CPU Performance

For our cross-platform CPU performance tests we turn to the usual collection of Javascript and HTML5 based browser tests. Most of our comparison targets here are smartphones with two exceptions: Intel's Bay Trail FFRD and Qualcomm's MSM8974 Snapdragon 800 MDP/T. Both of those platforms are test tablets, leveraging higher TDP silicon in a tablet form factor. The gap between the TDP of Apple's A7 and those two SoCs isn't huge, but there is a gap. I only include those platforms as a reference point. As you're about to see, the work that Apple has put into the A7 makes the iPhone 5s performance competitive with both. In many cases the A7 delivers better performance than one or both of them. A truly competitive A7 here also gives an early indication of the baseline to expect from the next-generation iPad.

We start with SunSpider's latest iteration, measuring the performance of the browser's js engine as well as the underlying hardware. It's possible to get good performance gains by exploiting advantages in both hardware and software here. As of late SunSpider has turned into a bit of a serious optimization target for all browser and hardware vendors, but it can be a good measure of an improving memory subsystem assuming the software doesn't get in the way of the hardware.

SunSpider Javascript Benchmark 1.0 - Stock Browser

Bay Trail's performance crown lasted all of a week, and even less than that if you count when we actually ran this benchmark.  The dual-core A7 is now the fastest SoC we've tested under SunSpider, even outpacing Qualcomm's Snapdragon 800 and ARM's Cortex A15. Apple doesn't quite hit the 2x increase in CPU performance here, but it's very close at a 75% perf increase compared to the iPhone 5. Update: Intel responded with a Bay Trail run under IE11, which comes in at 329.6 ms.

Next up is Kraken, a heavier js benchmark designed to stress more forward looking algorithms. Once again we run the risk of the benchmark becoming an optimization target, but in the case of Kraken I haven't seen too much attention paid to it. I hope it continues to fly under the radar as I've liked it as a benchmark thus far.

Mozilla Kraken Benchmark - 1.1

The A7 falls second only to Intel's Atom Z3770. Although I haven't yet published these results, the 5s performs very similarly to an Atom Z3740 - a more modestly clocked Bay Trail SKU from Intel. Given the relatively low CPU frequency I'm not at all surprised that the A7 can't compete with the fastest Bay Trail but instead is better matched for a middle of the road SKU. Either way, A7's performance here is downright amazing. Once again there's a performance advantage over Snapdragon 800 and Cortex A15, both running at much higher peak frequencies (and likely higher power levels too, although that's speculation until we can tear down an S800 platform and a 5s to compare).

Compared to the iPhone 5, the 5s shows up at over 2.3x the speed of last year's flagship.

Next up is Google's Octane benchmark, yet another js test but this time really used as a design target for Google's own V8 js engine. Devices that can run Chrome tend to do the best here, potentially putting the 5s at a disadvantage.

Google Octane Benchmark v1

Bay Trail takes the lead here once again, but again I expect the Z3740 to be a closer match for the A7 in the 5s at least (it remains to be seen how high the iPad 5 version of Cyclone will be clocked). The performance advantage over the iPhone 5 is a staggering 92%, and obviously there are big gains over all of the competing ARM based CPU architectures. Apple is benefitting slightly from Mobile Safari being a 64-bit binary, however I don't know if it's actually getting any benefit other than access to increased register space.

Our final browser test is arguably the most interesting. Rather than focusing on js code snippets, Browsermark 2.0 attempts to be a more holistic browser benchmark. The result is much less peaky performance and a better view at the sort of moderate gains you'd see in actual usage.

Browsermark 2.0

There's a fair amount of clustering around 2500 with very little differentiation between a lot of the devices. The unique standouts are the Snapdragon 800 based G2 from LG, and of course the iPhone 5s. Here we see the most modest example of the A7's performance superiority at roughly 25% better than the iPhone 5. Not to understate the performance of the iPhone 5s, but depending on workload you'll see a wide range of performance improvements.

The Move to 64-bit iPhone Generational Performance & iPhone 5s vs. Bay Trail


View All Comments

  • Abhip30 - Tuesday, September 24, 2013 - link

    It's not cortex arm-a57. Since A6 apple uses arm achitecture. A6 was based on armv7 and A7 is custom design armv8. Reply
  • systemsonchip4 - Friday, September 20, 2013 - link

    First consumer device to have ARM A57 processor Reply
  • tipoo - Friday, September 20, 2013 - link

    It's a custom core, not A57 or anything else from standard ARM designs. Reply
  • systemsonchip4 - Saturday, September 21, 2013 - link

    Its a ARMv8 implementation, so yes it may be a little different then a cortex a57 SoC but it is still a ARMv8 Soc and that is why the A7 is able to beat the s800 SoC clocked at 2.3 ghz Reply
  • stevesous - Friday, September 20, 2013 - link

    Every year, they say we will see that in next year's model,
    When will you guys finally get it?
  • yhselp - Saturday, September 21, 2013 - link

    "Interestingly enough, I never really got any scratches on the back of my 5 - it’s the chamfers that took the biggest beating."

    "If you're considering one of these cases you might want to opt for a darker color as the edges of my case started to wear from constantly pulling the phone out of my pockets"

  • darkich - Sunday, September 22, 2013 - link

    Alright, I'll make a bottom line of this review.. I accused Anand of being Apple biased, now I take that back.
    He is simply and clearly an INTEL fanboy, even while believing in his utmost objectivity.
    He just can't help it.
    Then again, when you think of the decades of omnopotent Intel influence he was growing up with, in a way, that bias becomes only natural and forgiving.

    This is my message to you, Anand - Apple A7X will open your eyes real soon.
    Even you won't be able to overlook the ridiculous magnitude of superiority of that SoC to your Bay Trail.
    Mark these words.

    Take care, Darko
  • yhselp - Monday, September 23, 2013 - link

    It's not a matter of whether the A7/A7X is faster than a given Bay Trail variant, or at all. The fact of the matter is that Intel is sitting on some truly spectacular architectural IP and that's a scientific fact; the thing is that they can't seem to get it out in time. Bay Trail is but a 'baby', exceptionally conservative architecture whereas A7 or 'Cyclone' is not -- above all else it's wider.

    Apple/ARM is better or as-good this round and might continues to be in the future if Intel doesn't speed up it's game. That's true. However, even Intel's smaller architectures ARE superior to A7/ARM, let alone their big Core stuff (which isn't far from being synthesized for smartphone use); not to mention their manufacturing process advantage.
  • talg - Sunday, September 22, 2013 - link

    Do you know from SoC point of view what function does A7 have ? Reply
  • justacousin - Sunday, September 22, 2013 - link

    Based on some of my reading Samsung is the manufacturer of the A7 chip, what is to be said about this? Reply

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