Mobile performance – a look back

How fast are mobile CPUs these days? Well, they are pretty fast processors.

While some still consider that x86 is ten times faster than ARM, that is just not the case anymore these days, the difference is much smaller, and closer to just two times if you compare a regular smartphone to a regular laptop/desktop.

CPU JavaScript Performance x86 vs ARM

The difference between the ARM-powered low-cost Samsung Chromebook and the high-end x86-powered Chromebook Pixel is usually around or less than two times:

Benchmark ARM Samsung 550 Chromebook x86 Pixel Chromebook How much faster?
SunSpider 776 480 1.6
Octane 5585 11846 2.1
Peacekeeper 2142 3753 1.7
Kraken 2265 4962 2.2
RoboHornet 80.6 120.7 1.5

Those were JavaScript benchmarks, but this was pitting a Core i3 processor. What about Atom, the low-power x86 offering? Anandtech looked at it in their December 2012 x86 Atom review.

If you want x86 to pull further ahead, you need to use the power-hungry Core i7, but the performance ratio still will not be ten times. On the other hand, the power consumption ratio might be closer to 100 times: a high-end Core i7 has a TDP up to 130W and really needs it, while the quad-core Krait draws around 1-2 W under load for a 4W TDP.

CPU floating-point performance

pi-blackI picked another computing benchmark, SuperPI. This is a single-threaded benchmark, but it has historical results available from long ago. I’ve summarized a few scores:

  • Modern Core i7/i5 at full power : around 7-10 seconds
  • Nexus 4 (ARM, Krait) : 17 seconds
  • 3 years ago, (AMD Phenom II) : 21 seconds
  • 10 years ago, Pentium 4 @ 2.4 GHz : around 50 seconds
  • 15 years ago, Pentium II @ 266 MHz : around 450 seconds

Also keep in mind that quad-core is commonplace these days, five years ago, dual-core was the standard, ten years ago, it was single core everywhere but in very expensive servers. So there is an extra 4x ratio between old CPUs and modern ones.

Next: CPU and GPU in perspective.

11 thoughts on “Mobile performance – a look back

  1. A performance ratio of about double the speed sounds reasonable.

    It’s dependent on the ATOM processor kind. You will have distinguish between the Z series and the ATOM for mobiles. In the end the decision is about the energy consumption per work unit.

    ATOM Z series needs about 50 to 60% less power compared to a Cortex 9 but I have found no source if the energy consumption per work unit is considered.

    I could imagine that ARM requires less in general but I don’t know, maybe it’s the other way around. In general the ISA does no longer have a great impact if any on the speed in general.

    There is no almost no real speed-up because of the clock rate anymore. The environment is optimized. Faster hard-disks or none. Faster memory access… I think the only benchmark that does make sense is if you test on a device directly.

    The idea is that what is a Core 3 to 5 today will become the ATOM series … Mobile processor will become a Desktop processor, Desktop – Server …

  2. I am most curious about that SupePi test. So it comes down to smartphone computing power is roughly 50% that of one of best Intel’s CPUs. I do not want to challenge all these results but you are telling that for $600 I can have very powerful computer that takes up no space, consumes virtually no power and crunches numbers with the speed good for 90% of the users. It sounds highly suspicious. Why are not we seeing those tiny and powerful PC’s all over the places then?

    Now I can tell about my own experiment. A little while I’ve written short single threaded demo program in C to model some physical process. I ran it on my older 2.6GHz Corei7 (Windows 7) and on 1GHz embedded Intel compatible CPU on which I put 32 bit DOS so I can have unfettered access to resources.

    The end result was 50 times difference in speed. How do you explain that?

  3. The Nexus 4 is $300 actually. And you’re seeing those tiny computers all over the place actually, they’re the reason why the PC market sales are going down. On servers, they’re becoming very common as well in holsters and for entry-level cloud VMs.
    As for your test, maybe you should blog about it with more details? (What it was doing exactly, the hardware, etc.) If that 1 GHz intel compatible CPU was a VIA though, you’re looking at a Pentium 2 era performance, so that 50 ratio could be about right.

  4. It seems you didn’t benchmark *native* code, but the interpretation of javascript inside the browser ? And browsers can be very different from one platform to the other.

  5. Look again, there are several native benchmarks. Also the browser tests are between ARM & x86 versions of Chrome OS, not different browsers.

  6. Hello, interesting benchmarks!
    How is Kraken score computed? Tried it on a cheap i3 / Firefox 22 / Win8, and got
    2927.1ms +/- 9.3%
    so it seems that the lower the score, the faster the PC.
    On your table, the x86 ChromeBook has an higher score than the ARM one, but it is reported to be 2.2 times faster. Maybe the results have been switched?

  7. Did you factor the time ChromeOS spent sending all your data to Google? I’d perform this test with a different OS, for example installing a true Linux on both and then check the differences.

  8. I do like these kind of tests and benchmarks. But any one I had read don’t “feel right”.
    Seems we are comparing bananas to apples (pun intended?) .
    Price, market share, already users hardware base, are some of the others things that someone must compare accordingly to the objective of the post.
    Yes, yes, I know you are not saying one is better than another.

    Note: Link to “x86 is ten times faster than ARM” seems broke;

  9. The cpu speed of mobile devices is where desktops were yesterday, but the available software for them is about 10 to 15 years behind.

    15 years ago we already ran 3d studio, delphi, photoshop, visual studio, cubase and matlab on our average pc’s. Even wordperfect and office 97 were more advanced that anything that I’ve seen for mobile devices today.

    When you keep in mind that today’s mobile devices are so much faster that our pc’s were in 97, it’s saddening to see that all the extra cpu cycles are wasted on fart apps and other one-trick disposable apps.

  10. At home I have a 12 year old 933Mhz Pentium with W2k and Delphi 7. It is running faster and smoother than my Quad core high cost PC at work with XE4. Faster CPUs have no advantage with modern (crap) Software.

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