Reading 90% of the articles about this subject over the past few years (aside from the plethora of “Will / won’t the next iPhone have NFC” stories), you could be forgiven for thinking that NFC was just a way of putting a payment card in your phone.

Mobile contactless payment is a great piece of functionality and one which many of us (myself included) have been longing for but it’s hardly new: Japan has had it for years, with the FeLiCa system embedded in most handsets. It’s well-liked, trusted and very broadly accepted. Over here, the main hurdles have been political rather than technical.

Payment is a fascinating story on its own and it’s very tough to predict who will come up with the dominant solution, but we decided to write a series of articles about some other aspects of NFC to demonstrate how it’s capable of so much more.

What we have been pondering is: assuming that phones have NFC capabilities, what does that allow you to achieve outside of the holy trinity of:

1. Payments
2. Transport / event tickets
3. Vouchers / loyalty cards.

Some of these other use cases are well-known today, such as key tags for access control systems (door locks), and others will become better known soon, such as NFC-based check-ins for location-based services such as FourSquare.

It’s our belief that NFC is far from another gimmick and has the potential to actually change the way we interact with the physical world in a profound fashion.

This series of articles will dig further into these areas and look at what can be done, the challenges faced and some possible ways that they could be achieved.

What’s coming up?

Coming soon, we look at how NFC can improve the top-up method for pre-pay mobile phones, help people with hearing and sight difficulties, stop your washing machine annoying you, make your trips to shops and restaurants faster, improve your product selection experience, share media around the home, expand the functionality of products, improve user interfaces and allow you to build great cross-platform libraries.

But first, it would be slightly crazy of us not to even glance at the world of NFC payments: it’s going to be the most commonly known use for NFC and the main focus of all the companies involved for the next few years.

NFC payments – at last! But how?

Finally, operators and handset manufacturers across the world have started to take proximity communications seriously and are in a land grab battle to become the controlling point of a new mobile handset-based payment system. Everything Everywhere, in the UK, have announced their NFC trial on their Orange brand in the past few days and Apple are widely expected to add this to the iPhone soon.

Will it be the credit card companies through plug-in NFC dongles such as phone jackets or MicroSD cards, the handset manufacturers and platform vendors through on-device “secure element” chips or mobile operators through NFC SIM cards which will form the dominant payment infrastructure?

It’s a tough one to call: each has strengths although the dongle approach is arguably the weakest of the three. Platform vendors could have a big say in this by what they permit to run on their OS: will Google permit operators to sell Android phones which disable the Google Wallet functionality and replace it with their own software and SIM card NFC secure element?

But, if this does not resolve itself soon, there looks set to be a great deal of fragmentation with incompatible solutions across the world and even between different operators, OS, device and payment card vendors within a country. Yikes.

Why NFC payments?

This is the most economically significant reason to invest in an NFC infrastructure. I won’t go too much into depth or re-hash what is common knowledge but will give you a quick set of bullet points to give you food for thought.

1) People using contactless payment technologies spend more money.

Partly this is down to a lack of visibility of how much you’ve spent but, less intuitively, studies showed that there was a significant barrier to buying a low cost item if you only had a large note – people didn’t want to break into it and have to carry around all the change.

2) Cash is very expensive.

Especially with the costs of raw materials rocketing in recent years, some currencies have ended up in the situation where coins were worth more melted down to raw materials than they were as legal tender! Manufacturing cash, securing it, transporting it, destroying it, validating it, storing it and processing it adds massive costs to businesses, banks, transport networks and vending machines.

3) Cash is money not being used.

When that money is sat their in your wallet, nobody is getting any value from it – this goes for shops, banks and people alike. Casinos gained massively by moving from cash to ticket-based systems, helping security and improving cash flow.

4) Fraud is on the up.

Counterfeiters are getting better and better at faking coins and notes: in 2009, the bank of England found about £11 million of fake £20 notes and they estimate that there are some 30-40 million fake £1 coins in circulation at any time.

5) It’s cool!

Seriously, it’s great: it’s better than cash in pretty much every way imaginable. It’s faster. You can do many new things: track your spending, not lose it down your sofa and compartmentalise money for different purposes. You’ll love this: Steve Jobs would describe it as magical, where the technology disappears and doesn’t get in the way of the experience, allowing you to do things which seemed impossible.

So, yes, NFC payments will be a big game changer and I, for one, can’t wait to get rid of my wallet. But the technology is capable of so much more and that’s what we’re going to be writing about and demonstrating over the next few weeks.

But, as measured by DisplayMate, the original Droid series had one of the best displays in a phone ever seen, with comparably high resolution and better colour reproduction than an iPhone4 display. Was this a display in need of changing?

And has the shift to a qHD Pentile display (540×960) been worthwhile for Motorola; should you buy one?

In a word, no.

Even by my usual standards, that’s an uncharacteristically blunt answer.

But why? Surely the Droid X and Atrix / X2 use the same size screen (4.3″ diagonal) but have 518,400 pixels instead of their older brother’s 409,920 pixels. That has to be better, right?

Wrong.

In our earlier article about the new Pentile RGBG displays, we pointed out that these displays had a resolution effectively 1.41 times lower than their headline one as the patterns which your eye could see were rotated 45 degrees from the main grid and expanded.

