refer to the term Package-On-Package, which is how the DRAM is put into the AP package, for example.Given the details seem logically consistent, what could be the purpose of this memory? My guess is that it is a separate, small pool of memory that is likely encrypted and intended to store health and fingerprint data for the processor. Apple told us that the A7 had a "secure enclave" for fingerprint data, but if they also intend to gather health data as iOS 8 suggests, privacy concerns would also accompany that. Thus, if this leak is legitimate, that seems the most likely answer to me, regardless of whether this additional NAND is in the AP package or the main NAND storage package. In this context, it is also worth mentioning that no package pinout matching that of the M7 from the iPhone 5S logic board appears to be on the iPhone 6 PCB. As is explained elsewhere in the fixed function blocks, it is possible it moved onto the processor package, changed package style, or got integrated with some other function or package.Getting back to the second leak to wrap up, we see the table shows 16GB, 64GB and 128GB options. It seemingly answers both the question of whether a 128GB model will exist, and what the pricing tier will look like. It also becomes more interesting if the storage options differ across the two screen sizes, as has been suggested Perhaps the most anticipated aspect of this year's iPhone update, multiple leaks seem to have confirmed that 4.7 and 5.5 inch screen versions are coming this year, along with several guesses as to how Apple may achieve this with the impacts of pixel density with existing developer assets in mind. This seems likely a response to market pressure, as demand is very high for larger screen size iPhones. Rumors also suggest Apple is acutely aware of this, placing unprecedented order amounts for the new iPhones. Thus, the offerings of these new screen sizes seem all but confirmed. Apple seemingly maintaining pixel density, at least for the 4.7 inch version, also makes sense in that Apple clearly defined that they believe 326PPI is the benchmark for pixels the human eye cannot resolve. This would make any increase above that inconsequential to experience, and ultimately damaging to battery life as it is harder to drive more pixels.What is less obvious about these screens are what, if any, technology changes enhance their performance in metrics such as thickness, color gamut, brightness, or power consumption. One rumor suggests that Apple may use thinner LED backlights, supporting their overall thinness effort. Supposedly, the effort to reduce the backlight film to one layer from two caused production issues, suggesting several thinning efforts have occurred regarding the backlight. There have also been rumors of potential adoption of an alternative to the current in-cell technology termed "touch-on display", but it is unclear if that effort is still in effect.While there are clear efforts to reduce the thickness of the display and improve usability, there are no clear examples of efforts to improve quality. When the current display debuted in the iPhone 5, it was described by DisplayMate as the best ever. That crown has since been usurped by the screen of the Samsung Galaxy S5. OLED has clearly overcome its early challenges, the worst of which of was color accuracy. This has happened with the iPad too. For example, the iPad mini with Retina display recently made the change to IGZO transistors , whereas their direct competitors the HDX 7 and the New Nexus 7 are using superior backlighting methods, such as Quantum Dots in the HDX, or a LTPS backplane in the Nexus 7, which is the same power efficient backplane used in iPhones. In that comparison, the HDX manages the best overall rating while having an inferior backplane material to all options and having a better power efficiency than the iPad display.It will be interesting to see Apple's actions going forward as they have often been at the forefront of display quality, starting with the Retina display in the iPhone 4. If they are simply quality focused, we may see them shift to a new technology such as OLED regardless of the fact that the supplier may be Samsung. I believe Apple's past actions support that quality focus and the drive to avoid Samsung may be a bit overblown. It is also possible that could look to more exotic display technologies in the future, such as Quantum Dot displays. The term Quantum Dot actually refers to the backlighting method, and they can be used as replacements for LED backlighting in conventional LCD displays. They can help boost color accuracy, gamut, contrast, efficiency among many other improvements. DisplayMate has a good summary of display technologies that are new to or close to market in 2014. Fortunately, Apple is looking into Quantum Dot displays, but cite concerns over toxicity, cost and optimized performance. Thus, for the time being, it seems like we can expect IPS, LTPS displays with LED backlighting in all iPhone models.Looking outside the display itself, one 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.Apple has also made other moves in terms of acquisitions and partnerships, acquiring LuxVue Technologies , a company that specializes in low-power displays. LuxVue has also developed a technology called "microLED", which promise brighter and more efficient screens, making that another alternative for improved overall display performance. They've also partnered with a company called Pixelworks , whose technology can supposedly enhance color, sharpness, contrast, and de-blur. They also claim their technology can extend battery life, all of which would be a strong interest of Apple's. Finally, Apple also tried to acquire the Renesas SP Driver division, in hopes of bringing display driver technology in house. That division was acquired by Synaptics instead, perhaps suggesting that the purchase wasn't essential to Apple's vision moving forward. Therefore, it does seem clear that Apple has a distinct vision on how to improve their display products, albeit possibly arriving later rather than sooner.Finally, we come to Apple's heavily rumored use of sapphire in their display panels. While sapphire is more scratch resistant and stronger than gorilla glass, it is also more brittle, making it susceptible to drops. Analysts cannot seem to agree when and if it is coming to iPhone displays. It has also been labeled as more expensive. Given the nature of the product is imperceptible to the user until an accident happens, it seems more of a curiosity to the average user than a truly compelling upgrade that improves the average user experience.Stories have circulated that Apple could be looking into adding high quality 24-bit audio files to its iTunes library. They already suggest that artists submit 24 bit masters as part of their "Mastered for iTunes" program. Demand for high quality audio may be growing too, with the rise of premium headphone brands recently, including Apple's acquisition of perhaps the most notable brand, Beats. Last year, LG suggest a larger internal speaker for the next iPhone. While perhaps not the preferred method of entertainment audio delivery and more important for voice communication, it does at least indicate that they are not content to stagnate on audio all together.Apple, through the use of their MFi Made for iPhone program, has allowed 3rd party manufactures to access the digital audio stream of music through the lightning connector. This allows manufacturers to potentially interface higher quality DACs and amplifiers with the iPhone, albeit at 16 bit depth that the iPhone is limited to. Perhaps this is one avenue that Apple can exploit with Beats audio products, including a DAC and amp directly into the headset and having it connect via the lightning connector rather than the standard audio jack.Two years ago 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 5S battery capacity is 1560 mAh. There have been a total of four leaks for the iPhone 6 battery, the first two of which suggested 1810 mAh for the 4.7" version, while the third suggested 2100 mAh. The only leak for the 5.5" version has suggested 2915 mAh. These are all significant bumps, and are the biggest jumps 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).As you can see in just about any android battery life profiler, the screen is the single biggest user of battery in a smartphone. Thus, with the screen sizes increasing dramatically on the iPhone 6, a large step in battery was necessary to at least keep pace with the increased battery life demand from the screen. If the larger 2100 mAh battery size is true for the 4.7" version, Apple appears to at least have done that.One can see in the rumor roundup that the pill shaped "True Tone" flash has changed into a circular shape, like previous iPhone flashes. There have been a few rumors regarding the back camera of the device, with one suggesting Apple would again use a Sony IMX sensor, this time at 13MP. Another application was published in January for an OIS implementation. One rumor suggests that the 5.5" model alone will get OIS, and it will be a differentiating factor between the versions in addition to screen and battery size. The iPhone 5S already features software image stabilization, but hardware based image stabilization would no doubt be a step up. Leaks also suggest that at least the 4.7 inch version will feature a [URL="https://www.macrumors.com/2014/08/20/alleged-schematic-protruding-camera-4-7-iphone-6]protruding[/URL] camera ring as iPhones become thinner and thinner despite the relationship of optic assembly depth and overall photo quality.Chipworks, an advanced teardown and analysis research firm, has their own [URL="http://www.chipworks.com/en/technical-competitive-analysis/resources/blog/iphones-cameras-whats-coming-in-the-iphone-6/?lang=en&Itemid=815]thoughts[/URL], suggesting the total MP count increase will be modest if at all existent. They also suggest that the new camera may see the addition of on-chip phase detection pixels which enable faster autofocus. They also address the front image sensor, which other rumors have not touched on, suggesting it could increase to 2MP and see a supplier switch from Omnivision to Sony. The article is brief and also has good charts showing the evolution of iPhone front and rear-facing cameras and is a recommended read.One thing that is certain is that Apple has always stressed the quality of images over touting impressive spec numbers when it comes to camera performance, so I would not anticipate a large MP boost or a decrease in pixel size.