Battery Life

Performance isn’t the only benefit that comes with Tegra 4 – NVIDIA and Microsoft also enjoy a smaller/lower power process: TSMC’s 28nm HPL. Of course four high-clocked Cortex A15 cores drives max power consumption higher than on Tegra 3, but idle power consumption and power efficiency at lower clock speeds should be better. As with most present day mobile devices, the move from Surface to Surface 2 comes with an increase in dynamic range of power consumption. I put Surface 2 (as well as Surface RT) through our 2013 tablet/smartphone web browsing battery life test and came away with around 8 hours of use on a single charge. That’s definitely not the lowest power that we’ve seen, but it is an improvement over the 6.8 hours Surface RT managed in the same test.

Web Browsing Battery Life (WiFi)

As with all modern Tegra SoCs there’s one extra “companion” core designed to be used for lower power/performance operation. Unlike under Android, there’s no hot plugging of CPU cores under Windows RT – there are always four Cortex A15s presented to the OS/scheduler, regardless of whether or not the companion core is active. Microsoft tells me the companion core is used on Surface 2 (unlike its predecessor), however specifics are tough to come by. Microsoft claims the companion core is used during full screen video playback. The only thing I can think of is that the hardware migrates the companion core in under certain circumstances, taking the place of one of the four A15s, and software specifically sets processor affinity in this case. I tried confirming whether or not this was the case by playing a movie and inspecting the process under task manager, unfortunately I came up empty handed. The video playback process wasn’t set to run on any one core in particular, it was allowed to run on all four exposed cores.

Video Playback Battery Life (720p, 4Mbps HP H.264)

However it’s used, the impact seems to work relatively well. Surface 2 managed just over 10 hours of battery life in our video playback test. It’s not the best we’ve seen in this test, but it’s definitely competitive with other flagship devices.


Surface 2 ships with Windows RT 8.1, and similarly absorbs all of the improvements that 8.1 brought to x86 machines as well. A number of ARM specific optimizations are under the hood, which should help improve both performance and power consumption.

The biggest issue with Surface 2 remains on the software front. Developer support for Windows Store applications is no where near where I thought it would be by now. There are some big ones (Netflix, Facebook), but there’s still no good Twitter client, no amazing IM client, and of course you don’t get good integration of Google services anywhere (outside of leveraging Mail for Gmail access).

Without opening up classic desktop APIs to developers, we won’t see alternative web browsers like Chrome or Firefox on Windows RT 8.1 either. Although IE11 does a relatively good job on the touch front, I find that heavy multitasking with IE11 on Surface 2 can result in a lot of hangs and crashes within tabs or the application itself. I can understand Microsoft’s hesitation on this front (better control over the platform if you don’t open it up), but I can’t see a future where Windows RT is successful and Microsoft doesn’t allow developers to access both sides of the platform.

SoC, CPU & Performance Final Words


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  • Qwertilot - Monday, October 21, 2013 - link

    Closest competitor would be something like that Transformer book T100, which is seemingly 349 in its cheapest form, keyboard included. Yes S2 is nicer in a few ways so you could justify a relatively modest premium but nothing enormous.

    I don't actually think the iPad/this stuff are in direct competition. Optimised for fairly different sort of uses.
  • tipoo - Monday, October 21, 2013 - link

    Does typing cause such load with the touch cover, or type cover too? If it's just the touch, I wonder how much that impacts battery life? Seems like regular keyboard typing shouldn't produce that much load.

    Bummer that the Sunspider browser performance doesn't bear out anywhere else, I had hoped they pulled some crazy software wizadry to beat the A7 even with a slower SoC. Also makes me question how Intel showed off BT on IE11 to prove the A7 nearing it was just a matter of browsers, if IE11 just optimizes for sunspider. It still is a very fast browser though. I don't even mind using it, if not for lack of third party extensions.
  • Daniel Egger - Monday, October 21, 2013 - link

    Actually I suspect that most of the performance improvements are due to Windows RT 8.1 vs. 8.0 the original Surface RT was tested with. I've updated mine and it feels a lot faster (though it also has plenty of new bugs, especially in IE with flash videos). However I wonder why the article mentions the lack of speed of the Surface RT a couple of times but the bars in the graphs are missing. Also I'd like to suggest to retest the old RT with 8.0 and 8.1 and put those 2 extra bars in. Reply
  • domboy - Monday, October 21, 2013 - link

    "Without opening up classic desktop APIs to developers, we won’t see alternative web browsers like Chrome or Firefox on Windows RT 8.1 either.
    I can understand Microsoft’s hesitation on this front (better control over the platform if you don’t open it up), but I can’t see a future where Windows RT is successful and Microsoft doesn’t allow developers to access both sides of the platform."

