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Apple iPhone 4S, Part 1: More Horsepower, Better Hardware

More CPU Horsepower Equals Better Experience

The iPhone 4S delivers better performance because it centers on the A5 system-on-chip, whereas the 4G uses the A4. Incidentally, earlier this year, Apple transitioned to the A5 on its iPad 2. So, if this seems like familiar ground, it really is. We already covered the architectural differences between the A4 and A5 in our iPad 2 review (Apple's iPad 2 Review: Tom's Goes Down The Tablet Rabbit Hole). So, if you want a refresher, feel free to check that story out. Today, our discussion is limited to performance.

AppleiPadiPhone 4iPad 2iPhone 4S
SoCA4A5
Processor1 GHz ARM Cortex-A8 (single-core)800 MHz ARM Cortex-A8 (single-core)1 GHz ARM Cortex-A9 (dual-core)800 MHz ARM Cortex-A9 (dual-core)
Memory256 MB LP-DDR (single-channel)512 MB LP-DDR (single-channel512 MB LP-DDR2 (dual-channel)
GraphicsPowerVR SGX535 (single-core)PowerVR SGX545MP2 (dual-core)
L1 Cache(Instruction/Data)32 KB / 32 KB32 KB / 32 KB
L2 Cache640 KB1 MB

Performance between the iPad 2 and iPhone 4S is not comparable though, because Apple underclocks the iPhone's A5 down from 1 GHz to 800 MHz. According to GeekBench v2, the iPhone 4S delivers about 60% more performance than its predecessor, but, as we'd expect, still falls shy of the iPad 2.

Geekbench v2, Score in Points (Higher is Better)iPadiPhone 4iPad 2iPhone 4S
Overall456383746624
Integer365294681562
Floating-Point458367909737
Memory678616787707
Stream325286323284

As it relates to real-world performance, this speed-up will manifest as faster boot-up and more responsive application launch times.

In the past, we've used a 1000 FPS high-speed camera in order to quantify the input lag you experience from typing on a virtual keyboard. This tells you how fast a smartphone registers an action. Ideally, you want low input lag so that you don't feel like the phone is stuttering as you type or click buttons. At a minimum, we're looking for input lag below 200 ms because that reflects the average reaction time of a college student to visual cues (though some competitive gamers can react within a 100 ms window).

It's common for actions to take 120-140 ms to register on the iPhone 4, according to our high-speed camera test. But, thanks to the A5, Apple's iPhone 4S offers around 50% less input lag, in the range of 80-90 ms. That's a notable improvement, especially for the folks who consider themselves to be seasoned texters.

  • maddogjt
    On the CPU spec chart, iPhone 4S is mislabeled as iPad 2
    Reply
  • halcyon
    Its a nice phone.
    Reply
  • acku
    maddogjtOn the CPU spec chart, iPhone 4S is mislabeled as iPad 2
    Thanks for catching that. Fixed!

    Cheers,
    Andrew Ku
    TomsHardware.com
    Reply
  • dragonsqrrl
    ...that's what you'll get with an SGX543 MP2. Imagine the performance of the PS Vita with an MP4 and twice the Cortex9 cores.
    Reply
  • jimmysmitty
    My only question is why is it only being compared to competition in the form of tablets? Why is there no Droid Bionic or the Galaxy SII?

    Are we to think the iPhone 4s is equal to a tablet? Especially considering the Bionic has a faster dual core (1GHz Core), more RAM (1GB), Android 2.3.4 (Gingerbread) and is a phone, like the iPhone.

    Honestly this review is lacking since it doesn't compare actual phones from other companies (be it Android or WP7) and instead compares it to tablets.
    Reply
  • aznshinobi
    Why do people think the iPhone 4S is revolutionary or just amazing? The Galaxy S2 is thinner, has a better CPU, and has a much larger screen. To me the 4S is a huge rip-off. iOS5 has a few things they've stolen of Android that people think are "new".
    Reply
  • tramit
    aznshinobiWhy do people think the iPhone 4S is revolutionary or just amazing? The Galaxy S2 is thinner, has a better CPU, and has a much larger screen. To me the 4S is a huge rip-off. iOS5 has a few things they've stolen of Android that people think are "new".
    I don't know about you but I also think it is amazing that a year later any iPhone can hold its value much better then its competing Android counterpart. When I purchased my Nexus S it wasn't to bad, but a couple months later and a huge chunk of the value was lost. Whether you like it or not the iPhone can hold its value due to the large demand.

    The GSII some would say is not revolutionary as well compared to the GSI which is the same approach it seems that the iPhone took from the 4 to the 4S. Even though the GSII has amazing hardware, the software still crashes quite often. You would think that with all the power under the hood that it would work more smoothly but it does not. My Nexus S with the most up to date Android software is still buggy at the most annoying times. If I weren't with T-Mobile I would have probably gotten the 4S. Hopefully the Nexus Prime will come to T-Mobile as well and ICS will have fixed even more bugs and work on a seemless and fluid user experience without crashing or having to send an error report.
    Reply
  • acku
    9521240 said:
    My only question is why is it only being compared to competition in the form of tablets? Why is there no Droid Bionic or the Galaxy SII?

    Are we to think the iPhone 4s is equal to a tablet? Especially considering the Bionic has a faster dual core (1GHz Core), more RAM (1GB), Android 2.3.4 (Gingerbread) and is a phone, like the iPhone.

    Honestly this review is lacking since it doesn't compare actual phones from other companies (be it Android or WP7) and instead compares it to tablets.

    Agreed. Excellent point. We'll add other smartphone as reference points.

    Cheers,
    Andrew Ku
    TomsHardware.com
    Reply
  • AbdullahG
    aznshinobiWhy do people think the iPhone 4S is revolutionary or just amazing? The Galaxy S2 is thinner, has a better CPU, and has a much larger screen. To me the 4S is a huge rip-off. iOS5 has a few things they've stolen of Android that people think are "new".I have yet to find someone how thinks the 4S is revolutionary. Innovative, yes, but not revolutionary. And people think iOS5 has new features which Android had simply because people are more aware of the iPhone rather than Android phones. Living in NY, there are a lot of busy routes. One such route which is commonly used to get to Manhattan has a huge billboard advertising the iPhone. Remember, these routes are full of busy people getting to work and so on. The iPhone is going to look appealing to such people. Why? Because they make of majority of the market for smartphones.
    Reply
  • jimmysmitty
    9521243 said:
    Agreed. Excellent point. We'll add other smartphone as reference points.

    Cheers,
    Andrew Ku
    TomsHardware.com

    I just happen to have gone from a LG Ally to a Droid Bionic (holy crap major difference.

    I can give you my sores but I am a bit afraid they might be off since Verizon tend to load the most crap they can.

    Overall its not too bad, its got a PowerVR SGX 540.
    Reply