The new displays have 1,036,800 dots whereas the old ones have 1,229,760. Hold on, they have fewer dots?! Well, how can they have more dots per inch!?

They don’t.

The purple lines on this show the outline of the pixels and the black lines show the grid made out by the sub-pixels (white in this case)

But it’s definitely a higher resolution on paper – surely this is a clear win, right?! But, hang on, how about that whole issue of the Pentile layout?

On paper, the Pentile qHD display is 12.5% higher resolution than the earlier display but, in reality, your eyes see patterns which make the screen look like one that has 20% lower resolution than the older display.

Furthermore, the patterns you can see are considerably worse than the patterns you can’t see are better. aka, overall, it’s worse.

So, pick a new qHD Motorola phone because it has higher light efficiency, brightness and battery life but not because it has higher resolution: it’s actually a step backwards as far as effective resolution is concerned.

So, could AMD be about to give up their crown jewels, x86, and jump ship to ARM to compete in the growing smartphone and tablet markets with dozens of other chipset manufacturers?

Well, AMD say no, but had previously been speaking in somewhat coded terms and have followed this up with several very vague comments about no doors being closed. With no permanent CEO in place, it seems unlikely that such a strategic decision could have been made in the past few months but why should (or shouldn’t) AMD consider bringing out an ARM chip in theory, if they haven’t decided this already behind closed doors?

We’ll have a look at if this is a sensible plan or whether they may be trying to buy some time: announcing new ARM products may well hurt their current product offerings and roadmap, yet delivering a whole new CPU architecture on a new instruction set takes a long time and, if they were to have only started recently, they would be some years away from hitting real products.

x86‘s past

In the past, AMD’s main strength has been its x86 licence which has allowed it to run Microsoft’s Windows and the vast library of applications available for that, letting them compete against Intel for the high ASPs, decent margins and good volumes offered in the PC world.

VIA, Cyrix, Rise, IBM, IDT, Transmeta and others who previously sold x86 processors have effectively fallen to the side leaving a virtual duopoly of Intel and AMD; even AMD looked to be on shaky ground until new investors from Saudi Arabia spun off their manufacturing division and Intel paid them $1.25 billion to settle a massive anti-trust legal case.

In recent years, ARM tried to break into the PC market, showing off tiny, low-cost netbook-competitors to little effect. Qualcomm invested large amounts in promoting their SmartBook concept and, again, failed. Why? No O/S. No apps: no Office, no IE, no iTunes, no Photoshop, no Firefox, no Flash.

It didn’t matter what chip you had inside your product: if you released something which looked like a notebook PC, people expected Windows. Linux was not ready for the unwashed masses, as Acer discovered with their first EeePC models, where the Linux ones were sent right back to the stores they were bought from.

But times have changed, with the iPad redefining what was needed from a computing device and with Microsoft announcing that future versions of Windows would run on ARM as well as x86 – the first open, dual-architecture consumer platform in the desktop Windows range. Even Apple are rumoured to be making a switch to ARM so maybe the time is right now?

Market followers?

In fast-shifting industries, being behind the cutting edge can both be a blessing and a curse. It’s frequent that the first to market has failed to make the most of their position and become dominant. But missing the boat altogether is categorically a course for disaster.

It’s not too controversial to suggest that AMD have traditionally followed Intel’s lead, with the exception of a period where their K7 and K8 chips led the way with innovations including bringing 64-bit x86 extensions, on-die memory controllers, Silicon-on-Insulator and monolithic dual core CPUs to the mainstream.

AMD's Athlon 64 x2: the world's first monolithic dual core x86 processor, with a 64-bit ISA and SOI manufacturing

Sadly for them, they failed to translate this period of strength into a transformation of the company into a genuine leader in the x86 field, appearing uncomfortable with their new standing and misfiring on several follow-up products, even allegedly ripping up major parts of their roadmap (such as the K9) and allowing Intel to spectacularly re-capture the performance lead with their Core 2 microarchitecture.

AMD have also often been 12-24 months behind Intel with manufacturing, support for new instruction sets, features and overall performance; they have usually achieved sales through lower prices, Just Good Enough performance and fewer restrictions.

For example, while an excellent product, AMD’s competitive answer to Intel’s Atom (Fusion) only hit the market in late 2010: more than two whole years after products using the Atom first went on sale in early 2008 and after the sales of netbooks (Atom’s bread and butter) had started to decline. Before this, they focused the majority of their efforts on desktop chips just as the world was shifting to laptops.

The technology world sadly has many examples of boats that AMD managed to miss. Is mobile to be another of these?

All change

The tides of the technology world have shown major signs of shifting, with Intel announcing today their new focus on mobile, and, while traditional PC products still account for massive volumes, the momentum is certainly with mobile-derived products at the moment. Here, AMD have already missed out yet again, having sold off their ultra-low power CPU division to Raza and ATI’s mobile graphics division to Qualcomm, ironically forming one of their strongest competitors today.

It’s almost certain that CEO Dirk Meyer’s departure was not just down to delayed execution on their “Fusion” products, Atom’s competitor, but that he had failed to provide a competitor for the smartphone and tablet markets, where all the growth was. Certainly, AMD’s executives are on record as desiring a big piece of the tablet market.

