iPhone 5s full review - Page 3


We continue our iPhone 5s review with a look at the specifications and iPhone 5s performance.

iPhone 5s review: The A7 processor

Apple has turned its hand to processor design for several generations of iPhone chips now, starting with the Apple A4 chip that premiered in the iPhone 4. Some people will point to the fact that Samsung currently manufacturers the chips, but all that company does is construct them to Apple's pattern. In recent years Apple has invested in chip building expertise, acquiring no less than three chipmakers: Passif Semiconductor, Intrinsity and PA Semi. Apple is also said to be looking away from Samsung for the fabrication of the chips – most likely to avoid a situation where Samsung might be able to steal Apple's secrets. And secrets worth stealing Apple has.

The iPhone 5s, along with the iPad Air and new iPad mini all share Apple's A7 chip. The A7 processor runs at 1.3GHz, it's a dual-core processor paired with 1GB of RAM. While Apple has revealed little about the chip, iFixIt has taken the iPhone apart and can confirm that, like its predecessors, the A7 is based on the ARMv8 architecture.

A7 processor  

Those numbers might not sound as impressive as some of the processors offered by competing smartphones, for example, the Samsung Galaxy S5 offers a 2.5GHz quad core processor with 2GB RAM, while the HTC One M8 offers a 2.3GHz quad core processor and 2GB RAM. However, there are various reasons why the speed of the processor and the amount of RAM doesn't necessarily add up to a better phone, not least the fact that your smartphone's performance boils down to more than the number of cores it has.

Here are a few: A quad-core processor is faster than a single- or dual-core processor only when it's running an application that's been developed to take advantage of its abilities (usually iPhone games) so this extra processing power is going unused; it's better to use a chip that's been designed to use less power as that preserves battery life; speaking of which, extra RAM will also draw more power and shortens battery life; finally and most crucially, Apple's iOS doesn't need a faster processor or more RAM to run smoothly. We sometimes suspect that the race to faster processors and more RAM is a marketing game, just like the unnecessary increases in megapixels you see in competing smartphones.

So, despite the fact that some may consider that processor speed of the A7 chip is slower than the competition, this latest design is undoubtedly a major advance in processor engineering.

The move to 64-bit sets Apple – and iPhone 5s users – up for the future. Among other things, 64-bit processors can address 4GB of memory, which will help with processor heavy apps like Photoshop, and perhaps enable the iPhone to play 4K video. It should also be able to handle higher-end hardware, such as high-definition screens, and should allow the iPhone 5s to make light work of running multiple tasks concurrently. However, the iPhone 5s has only 1GB RAM so it won't be able to take advantage of this greater memory addressability.

Apple was the first to bring 64-bit desktop-class architecture to a smartphone. For another indication of how important it is, note that, following the announcement, Samsung was quick to claim that it's developing devices with 64-bit chips, too. Although it's still not launched a 64-bit product months later…

Getting inside the iPhone 5s

64-bit accomplishments aside, Apple claimed the new chip would provide twice the CPU and graphics performance of its predecessor while still delivering long battery life. Apple said it has: "Engineered iOS 7 and all the built-in apps to maximize the performance of the A7 chip."

The real boon for Apple's new A7 chip and its architecture is what it will do in other, future Apple devices. Even while it matters little to this phone here and right now, followers of computing technology will recognise this as a significant advance which heralds some interesting developments, and sooner rather than later.

At launch Apple boasted an "up to 2x" speed increases when measured against the already fast Apple A6 found in the iPhone 5. However, nobody was complaining that the iPhone 5 is slow – indeed, the iPhone 5 remains plenty fast, at least for now. While competing Google Android phones suffer perceptible lag issues in the interface, making users chase the rainbow of faster phones, the latest iOS 7 runs relatively slick and smooth on recent iPhones.

Here's a list of some of the iOS Apps that make use of the A7 chip and some of the best iPhone 5s games that use the A7 chip.

iPhone 5s review: iPhone 5s benchmarks

We advise that anyone looking for a new smartphone takes any benchmarking results with a liberal pinch of salt. Benchmark testing of a phone's performance became entirely moot when Samsung and Google's other hardware partners were caught cheating by fiddling with the processor when benchmark apps were running. Until these phone manufacturers were found cheating the system these benchmarks were used to judge progress in chip design between phones. Now we have no meaningful numbers to compare - at least not against Android-based phones. Research from AnandTech confirms that at least Apple is not using these dirty tricks to artificially inflate its numbers so when comparing Apple phones you will get a realistic illustration of processor accomplishments.

With all that in mind, let's look at some numbers from Geekbench.

Version 2 of the popular benchmark application rated our iPhone 5 with around 1660 points. The same app puts the iPhone 5s at an average of around 2240 points - so that's about a 35 percent increase in point score at least.

