Android 5.1 fixed a lot of issues, but apparently a persistent memory leak was not one of them.
A rather lengthy issue tracker on the Android Open Source oject indicates that many Nexus 5 owners are still seeing significant memory resources draining, an issue that first popped up with Android 5.0 has persisted since.
There is some hope, as a post from someone on the Android development team says the problem has “been fixed internally,” though there isn’t a timeline for when it will be released to the public.
The problem can be diagnosed by going to Settings > Apps, then scrolling to Running. If the system memory is eating up an unsually large amount of RAM (over a gigabyte, when no apps are running), then you may be bitten by this bug also, which can slow your device to a crawl crash apps. The best bet is to restart the device from time to time, though that’s obviously an annoying, b-aid approach.
The impact on you: This shouldn’t hold you back from jumping up to Android 5.1 if you’re on a Nexus device, as it definitely speeds up performance fixes many performance issues, such as a rather annoying bug that kept crashing the Contacts app. This may explain why hardware partners carriers have been slow to update to Android llipop.