Where’s the software?

While AMD’s Fusion products look to be a good fit, hardware-wise, for tablet products (and their 28nm follow-up products even more so), they now find themselves on the wrong side of the software fence: with Microsoft’s tablet strategy backfiring so badly, AMD’s x86-compatibility is now a liability in the world of mobile Operating Systems and applications, designed to run on the ARM architecture.

This has allowed competitors Qualcomm, Broadcom, Mediatek, Marvell, TI, Freescale and OEMs like Apple and Samsung to produce chips for personal computing devices (that’s with a small P and C) and fight for the business amongst each other with both Intel and AMD sidelined like never before.

Look at the rate of new ARM apps appearing on iOS and Android compared to x86-compiled ones in the world of desktop Windows and Mac OS X. Even bringing the App Store model to OS X does not appear to have delivered the same explosive growth and innovation as in mobile.

App store statistics, February 2011. (c) Copyright Distimo http://www.distimo.com/publications

In a nutshell, unless they go ARM, AMD currently desperately need a successful mobile operating system with apps for their x86 chips to be relevant in this new world. For that reason, AMD joined MeeGo which, with Intel and Nokia on board and a very different set of values to the relatively locked down iOS and Android (for good or bad) providing strong diffentation, looked to have a decent chance of success.

Nokia’s departure from MeeGo appears to have effectively closed the door on that operating system as a competitive mobile OS which runs equally on ARM and x86. If MeeGo does indeed fail, it will hurt both Intel and AMD.

So how about Android? Well, even on Android, despite having many apps written in cross-platform Java, x86 is incompatible with the kind of apps for which high-performance CPUs would most be of benefit, which have been developed using Android’s NDK (Native Development Kit) and compiled into ARM code.

Categorically, these apps (which include many games like Angry Birds, augmented reality and other performance-dependent apps) will not run on an x86 chip unless some form of emulator is provided which would hurt the performance.

If Intel’s current strategy does work and they do manage to bring the momentum to x86 in mobile, then AMD will be OK with continuing on today’s path. But that’s by no means guaranteed and it’s a mighty risky strategy to rely so much on your main competitor. By shifting to ARM, if the x86 in mobile strategy fails, AMD would at the very least have a head start on their main competitor if Intel also were forced to shift.

How would / should AMD differentiate if they go ARM?

Let’s make no qualms, there is little overlap between x86 and ARM in CPU performance at the present moment. The highest performance ARM CPU core at the moment is the Cortex-A9 with Qualcomm’s Scorpion not far behind. The next generation scorpion core will undoubtedly reclaim the lead and ARM’s Cortex-A15 will respond to that. But even the fastest quad core Cortex-A9 will be nowhere near Intel or AMD’s finest.

There are valid reasons for this, but the x86 competitors currently occupy a higher space in terms of raw performance. AMD and nVidia also hold a staggering advantage in graphics performance which is bound to the x86 world at present. Good benchmarks to compare these two worlds don’t even exist yet, the chasm is still so large.

Graphics chips are also now able to handle more general purpose code through APIs such as OpenCL. This reduces the impact of the CPU ISA and makes the change even easier.

Naturally, therefore, the obvious space for AMD to occupy would be above the existing players. Want the ultimate in low power? An AMD ARM chip may not be the right choice. But, if you can cope with slightly higher power consumption (like an ultra-thin laptop) then you are not so restricted and a 5-10W ARM chip with class-leading CPU and graphics performance may be perfectly acceptable. They have working relationships with every major OEM and plenty of manufacturing capacity and experience.

Pick a spot at the top and they can choose their price and cream off the profits from the industry, leaving others to fight with the low cost base companies like MediaTek.

But a System-on-Chip is not so much a musical instrument as an orchestra: it’s not all just about the CPU and GPU, but having a balanced ensemble of components with no obvious weak link such as an out-of-tune trumpeter screeching over the otherwise beautiful sound. In the x86 world, it’s not just the CPU that takes more power – it’s almost every single component. There are also many unknowns for AMD moving into this field – image processors, DSPs, on-chip power management, security… Clearly, there is a lot of work to be done to reach the balance and create a desirable SOC.

AMD are on the right lines with their Fusion products which are very comparable in silicon size with the latest ARM products from nVidia, Samsung, Qualcomm and ARM, but there’s still a big gap in active power consumption and an even bigger one in idle / standby power.

AMD’s options

For AMD to abandon x86 for the PC market would be foolish, unthinkable; that is certain. It may be a good few years before the mobile architectures start to seriously impact the PC world.

Like it or not, however, the SOCs are coming for their main market, at a lower price and with much more software. If they choose not to respond with an ARM product, AMD risk choosing not to take part in the future.

Taking on an ARM architecture licence and designing a higher performance core to combine with their leading graphics architectures would be no different from what they do today: taking an x86 licence from Intel and trying to design a higher performance core. It would, however, be lower cost, easier to win and come without any kind of onerous licensing terms.

This is a classic situation where hedging your bets is the best strategy by far: at present AMD’s market share in tablets and mobile phones is 0%. The only way would be up.

This is an amazing breakthrough and they should be thoroughly congratulated as should, if rumours are true, LG who are also likely set to announce something similar.