Version 3 of Geekbench includes separate single- and multi-core processor measurements. We saw 724 points from the iPhone 5 in single mode, and 1409 points for the 5s - nearly double, actually a 95 percent increase.

In the Geekbench 3 multi-core test, the point scores rose from 1298 to 2556, similarly almost two-fold; a 97 percent score boost.

In the GFXBench 2.7 test, running EgyptHD, the iPhone 5s averaged 53 frames per second, which is pretty nippy. In practice any game or graphic-intensive task on the phone should look exceptionally fluid.

To give a rough idea of browsing performance, the SunSpider test will explore the speed of JavaScript rendering. That's not the same as web-browsing speed per se, although since so many web developers rely on JavaScript to make their sites dynamic and interactive, the test gives some guide of loading and rendering performance. The iPhone 5s completed the task in 417 millisecond, which back in October 2013 was fastest figure we've seen for any smartphone or tablet on any platform – and still is, for example, the HTC One M8 achieved a result of 640ms in the same test.

Following these tests we are able to say that the iPhone 5s is twice as fast as the iPhone 5c and the iPhone 5. Upgraders from the iPhone 4s will be even more impressed, as the iPhone 5s is about six times faster that that phone.

Such benchmark numbers are really only kicking the tyres, though: what really matters is how the phone feels, particularly now benchmark tests' usefulness have been invalidated by desperate Android pedlars.

In use we found the iPhone 5s to be slick and responsive, if not as quick in screen animations as an iPhone 5 running iOS 6 (but this is a result of the new interface changes in iOS rather than a criticism of the iPhone itself). While most of the time the whooshing perspective effect of opening and closing an app appeared seamless, at other times we could see some of the intermediate frames of the animation in a more stilted way.

We have experienced some app crashes – Safari and Settings to name but two – the phone recovered instantly and seamlessly each time with barely any delay as it re-launched them. We suspect that some of these issues are due to memory management; we often find the phone slows down as the 1GB of RAM reaches its capacity. During the months that we have been using the phone the various updates to iOS 7 have improved this.

When the iPhone 5s launched in September 2013 very few iOS apps had been tuned to that device. A number of Apple's apps utilize this 64-bit processor and over the months that followed the launch more developers have begun to channel the extra processing power of the iPhone 5s into their apps, for example, Infinity Blade III, Sky Gamblers, 123D Creature and SketchBook Mobile (both from Autodesk), and djay 2. If you want to gage the difference the processor makes to apps look to the Camera app, which gains extra features on the iPhone 5s compared to other iPhones.

Infinity Blade

iPhone 5s review: the M7 chip

In addition to the A7 chip, the iPhone 5S has a brand new part called the M7. This motion compressor takes advantage of all of the sensors in the iPhone – accelerometer, gyroscope and compass – and continuously measures the data coming from them. It does all this without having to wake up the A7 processor, which is good news for battery life.

Thus the key function of the M7 is to process the large amounts of data people can generate while carrying a sensor-laden device (and perhaps, one day, an Apple iWatch). Triangulating this data takes processing power, but not a huge amount of it. By offloading these basic processors to a secondary chip, Apple is able to improve power efficiency in the iPhone 5s. As a result you see two big advantages: increased battery life and a reduction in the heat generated by the main processor. By preventing the iPhone 5s from getting hot Apple may even have achieved a longer lifespan for the device.

What's inside iPhone 5s

The second advantage of the M7 is that it boosts the performance of the main A7 processor. The supplementary chip frees up the A7 processor so that processing cycles are available for other jobs.

Apple hasn't publicly detailed just how the M7 works, though it has added a new set of APIs, dubbed CoreMotion, which developers can access when writing iOS 7 apps. At launch Apple pitched the M7 as an advantage for fitness and activity-tracking apps, saying that, thanks to the M7, the iPhone 5s "continuously measures your motion data, even when the device is asleep, and saves battery life for pedometer or other fitness apps that use the accelerometer all day." Since launch a number of app developers have begun tapping this chip, for example a number of pedometer apps that use the M7 to measure daily steps, and Fitbit is using the M7 for its MobileTrack feature in its personal activity tracker app.

The M7 is a pretty convincing indicator that Apple is working on the rumoured iWatch, with reports suggesting that Apple will include health-monitoring sensors in that device.

When Apple launched the iPhone 5s with the motion coprocessor it was the first time such a processor had appeared in a phone. Now, months later HTC has adopted similar technology in the One M8, which is used for its Motion Launch Gestures and to track activity via its pre-loaded Fitbit app.

The M7 could be used by iWatch

Turn to page 4 of our iPhone 5s review to find out more about the iPhone 5s specs >>

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