Skip to main content

Nexus 6 Performance With Android 5.1

Conclusion

The Android 5.1 update brings several improvements to the Nexus 6, including a number of bug fixes and UI refinements. It also enables OpenGL ES 3.1 support and the Qualcomm VP8 hardware video decoder. Unfortunately, it does not enable hardware based storage encryption or fix optical image stabilization for the rear camera. There’s also no improvement in display calibration.

The other Nexus 6 specific changes are a mixed bag. Utilizing NEON instructions for the encryption engine does speed up data reads for larger block sizes, but seems to hurt performance when reading and writing smaller data blocks. Disabling Qualcomm’s thread migration boost feature reduces performance by up to 20% in specific workloads where the CPU cores aren’t fully utilized. However, this did contribute to a noticeable gain in the PCMark battery life test.

The final big change in the 5.1 update for the Nexus 6, keeping all four cores online all the time, is harder to evaluate. Typically, our phones perform a number of tasks in the background keeping us updated on events happening in the world. With only two cores generally available, which was the case when running the initial 5.0 build, these tasks could interrupt the foreground app or UI interaction, producing a noticeable lag and hurting the user experience. Having more cores available to service these background tasks should improve responsiveness. The downside is that static power drain is increased, reducing the battery life gained from disabling the thread migration boost, and the thermal/power envelope is decreased, which can keep cores from reaching max frequency and reducing performance.

In the end, the performance penalty seen in specific cases is not enough to outweigh the benefits from the 5.1 update. It’s important to have realistic expectations though. I don’t expect these changes to be permanent, but rather stepping stones on a path to a more efficient CPU governor.

Matt Humrick is a Staff Editor at Tom's Hardware, covering Smartphones and Tablets. Follow him on Twitter.

Follow Tom's Hardware on Twitter, Facebook and Google+.

  • ZolaIII
    Just to point out how CPU clocking logic effect busses on Qualcomm SoCs. For instance if 1 core CPU frequency fell down under the minimum frequently than is tied to max bus frequency it will narrow & memory bandwidth & this will impact GPU performance badly under GPU intensive tasks. For me it looks like that on-demand scheduler is working more as it should under 5.1. Including patch sets from Linux kernel 3.12~3.21 (on demand to use more mid frequencies) should be just enough to address performance regressions still savings (even litle more) juice. They should really disable file encryption on any ARM V7 build. Switching to last stable GCC should increase user experience greatly, it's funny they still use 4.6. To address possible fluctuations & determine real impact of changes do the tests again with performance governor & disable MP decision (hot plug) for GPU tests.
    Reply
  • zodiacfml
    Ouch. Glad I bought the N5 last year.
    Reply
  • endeavour37a
    I have an old LG G2 and it does not even have filters :(
    Reply
  • theusual
    Be sure to upgrade 'Android System WebView' through Google Play as well as for me it didn't upgrade automatically and was causing app issues.
    Reply
  • Plyro109
    Sorry. Browser seems to be autofilling and submitting in every comment thread I visit.
    Reply
  • Tracy Kohler
    Get that stupid bar off the top of my screen please! It takes up a whole INCH of screen space (and vertical space is LIMITED already on this wide CRAP they call monitors today).

    I guess I'll have to come up with a way to kill it and still be able to navigate, other than scrolling. Go back to pages with a bar at top or bottom for index. While your at it FIRE the guy/gal who decided an inch of real estate on a monitor is OK to block all day. He/she will only piss off users over and over (hired from win8 team?...LOL).
    Reply
  • Senecaz
    TL, DR : Lollipop s*cks! next update please...
    Reply
  • musical marv
    15881932 said:
    TL, DR : Lollipop s*cks! next update please...
    Why do you say Loliipop sucks?

    Reply
  • musical marv
    15881932 said:
    TL, DR : Lollipop s*cks! next update please...
    Back Up what you post here and do not ignore it.

    Reply
  • endeavour37a
    I thought Tom's was a place we could have opinions and points of view we could share and express freely, how does one back up what they like and don't like? I sort of like 5.0 but it's just fine if some else does not, I ignore a lot of stuff myself.
    Reply