Less well-received was the news that this product would see the return of the sub-pixel layout known as Pentile: a trick where, for the sake of increasing perceived resolution and effectively shrinking the pixels, part of the colour information for each pixel is thrown away.

The OLED displays used by many HTC and Samsung handsets used this technique, resulting in many users complaining of a graininess to the screen and jagged edges on text and UI components, just like you’d see on older digital camera displays.

Digital Camera LCD screen showing jagged edges caused by RGB Delta sub-pixel layout.

Digital Cameras didn’t actually use Pentile, but often used another layout called RGB Delta, with the red, green and blue arranged in triangles. But why? Well, RGB stripe, the conventional approach for computers and smartphones, has its failings too, particularly when displaying softer, natural content like photographs. The camera makers chose RGB Delta because it was, in fact, better for displaying the pictures and that was the top priority.

So should you want a new Pentile LCD display in your next tablet computer, even if it has a high resolution? It’s clearly not a simple answer so that’s what we’re here to dig into.

White sub-pixels

Differentiating itself from the OLED displays which Samsung  produced, with RGBG layout (two greens to each red or blue sub-pixel), the new tablet screens have introduced a white sub-pixel in place of one of the greens.

Since white can be formed by adding Red, Green and Blue together, why would they go to the effort of putting an extra white sub-pixel in, increasing the complexity? Well, the reasons are, on an LCD display, efficiency and brightness.

Most colour LCDs (with the exception of field-sequential designs, such as on Sony’s NGX-VG10 HD camcorder) create colour by passing white light from the backlight through a colour filter, blocking a large amount of the light from passing in order to generate the different colours.

Unlike TVs, smartphone and tablet displays spend much time showing content with a white background, such as documents and web pages.

Adding a dedicated white sub-pixel helps with these bright screen scenarios because, with no colour filter over the top, you increase the amount of light which comes through, even with the same backlight behind it – each pixel becomes much brighter! Because of this you can also make the colour filter over the other sub-pixels more aggressive in order to produce more vivid colours.

On a mobile product, there’s a further bonus advantage to this: mobile displays tend to be partly transflective. Try turning your phone’s LCD backlight down and look at your display in bright sunlight, moving it around different angles. It may surprise you to find that there are some angles wich you can hold it in where the display is still very readable – that’s down to reflected light from deep inside the display. The Nokia E6x series had particularly good displays for this.

Reflected light has to pass through the colour filter twice: both going into the display and coming out, cutting down the brightness twice. Removing that helps with transflective operation so the new tablet screens have the potential to be much better in direct sunlight than their predecessors.

So far, so good, then. Better colours, better battery life, brighter displays and better performance outdoors. So what’s the downside?

Pentile returns

I regard the Pentile pixel layout as cheating. It’s a clever cheat and, for reasons to be explained, not necessarily inherently “A Bad Thing”, but a cheat it is.

Why would you use Pentile? Well, by reducing the number of sub-pixels by 1/3rd (and making the shape somewhat easier to manufacture than the long thin rectangles of RGB stripe), you can pretend that you have more pixels on the screen and, to be fair, you do get some of the benefits of higher resolution. But not all of them and there are drawbacks.

The Pentile Blog, run by the company who invented and licence the technology (who Samsung acquired), attempts to tackle the question head on with their post “Does PenTile have Fewer Pixels“. To quote from this article, their answer is simple: “Pfff… No. PenTile has the same number of pixels as a legacy stripe panel.”

Hang on RGB stripe panels are “legacy”? I thought that RGB stripe was a new feature only available in the latest “Super AMOLED Plus” displays on the Galaxy S II; that’s what the “Plus” stands for after all! Apparently, RGB Stripe is a good feature when it’s in a Samsung display and a bad one when it’s not.

Anyway, in this strange world, all pixels are not equal. A pixel (a point of light) has a colour associated with it. Pentile pixels are normally not the correct colour. On an RGBG Pentile display, the colour of pretty much every pixel will be fundamentally incorrect because each is missing either all the Red or all the Blue data. It’s up to the adjacent pixels to try to add that missing information.

The two different types of pixel in a RGBW Pentile display. The first can only contain hues made from red and green, the right only mixtures of blue and white.

Essentially, the Pentile system compresses (lossily) the colour data, saying that it’s not that important because the sharpness remains, as shown by an ISO test which claims that they are visually comparable from a distance.

To me, that is equivalent to selling a “32GB Flash Disk” that’s really only 22GB and the manufacturer tries to justify that by stating that you can store 32GB of Zipped Word Documents. It’s somewhat dishonest.

Many people saw straight through this when they realised that their displays were not showing the level of detail they expected and had odd visual artifacts. That’s why there was such relief when Samsung appeared to have reverted to the earlier and more loved layout with the Galaxy S II and other phones.

So, is RGBW any different to this or does it also throw away colour data in every pixel? No, it’s not really any different. Half the pixels still have no Blue information and the other half have very little Red or Green (other than what’s in the white sub-pixel). RGBW has some advantages, as said above, but Pentile is still Pentile.

Graininess

But it’s not the lack of colour information which most people complain about. The clever maths is solid and it averages out to look close to the original picture. In fact, on a photograph or video, you may well be hard-pressed to tell the difference between the displays.

