NEW YORK: Developer Francisco Franco reveals that more than just end user benefits, the update will significantly boost the performance and responsiveness of Google’s first phablet.
According to Franco, there are two major changes to Android 5.1 that benefits the Nexus 6 specifically. The first is actually rather surprising. It turns out that Android 5.0 initially didn’t make full use of all four cores of the Qualcomm Snapdragon 805 running inside, a rather puzzling implementation that made the Nexus 6 feel sluggish. Android 5.1 rectifies that and now the system makes use of all cores, allowing the kernel to distribute tasks on all of them.
The second reason is a bit more complicated though still related to the multi-core nature of the Nexus 6’s CPU. Qualcomm implements what is called a migration boost routine. In a nutshell, this routine takes effect when one task (technically, a thread) moves from one CPU core to another. The boost makes sure that the destination core is running on the same speed as the originating core. The purpose of this migration boost is to make sure that the user doesn’t perceive any lag while processes are juggled behind the scenes, but it also incurs not only added battery consumption but also, ironically, actual sluggishness. Franco says that Google seems to have realized that and decided it was not worth the trade-off and disabled it in Android 5.1.
That said, the developer thinks that there is still much work to be done. In particular, there is still some CPU migration boost happening when touch events happen, which is most likely every time a user actually picks up his or her phone. Franco hopes that Google will also turn this off in a future release.
