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


View All Comments

  • Da W - Monday, October 21, 2013 - link

    1- I use both MS and Google services on my surface (pro) and android phone (and dropbox). I do prefer MS bundle overall. I find also that its a generation thing, most aged 30-40Y tend to prefer MS while the younger generation tend to hate MS (and choose Google).

    2- Every google services, facebook, twiter, most "apps" are accessible in their internet version via ie11 and pinable on the start screen. In fact i think the lack of apps on the Windows store is a non-issue. On my android phone, i use mostly apps and almost never use the chrome browser. On my surface it's the opposite, i use almost no apps and do everything i need in the browser. (working in the browser is also the point of google chrome, so it's not a bas thing).
    I think the # of app issue is overrated.

    3- Agreed you can put Windows RT in the same class as google chrome, functionnality wise. That is: a limited OS that can't do what other mature OSes can.
  • Wolfpup - Thursday, October 31, 2013 - link

    It is kind of Microsoft's version of a Chromebook, BUT it still does more. It still has local programs (even if you can only get them through the store). It still has much more of a real file system and has printer (and I think even scanner now?) support, etc. Reply
  • RannXeroxx - Friday, November 29, 2013 - link

    Actually I think you have it wrong. Its people in their late 20s or mid 30s that seem to hate MS but younger people, just like they don't connect to the cold war or the fear of the USSR, they don't connect with the Microsoft Monopoly of the 90's and think of MS as XBox and WP8. Reply
  • prophet001 - Monday, October 21, 2013 - link

    Good post sri_tech. Reply
  • hoboville - Monday, October 21, 2013 - link

    Sorry, but that's an apples and oranges comparison. Chrome vs. Windows isn't the issue. It's Windows RT vs. Windows x86. With RT you get a gimped version of Windows that relies on the M$ Store for apps if you go with RT. If you go with Pro, you pay out the face for a device that is simply a super light, small touch-screened laptop. The great thing about Windows was that it could run a bajillion different x86 programs...not with RT though.

    Ok, so I'll pay $800 for a Pro? For $700, you can get a Haswell laptop with full x86 features (not gimped ARM derpness) on the Windows platform. You'll get the same battery life, a bigger screen, more storage space, the ability to upgrade, and more RAM. Don't forget the fact it has a real keyboard.

    As Anand said: "When we first posted about ASUS’ T100, common feedback was that users would be willing to pay more for an even better device. A Bay Trail Surface 2 could’ve been that device." That's exactly my point, the RT could have waited 3-4 months ditched Tegra and gone to Bay Trail, which is extremely efficient, more powerful, and is x86. For $500 a full x86 tablet with Windows 8 would be a bombshell. It would have most of the features of a laptop while being a tablet. However, M$ is more concerned about roping people in to the M$ Store where they can cash out on apps BECAUSE the RT is a closed platform. They want you to get RT because it means they can milk you for most cash. If you want x86 they will charge you out the wazoo because they know once there, you can use any program you want.
  • trip1ex - Monday, October 21, 2013 - link

    I don't think people want Windows x86 tablets. I think people want to ditch Windows. :) Reply
  • kyuu - Monday, October 21, 2013 - link

    You're confusing "people" with "you".

    Why should I (or people) want to ditch Windows? What does iOS or Android offer that Windows doesn't? As far as I can tell it's nothing but a regression in features either way. OSX? I've used it and had the option for years. Still not interested. Linux? I can see the appeal, but again, I've used it and had the option for years. Nothing has changed that makes it more appealing than Windows for me or your average user.

    ChromeOS? Don't make me laugh.

    You want to avoid the malware situation that ignorant users get into on their Windows machines? Windows RT works for that. People who need more out of their OS than WinRT gives them should know enough to avoid malware in the first place.
  • Hrel - Friday, October 25, 2013 - link

    He didn't say google apps were better, he said it depends on which apps you prefer. Reply
  • theduckofdeath - Wednesday, October 30, 2013 - link

    Chrome OS does support touch screens. The Pixel has a touch ditto.
    And just because Microsoft has services, it is not unanimous with them being of equal quality. Personally, I find Google Docs to be more accessible despite the obvious lack of many features. There's no point in having an advanced online Office service, if it's not as simple to use.
  • thebeastie - Monday, October 21, 2013 - link

    Looks pretty decent, I would feel good about recommending this to my clueless relatives who click and install every single web ad that pops up saying its going to "Improve system performance by %300" and installs garbage and maybe even something that attempts to rob them blind.

    With RT OS I feel assured that won't happen and they can sit and doodle in Office all day and be safe.

Log in

Don't have an account? Sign up now