What is most obvious, though, is a side-effect of having to deal with the lack of colour information, whenever you look at text or user interfaces.

Consider the layout of these three display types: RGB Stripe, RGBG Pentile (as on many AMOLEDs) and RGBW Pentile (as on these new LCDs).

One way of laying out a screen with 1/3rd the colour information missing could be to stick to stripes.

The problem with that is that the oddness of the missing colour information would be very easy to spot – big stripes running down the screen of alternating purple and green hues so, naturally, the alternative is to break the pattern up and alternate the order between the rows of the display.

So we end up with this:

Sub-pixel layouts compared

Looking at these, you can see two things instantly: 1) The RGBW looks instantly brighter – as we predicted – and 2) The staggered rows gives a sort of checkerboard effect that’s much lower resolution than the pixels, so is much easier to spot to the naked eye. Remember, according to the Pentile proponents, the three images above are all directly equivalent, despite the obvious lower level of detail in the Pentile layouts.

It’s this checkerboard pattern which gives the graininess to solid areas of colour which is so noticeable on many Pentile displays. But it’s not just the graininess, it’s also the fact that edges which appear straight on a RGB stripe display will appear jagged, with odd pixels sticking out, just like on those old camera screens, and vertical lines will zig-zag across the screen.

Now that’s all well and good, but how does it affect real-world performance? Here is a close-up shot of a RGBW display from AnandTech’s Motorola Atrix 4G preview.

You don’t need to be a display expert so see that the graininess is still there, as are the jagged edges. RGBW didn’t solve this problem.

Simulated performance

On Twitter, Engadget’s Richard Lai pointed out to me that he would be interested to see how the technologies compared at the same resolutions.

Sadly, I wasn’t able to get the different display types today to do a direct comparison so here are some mock-ups I made to demonstrate what’s going on with different types of content. These pictures pretty much speak for themselves. They have been slightly blurred to simulate the impact of your eye (all adjusted by an equal amount),

Text	Lines
White text on black background compared on RGBW, RGBG Pentile and RGB Stripe displays	2 pixel wide vertical stripes in Blue, Grey and Red compared on RGBW, RGBG Pentile and RGB Stripe Displays
Dark Text	Photogaphs
Black text on white background on RGBW, RGBG Pentile and RGB Stripe displays	Photographic content on RGBW, RGBG Pentile and RGB Stripe displays

Interpreting these pictures is somewhat subjective, but there are a few observations from the above pictures which I hope you will agree with:

1. Looking at the text, the higher resolution and more uniform pattern of the RGB stripe makes the text look much cleaner. Stray red sub-pixels on the vertical edges of the letters look messy; the white background makes things worse. The white sub-pixels of the RGBW arrangement stand out quite prominently compared to RGBG, making the checkerboard effect worse.
2. On the lines, representative of UI components, the vertical lines exaggerate this stray pixel problem on both the Pentile layouts. When the line is only two pixels wide, you see the red and blue lines jump their way from one side to the other, zig-zagging its way down the screen as the colour information gets dropped.. But, on the grey colour, the RGBW layout looks quite a bit smoother than RGBG.
3. The photograph is the most interesting one: here, patterns in both layouts are very clearly visible. The RGB stripe does look most artificial, almost robotic and, well, stripey. That said, the checkerboarding is still very visible on the and the 50% higher resolution of the RGB stripe shines through too but it’s not a clear win for either.

Anand Lal Shimpi summarises it very well, again from his Atrix review:

“Personally, I was bothered a bit by text rendering (particularly aliased text on zoomed out web pages) on the qHD screen. For the most part, the qHD display was pleasant to look at and its PenTile upbringings didn’t bother me.”

A subjective difference?

Here we get into the territory of “Retina” displays and the ilk: at what level will all these pixels (and, of course the sub-pixels) blur together, rendering all arguments about jagged edges and visible patterns moot.

For every person, this point will be different, depending on a) the dpi (dots per inch) of the display, b) how far away you hold it from your eyes and c) how good your eyesight is. Many people won’t ever have noticed this even on the worst Pentile screens.

For Pentile, the checkerboard pattern has an interesting effect, because what is important for determining this visual dpi is the distance between the visual artifacts (the dots of the same colour), rather than the distance between adjacent “pixels”. This is much lower. In fact, looking at these dots, you see that the effective grid is rotated 45 degrees from the normal display angle and the gap between the subpixels is 1.41 times that implied by the quoted resolution.

The purple lines on this show the outline of the pixels and the black lines show the grid made out by the sub-pixels (white in this case). The black grid is 1.41 times wider than the purple one, yet your eyes pick this out very clearly, despite the data sheet quoting the figure for the purple grid.

A lot has been written on the subject of Apple’s Retina Display so I won’t re-hash this, but it’s worth doing a few quick sums on Samsung’s new panel just to see how it compares.

Now, at 300dpi, the pixel resolution is clearly right up there with what Apple claim to be “retina”-class, for a mobile phone screen. But, at 211dpi, will the checkerboard pattern could well be visible to many people.

In his article “Resolving the iPhone resolution“, Phil Plait uses the assumption that people hold a phone around 12″ (30cm) away from their eyes. I did a quick check and arrived at pretty much that same distance for holding an iPad so the assumptions for DPI necessary to be “retina”-class in his analysis hold true for a tablet too.

