The first SunSpider and BrowserMark benchmarks 9to5Mac told you about yesterday confirmed the iPhone 4S as being “twice as fast”, per Apple’s tagline. Today, AnandTech published a more thorough analysis based on Javascript, CPU and GPU benchmarks of Apple’s latest handset. Thanks to the dual-core A5 chip first outed with iPad 2 this Spring, Javascript performance on iPhone 4S “finally catches up to Tegra 2 based Honeycomb devices, while general CPU performance is significantly higher than the iPhone 4″ – about 68 percent, to be precise.

More importantly, Geekbench results (seen below) tell us that iPad 2 is clocked around “25 percent higher than the iPhone 4S”. Overall, the Apple-designed dual-core A5 chip inside iPhone 4S is estimated to run at 800MHz versus iPad 2′s 1GHz A5 processor. This isn’t entirely unexpected due to the battery concerns and the handset’s much smaller 5.25 Whr battery. Furthermore, Apple says iPhone 4S has “up to seven times faster graphics” versus the advertised “nine times faster graphics” on the iPad 2 – another proof that the two device’s graphics processing units are not clocked equally.

As we predicted, Imagination Technologies’ PowerVR SGX543 graphics units ticking inside the iPhone 4S is also significantly speedier compared to the ARM-based Mali-400 GPU found in the Samsung-designed 1.2GHz Exynos 4210 processor (they recently announced the improved 4212 chip) used in the Galaxy S II smartphone. By all accounts, the iPhone 4S has the fastest graphics in a smartphone yet. Anand Lal Shimpi and Brian Klug explain:


Chart courtesy of AnandTech

A lower clock not only means higher yields from the factory, but likely a lower operating voltage as well. Dropping a CPU’s core voltage, yields a greater-than-linear decrease in power consumption, making the marginal loss in clock speed a good choice. At a lower operating frequency than its Android competitors, Apple does have to exploit its strengths in software to avoid any tangible performance penalties. Apple has traditionally done this very well in the past, so I don’t expect the loss of frequency to be a huge deal to the few who do cross-shop iOS and Android.

GLBenchmark 2.1 (see results at the bottom of the article) paints the iPad 2 as having a 21 percent performance advantage over the iPhone 4S, stemming from different clock speeds. All said, both iPad 2 and iPhone 4S are well-equipped devices and are more than capable to run the latest games and graphics-intensive applications “at well north of 30 frames per second”. Summing up, game developers will likely optimize graphics in their titles for the iPhone 4S rather than for the iPad 2 in order to avoid the undesired performance penalties on the iPhone 4S. The Apple-designed, Samsung-manufactured A5 chip is thought to pack in a dual-core Cortex-A9 processing core from ARM Holdings, Imagination Technologies’ PowerVR SGX543 MP2 graphics unit (also dual-core) and debatable 1GB of RAM. Granted, those specs are not official as Apple doesn’t divulge chip details and its partners are equally tight-lipped on the matter, so the expected x-ray analysis should shed more light on the iPhone 4S processor’s innards.


Chart courtesy of AnandTech

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