Four months after releasing Android 5.0 Lollipop and after two interim updates, Google recently released information about Android 5.1 Lollipop. We had already seen the Motorola Nexus 6 receiving the update to 5.1 so we knew it was incoming and now we've seen it arriving for the LG Nexus 5. As is common with all Nexus software updates, Google rolls out the over the air update over several days as a means of final testing: Google looks out for customer complaints and feedback from those who have received the update. Another important benefit of a staggered software release schedule is that it reduces the impact on Google's servers by avoiding all customers of one particular device trying to download the update at the same time. In the case of the Nexus 5, the update is a little over 200 MB.
We first saw the Nexus 5 running Android 5.1 back in November with a device shown at the Devoxx Conference in the Netherlands. More recently, we've seen the Nexus 5 appearing in the Geekbench benchmarking website running Android 5.1. And looking at some of the detail changes of the Nexus 6, one might be expecting a significant performance boost in storage memory speeds between the different versions but this does not appear to be the case. The Nexus 6 has significantly improved storage speed performance running 5.1 compared with 5.0 because of under-the-skin changes to the kernel, which accelerates encrypted memory access. However, the Nexus 5 did not run the full disk encryption as standard. We've also seen Google fine-tune the Nexus 6's processor. Running Android 5.0, an idle Nexus 6 with the screen on would shut down two processor cores to save battery power. After the update to Android 5.1, now the device keeps all four cores active when it is idle with the screen on. There have been underlying changes to how Android handles 64-bit application code but these are not relevant to the Nexus 5, which uses a 2.3 GHz, 32-bit, quad core processor core.
Another change to Android 5.1 is the addition of Device Protection, which is a means of securing an Android smartphone or tablet with a user's account. Google have also improved the quick settings menu buttons with drop-down options to select a network or device to connect to from the WiFi and Bluetooth options respectively. Google's notes give the as-usual commentary for a software update, citing bug fixes and battery life improvements. Unfortunately, the bug fixes aspect does not include stopping the Lollipop memory leak as we had been led to believe earlier in the year – there are memory management improvements built into Android 5.1 but there are more to come.