“Let me make this clear: if you have perfect eyesight, then at one foot away the iPhone 4?s pixels are resolved. The picture will look pixellated. If you have average eyesight, the picture will look just fine.”

Conclusions

Samsung’s new tablet display is retina-class, but many people may well still be able to detect the visual artifacts coming from the Pentile layout.

To fully get rid of the effects on a Pentile layout, you would need to increase the resolution to around 420dpi, which may mean that sticking to a 300dpi RGB-stripe display is the best solution.

Ultimately, if you think it will annoy you, you need to try it out to see if your eyes are sharp enough to spot the problem; if not, then don’t worry about it! But bear in mind, when you’ve seen this artifact, you will never unsee it.

If  you do end up getting a new retina class tablet with this Samsung display, then the addition of the white sub-pixel should have some really nice benefits to battery life, colour reproduction and outdoor performance, whcih are very good things.

I guess we’ll just have to wait and see what the rest of SID shows and what Apple turn up with in the next iPad!

Many commenters have been highly skeptical of this, verging on the angry denial.

Suicidal

After all, surely, that would be suicidal for Apple; even today’s best ARM chips are many times slower than Intel’s Sandy Bridge in terms of raw performance and it’s incredibly hard to shift all today’s software over to a new architecture, especially if the new platform is too slow to emulate the old one. Fancy running Photoshop CS5 in an emulator? No? Me neither.

Add in the fact that there are thousands of peripherals like printers and scanners which require drivers that are not available for Mac OS on ARM; should users just dump these?

So, would it be suicidal? Well, maybe and maybe not. In response to this, I posted the following answer on Quora and thought it would be interesting to post here with some additional detail.

In short, I believe not only that it’s plausible but that it’s actually hard to find solid arguments as to why it wouldn’t happen.

Could it happen?

A change of this magnitude could really only be completed several years out from now

Today, x86 still holds a large performance lead over ARM and while Mac OS has a large base of x86-only software and slow-moving partners in terms of taking advantage of the latest opportunities made available to developers, but it seems a possible long-term strategy for Apple to follow, unifying their platform.

Naturally, with ARM having already demonstrated such products (albeit, with no compelling software to run on them) the first product would seem likely to be a thin & light MacBook Air-style device often used as a secondary computer.

But why??

Well, one needs to look at some trends and indicators to spot why this is so likely:

The trends and indicators

1. Apple have not been afraid to jump architecture before. They have the know-how to do this.
2. Mac OS X is effectively already running on ARM in the form of iOS – it’s just a difference of form factor and performance at the moment, as well as compatibility with existing software.
3. Raw CPU performance is not as critical to overall performance as it once was, with a wide variety of specialised accelerators being part of a system to do the common jobs and bigger gains coming from technologies like SSDs.
4. iPads are proving capable of doing a large swathe of computing tasks for many people, causing a drop in netbook sales.
5. Apple see iOS as more important than Mac OS (for example, iOS has an SVP; Mac OS only a VP).
6. The cost savings of moving to an in-house CPU, chipset and GPU are huge (and they’ve already done that for the iOS devices). Do not underestimate how large these are!
7. Apple bought two CPU design-related companies and now manufacture tens of millions of processors every year.
8. There have been multiple adverts for CPU microarchitects recently posted under Apple’s “Mac Hardware” jobs section, not just the iPhone or iPod divisions.
9. Much of the momentum in the industry is with ARM at present, in terms of Operating Systems, critical software (like browsers and plugins) and hardware vendors. Most of the innovation in new software is on the web or mobile, not desktop operating systems. The Mac App Store on x86 has had far less success and holds far fewer titles than iOS on ARM.
10. OS X is becoming more iOS-like from Lion onwards.
11. Connections are becoming more wireless; drivers for peripherals are becoming less important. The future is in higher-level wireless protocols like AirPlay and AirPrint which are not specific to one device.
12. Apple aim to be vertically-integrated, able to control their own destiny and able to keep hold of their advantages. Buying in the main components of their computers from Intel, nVidia and AMD are contrary to this goal and lead to fiascos like the nVidia “bumpgate” recall on MacBook Pros.
13. XCode already compiles iOS apps to both x86 (for the simulator) and ARM (for the device) so it should be relatively simple to make a well-designed app run on both architectures. OS X universal binaries could support these in one package to ease distribution, just like they did before.

But ARM is slower, right?

It’s very hard for many people to see ARM chips outside of the context of its history in mobile but, ultimately, ARM is just an instruction set. While there are reasons why one ISA may be faster, smaller, easier to code for or more power-efficient than others at a certain power level, the main differences come from the constraints imposed on the chip designers by their target markets.

Only building a few thousand chips a year for devices with excellent cooling and vast power supplies, just to achieve maximum performance? Well, you can build a massive beast of a chip like Intel’s Itanium or IBM’s Power7. But you won’t be putting it in a mobile phone. Likewise, a CPU designed for a handheld gaming device won’t be ideal as a weather-predicting supercomputer.

Yes, it’s certainly undeniable that, today, ARM-based products are well-behind Intel and AMD’s finest on absolute performance but will that always be the case?