    Thank you!! This is unfortunately the real problem with Windows RT. Lots of people have said this same thing in forums, but maybe Microsoft will actually listen when Anand Lal Shimpi says it. I love my Surface RT, but the lock on the desktop APIs is going to be the doom of this OS. Why bother with it (customer or developer) when Intel tablets are going to be the same price, the same battery life, and able to do so much more? The Surface RT/2 hardware is REALLY nice, but the OS is a sad tale... and the "jailbreak" for RT 8.0 just further proves this point.
  • isaacsou - Monday, October 21, 2013 - link

    Use also the metric system in the articles/reviews!!!
    The readers outside US doesnt know (and dont want to know) what a lib or inch means!
    Just put in parenthesis on the side
  • A5 - Monday, October 21, 2013 - link

    2.2 lb = 1 kg
    1 inch = 2.5 cm

    They're not hard conversions, and you should memorize them if you're going to read a lot of American websites.
  • MarcSP - Tuesday, October 22, 2013 - link is a pretty technical website that wants to be (is) international. It is only logical to use international units besides the local ones. I don't think that it would be a drawback for anyone. In what grounds would you oppose?

    Please Anandtech, do it! :-)
  • MarcSP - Tuesday, October 22, 2013 - link

    Even Engadget does it! (And they put international units first. See: Reply
  • azazel1024 - Monday, October 21, 2013 - link

    Yes, if this had a Baytrail in it, it would be a must buy for me.

    That said, the price would still be too high. $549 for 64GB PLUS having to spend money on the touch cover puts the price wayyyy too high. That is, what? around $670 for the thing plus touch cover?

    Nah ah.

    If the touch cover were included, and it had a z3770 in it and 3 or 4GB of memory (keeping in mind that Windows 8.1 32-bit is the only connected sleep supporting version of Windows right now) and the price was $549, then I'd probably buy it in a heart beat.

    Maybe I don't speak for most, but I feel like $500 is generally more or less the ceiling on what I'd ever consider spending on a tablet. Above that it is getting too close to ultrabook territory. Yes they are still vastly different devices, but looking at the Surface 2, tossing in another $200 and you can find many examples of very good 11.6-13 ultrabooks in that price range with very good hardware, screens, etc and vastly faster CPUs and GPUs in them.

    Tablets by and large are content consumption devices with some minor productivity work. A dock (T100) or type cover (Surface 2) help out with that minor productivity work a lot. However, at roughly $670 for the "kitted out" Surface 2, its too expensive to replace a low end 11.6" ultrabook (more expensive than a number of them) and it doesn't work as well for the productivity bit. If you mostly want it for content consumption...sure the screen is nice, but I don't think it beats out most of the $300-500 10" android tablets, nor does it beat out something like the T100 by much (in terms of being spiffy for content consumptioN)...and NOT by more than 50% extra cost.

    I think that is the issue that MS is going to continue having. Windows RT is just damned limited and the hardware is nice, but with the price and the limitations of RT it just isn't compelling.

    At $50 less with a free type cover included and it might be in the compelling zone for a lot of people, but it isn't.
  • azazel1024 - Monday, October 21, 2013 - link

    I can't speak to skydrive, as I haven't touched in since I upgraded to 8.1 yesterday. However, in upgrading I found two things.

    Yes, it requires a Microsoft account. Stupid, but it does. Once you upgrade, you can "downgrade" the microsoft connected account, to a local account again. Its under the metro settings for user accounts. Find the user account and if you poke around in the settings there is an option to change it to a local account. It gets pissy with you trying to do it, but it WILL let you do it.

    Next, Lucid Logix Virtu MVP does not work under Windows 8.1. Or at least it doesn't work with my AMD 5670 and i5-3570. 8.1 upgraded fine, but after initial boot it cratered after 60 seconds and then boot cycled everytime it finished loading and was about to bring up the start screen. I managed to boot to safe mode fine, on a lark I tried reinstalling Virtu MVP. I then booted as normal just fine. It finished installing Virtu MVP and then proceeded to flash the BSOD for about 200ms and then boot cycled again.

    Nothing I have tried (other than uninstalling it and running with either just the dGPU or iGPU) has worked.

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