Spec Analysis: iPhone 5

It's not about the spec, it's all about the experience - that's the message we came away with from this week's iPhone 5 reveal. Vague on actual detail about the core innards of its new mobile, Apple's emphasis was on a phone that's obviously bigger but at the same time thinner and lighter, twice as fast as its year-old predecessor, and engineered to a level of precision measured down to the micron. This was Apple doing what it does best: creating a desirable product that excites the mainstream while at the same time generating a state approaching mania among its hardcore fans. How else can we explain the cries and whoops of delight that accompanied the reveal of a new docking connector and sync cable?

Bearing in mind that the firm had little in the way of new information to impart that hadn't already been revealed weeks - if not months - previously by the rumour mill, Apple did remarkably well in its presentation. There's not actually much here we didn't know already. The biggest change to the form factor is the height of the new screen; iPhone's Retina display has been extended height-wise to accommodate a new widescreen display, with an 1136x640 resolution taking over from the previous 960x640 screen of the iPhone 4 and 4S. The intention here is to make it easy for users still to operate the phone in one hand, while at the same time making for easier web-browsing and the support of 16:9 media content. There is also talk of superior colour reproduction, and a closer adherence to the full sRGB colour gamut as we saw in the new iPad.

The company's focus was to ensure that its customer base knew that the larger screen wouldn't make for an unwieldy phone, as is sometimes the case with the more outsize Android offerings, hence Apple.com's outsize factoids hammering home that the new phone is 18 per cent thinner, 20 per cent lighter and 12 per cent smaller in terms of volume compared to the 4S. Elsewhere, the focus was on delivering an even more refined user-experience: WiFi gets a speedier upgrade, the 4G LTE functionality added to the "new iPad" gets ported over, and the general business of navigating iOS certainly seems to be significantly improved. But in terms of the actual technological improvements within that precision-quality casing, Apple gave away less information than it ever has before - an intriguing move bearing in mind that the firm had it all to prove at this presentation after a less than stellar response to last year's 4S.

A few weeks back, we wondered where the Cupertino giant would take the iPhone technology in this new revision. In previous years, the solution has been extremely straightforward: port across that year's iPad processor lock, stock and barrel and downclock it by 20 per cent in order to retain decent battery life. However, with this year's A5X, Apple's options were limited: simply in terms of die-size, the new iPad chip is enormous and its entire purpose in being is to service the mammoth 2048x1536 resolution of the tablet's new Retina display. Fabricated at 45nm, A5X is also somewhat power-hungry, in part explaining a battery pack that offers capacity significantly in excess of the MacBook Air's. Only a shrink down to 32nm - a process Apple had already carried out with the A5 in iPad 2 - in combination with the usual downclock could make A5X suitable for a mobile phone. Even then, would a 2x GPU boost alone be enough to sell a premium phone to an audience expecting a vastly revised product after the iterative 4S?

"For a company with so much to prove with iPhone 5, the lack of emphasis on spec was surprising, with supporting metrics for the 2x performance boost a touch unconvincing."

The other opportunity Apple could have explored was to wholeheartedly embrace the fundamental changes to mobile processing tech set to arrive imminently in ARM's new Cortex A15 processor and the reputedly ultra-powerful PowerVR "Rogue" chipset - said by industry insiders to offer more GPU power than the Xenos chip inside Xbox 360, bolstered with DirectX 11-level features unavailable to the current-gen consoles. The technology is there, but the manufacturing processes to make it in bulk are not - it's for this exact same reason that the next-gen Xbox and PlayStation arrive next year and not this. However, if there is a company that has the resources and cash to make that happen sooner rather than later, it's going to be Apple.

In the event, true to form, Apple has found its own "third way" - almost certainly a hybrid of these two approaches. At this point, it's worth pointing out that the technological make-up of the new A6 processor remains unknown. Curiously, Apple itself is not interested in discussing specs other than to tell us that the new device offers "up to 2x" the performance of the existing iPhone 4S, and that it is capable of "console quality games" - and one or both of these statements may not stand up to scrutiny once the device is thoroughly benchmarked.

However, this information in itself is enough to rule out an early debut for PowerVR Rogue on the GPU side: a 2x performance boost simply doesn't do justice to IMG's achievement with its next-gen chipset, if our sources are to be believed. However, scaling up from a PowerVR SGX543 MP2 as found in the 4S's A5 chip to an A5X-style SGX543 MP4 would be entirely in keeping with Apple's known practices.