ARM chips have mainly been slower than x86 chips because they’ve been designed to be. They’ve been aimed at tiny, mobile devices and have had power and size constraints from that world… but there’s no reason they have to be. ARM are rumoured to have targeted their CPU cores as being no larger than 2.5mm² and using less than 0.25W.

What point was there for ARM to try to build a chip for the high-performance desktop market when all the software only ran on x86? Who would have bought it? Naturally, they focused on their main market: ultra-mobile and embedded devices.

Yet, Apple’s A5 chip is already bigger (in terms of silicon area) than competing x86 products from Intel and AMD – ARM’s ecosystem is starting to break out of this box with a vengeance so preconceptions need to be re-thought.

When it last sold on the desktop (in Acorn RiscPCs) ARM chips were often just as fast as Intel ones (if not faster in cases) but on the wrong side of the river in developer land, where no software was growing. As Steve Ballmer famously said, “Developers, developers, developers”

Really, ARM ended up in mobile as much out of luck and necessity as from a deliberate strategy initially (and, somewhat coincidentally, with the assistance of Apple for its Newton project).

But, now, it’s x86 which finds itself in the position where software looks to be stagnating and most of the growth is over on the other side of the river in ARM land (or on the web, where the client CPU architecture is largely irrelevant, excepting for plug-ins).

Expect things to change.

My best guess at how it will play out is something like this:

1. Apple announce that Mac OS X Lion will support ARM processors and start seeding the market with developer tools to recompile apps for this platform.
2. 2012/3 MacBook Air launches with a 28nm quad-core A6 processor based on Cortex-A9 or A15  that outperforms the existing Core 2 Duo in today’s MacBook Air. It runs native, ARM-compiled versions of iLife and iWork. Technology journalists criticise it for having too little CPU performance (just like they did to the previous MacBook Airs) and having a limited software library. Millions are sold anyway.
3. 2013/14 Apple hits the ground running with their own 64-bit ARM-compatible CPU designed from scratch for much higher performance, comparable to a mid-range x86 mobile chip and nVidia’s Project Denver, then pushes it out across most of their laptop range.
4. 2014/15, next generation architecture comes out, maybe even with multi-processor support, delivering good enough performance for the rest of their product range, enabling the transition to complete.

That’s just one possible scenario, of course: usual disclaimers apply, and there are any number of ways Apple could do this. The transtion from PowerPC to x86 was, after all, lightning fast.

But, by doing this, not only do they gain more control, gain a unified platform for software development, and gain the ability to produce thinner machines with better battery life, but they save literally hundreds of dollars on every Mac they ship.

Looking at today’s MacBook Air, up to $300 of the Bill of Materials cost may be assigned to the CPU, chipset, graphics and associated components according to list prices. iSuppli estimate that the Apple A5 chip costs $14 so, even if it were to more than double for a faster, bigger design, you would be talking of a saving of, conservatively, $200-250.

In its first quarter (Q4, 2010), Apple were estimated to have shipped more than 1 million MacBook Airs. Moving to ARM could have earned them a cool $250 million more profit in that quarter alone. That’s a billion a year just on the Air! In Q1, 2011, they shipped nearly 3 million laptops.

Should you trust a rumour from SemiAccurate?

Rumours are just that: rumours. Some do come true, some may been supposed to come true but later the story changed and some were always plain wrong.

Charlie has a pretty good hit rate with his: at The Inquirer, he dug down into problems with nVidia’s laptop GPUs to find the evidence that, despite nVidia’s denial, new lead-free solder bumps were too rigid and were failing because of the high number of repeated thermal cycles in a mobile device.

He drew attention to the damage to the relationship between Apple and nVidia caused by this and how Apple’s response was to replace them across their range. Well, sure enough, that appears to be happening: the only Apple products using nVidia products are now the Mac Mini, plastic MacBook and MacBook Air, all of which currently use a Core 2 Duo CPU that is is firmly on its way out in the next refresh of these lines.

However, he also predicted (as did others) that iPad 2 would have a Mini DisplayPort, which proved incorrect, even though it seems likely in the long run to feature on future iOS devices in the form of ThunderBolt.

Apple’s secrecy wall is tough to crack, for very good reasons, so the sources may or may not be accurate but, even if just a piece of sensible hypothesis, this is right up there.

Regardless of whether it happens by 2013 or not, this is clearly a massive opportunity for Apple and is fully in line with their overall strategy. Anybody want to bet that it will never happen?

As often happens, the question is not simple enough to answer in a 1 minute conversation, let alone a 140 character tweet. So this seemed like a good opportunity to try out our new blog and post an answer.

Clearly, on paper, a dual core 1GHz processor is twice as fast as a single core 1GHz processor. Add in the fact that it can do things in parallel means that it should be a mind-blowing experience. Or should it?

To those well-versed in the way that desktop computers have developed over the past decade will have already been through this transition once and be well aware of Amdahl’s Law.

As we’re used to an executive world, we’ll give you a TL;DR version.

SUMMARY: the phone should feel a bit smoother but you won’t have your mind boggled. Well-written apps could be around 50 to 80% faster and should be much smoother.

Good apps, like the web browser and maps application, will benefit greatly but many 3rd party apps are written with time-to-market on the mind, rather than optimisation, so won’t get a massive boost.