When it comes to doubling performance on a graphics part, there are two routes available: up the clock speed and take the hit to battery power, or double the amount of processors and produce larger, more expensive chips. Bearing in mind Apple's history in lavishing silicon on its mobile hardware, a move up to the new iPad's level of GPU power seems like the easiest and most likely route to achieving the 2x performance boost mooted by the marketing.

It's in the improved CPU performance that questions remain. Once again, there's nothing to stop Apple simply using the same dual-core Cortex A9s employed in the A5 and A5X and simply bumping up the clock speed. It's believed that Apple has employed the use of Samsung's 32nm fabrication process in the iPhone 5, as it did in its test outing in the revised version of the iPad 2 (which handed in substantial extra battery life as a result) - but quite how much extra thermal headroom that gives the engineers for increasing clock speeds is unknown. Alternatively, core count could be doubled, as we see with Tegra 3 and the PlayStation Vita processor. The other theory being mooted by analysts is that Apple has brought forward one part of the "next-gen" equation by switching to ARM Cortex A15 processors - or a hybrid variation, as seen in the Snapdragon S4 processor - which offer significant power efficiency and performance boosts over the existing A9s.

"Real Racing 3 was more a demonstration of the ever closing gap between mobile and current-gen console as opposed to any kind of revolution in smartphone gaming performance."

Short of a more direct heads-up from the firm itself, which way Apple has gone with its processor tech is going to remain unknown until devices are out in the wild and the A6 itself decapped and scrutinised under immensely powerful microscopes. What is clear is that commentators who've been hands-on with iPhone 5 are sufficiently enamoured with the increase in responsiveness, with traditionally sluggish apps proving to be significantly smoother.

However, actual metrics from Apple to back up the 2x performance boost claim proved to be few and far between: discussion of various app launching speed improvements, image saving from iPhoto and attachment viewing all looked good at between 1.7x to 2.1x better than the same task being performed on the iPhone 4S, but how much of this is down to faster flash memory, faster and/or larger system RAM or the dual-channel memory bus first introduced in the new iPad? These are somewhat bizarre metrics to flourish in discussing CPU or GPU improvements, leaving the door open to the possibility that the A6 may well have much more in common with the A5X on an architectural level than perhaps we are being led to believe.

Similarly, claims of "console quality" gaming are obviously somewhat subjective: Real Racing 3 is an obvious improvement over its low-poly, effects-lite predecessor, but it's clearly some way off Forza Motorsport or Gran Turismo. By Apple's own metrics (2x iPhone 4S), the A6's processing power is approximately on par with PlayStation Vita, the difference being that Sony's fixed architecture and focused development environment allows game-makers to code directly to the strengths of the hardware - a state of affairs that even mobile evangelist John Carmack acknowledged as a key advantage for the latest handheld PlayStation. Based on what was shown at the iPhone 5 reveal, Real Racing 3 is an interesting example of the gap closing a touch between console and mobile, but it is an iterative increase in graphical fidelity as opposed to the "photo-realistic" presentation it was described as by some. Once PowerVR Rogue is out there, and mobile becomes a viable target for current-gen AAA development, that should become fairly clear.

If there is some doubt about the claims surrounding the performance upgrade inherent to the A6, some of that may well be down to the statements surrounding battery life. Doubling power while at the same time increasing battery stamina is a claim sure to raise eyebrows, especially when Apple has also increased the spec of the power-sapping display, and increased resolution by over 18 per cent to boot. Only a thorough hands-on test can confirm whether Apple has made good on its marketing - something we hope to carry out as soon as the phone is released next week.

In the meantime, spare a though for the forgotten announcement at this week's keynote - the reveal of a brand new iPod Touch. Featuring the enlarged Retina display of the iPhone 5 and the same A5 chip found in the 4S, it's an intriguing mixture of old and new tech that should still provide an excellent experience. Although somewhat expensive at £249/$299 in a world where Nexus 7 costs £159/$199, the base 32GB storage is a step in the right direction, and in games applications it should still handily outperform the Tegra 3 tablets - and with the media playback power and the browsing real estate of the iPhone 5 at a much lower price, it deserves to do well. iPad mini? With the reveal of this handy little gadget, we'll believe it when we see it.