DEEP DIVE

First thing: our friend was worrying for no reason: Android is able to take good advantage of the second core straightaway; you don’t need to wait for a later version. It may not take full advantage and future Android versions will likely feature more optimisations in this area, but it’s a properly SMP-aware operating system, unlike Windows Mobile 6.x which only supported one applications processor core.

SMOOTHNESS

It’s somewhat harder to notice the absence of a problem than the presence of something amazing but, in a nutshell, that’s the main advantage of multi-core (SMP) systems.

The main difference is that the phone shouldn’t stutter as much as a single core phone – if there’s something happening in the background, then it can shove that onto one core and not have to disturb what you were doing. Basically, the phone should feel snappier and more responsive – that twitter app you left running won’t slow down Angry Birds as much.

It should be added, though, that this does depend on key areas of the operating system being written to take advantage of multi-core and, even then, there can still be some operations that lock even well-optimised apps out for a period of time, but it does remain an advantage.

BIG GAINS

The real big question is whether apps will get any larger meaningful benefit from the second core. If they’ve been written well, they should, but I wouldn’t assume that (given that most Android apps have had very little effort put into them).

What you must start with, as a developer, is to write “multi-threaded” code – this is where you split the job you’re trying to do into tasks that could be done at the same time instead of in sequence (parallel vs serial).

If your app is formed from just a single “thread” running everything in sequence, then you barely get any benefit from the second core: one will sit there maxed out and the other will be doing nothing. We’ve had multi-core on the desktop for nearly a decade and, still, many apps follow this pattern.

Some things are pretty easy to split into different threads like this: in a game you could have one “thread” for the sound, one for artificial intelligence (maybe even one per enemy), one for user interface and one for graphics. Android could decide what to put on each core, depending on which is least busy.

The downside is that it’s harder to code this way – you can end up with strange timing bugs which are hard to resolve… with such a low effort / reward ratio for most apps, you can bet they won’t be properly optimised.

WHAT DOES THIS MEAN?

So, while handset and tablet manufacturers may enthusiastically claim it’s “2x faster!!”, it would be very rare for an app to get anywhere near a 2x speedup from dual core because of those difficulties and other constraints/bottlenecks on performance (the graphics, the memory, the network, the bus, etc).

Another quick thing to point out is that it’s very rare that a mobile phone is that limited mostly by CPU speed… you spend loads of time waiting for the network. Showing complex web pages is one situation that does still tax the processor but Webkit is well-written to use dual cores so that should speed up nicely.

SO?!

Ultimtely, it’s a nice step forward but not a massive game changer. So why is such a big deal being made of it? Why go dual core in the first place?!

Well, when you develop a new processor, you have a few choices. Go parallel or improve your serial pace. For years, the challenge was to improve the serial speed. Get the MHz up, do more with one ‘tick’ of the clock. Then we really went for more ILP (Instruction Level Parallelism) with technologies like Intel’s SSX. What these did was to take one instruction and apply it to a whole load of data with one command – for example, “make all these pixels brighter”.

But this technique ran into a wall. Trying to make one single processor do more made the cores massive, power-hungry and inefficient. Enter the Pentium 4 – the last gasp effort at the single core monster. This chip was intended to ramp up to 10GHz, at which point, some parts of the chip doing simpler calculations would be reaching 20GHz.

Yet the Pentium 4 never officially exceeded 3.8GHz. This aproach just fundamentally took too much power.

The reason mobile chip manufacturers are no longer able to stick to the speed demon approach is that it’s got to the point where it’s miles more power-efficient to build two medium-fast cores than one really fast one. This is an approach called TLP: Thread Level Paralellism.

Power vs speed has an non-linear relationship: to double the performance of a single core chip will often take much more than twice the power. While the limits hit the Pentium 4 at less than 200W, the power limit for mobile cores is around 0.5W.

Likewise, to make a single core that is twice as fast as a 0.5W ARM core, with no manufacturing improvements, would take much more than 1W. So, what choice is left? Well, two cores, of course. At most, that should take 1W (actually, this would still really be too much for a handset design). When the CPU was the dominant component of a mobile chip, it would have been crazy to add a second CPU (not to mention pretty hard to build) but now that is not the case as the CPU has become a relatively small component of today’s massive SoCs like the Apple A5. Doubling that space is no longer a massive problem.

CONCLUSIONS

So, having reached that point, we’re clearly going towards multi-core chips. Great. But you won’t notice a big difference in performance until, firstly, the apps are ready and, secondly, the operating systems are fully-on-board. And you will not really notice it as a step change, but another sensible stop on the route towards a better future.

At this point, you’re much more likely to be noticing the difference from the higher performance of the new generation of mobile GPUs, higher speed memory, dedicated image processing and vector graphics accelerators and the speedier Cortex-A9 core design itself.

Multi-core definitely is the way to go, but it will be accepted through users noticing the trend of gradual improvements, and hyping it as a massive step change that will blow users’ socks off may well backfire, leaving people scratching their heads about what the big deal was supposed to be.

Here, a group of people from the mobile industry will be posting our thoughts about the world of technology, sharing interesting news, creating analytics and deep diving into some of the technologies which are changing peoples’ lives.

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