When Google announced Android KitKat 4.4 ate last year, one of the features that stole away the thunder was a new runtime that was added to Android. Until, KitKat all the Android phones used the Dalvik run time. Dalvik basically is a JIT Compiler, or a Just in time compiler. This means that when you fire an app up, it is compiled right on the spot. If the app is heavy, that is why it takes a fraction of a second to load the app up.
To do away with this performance issue, Google had added ART as an optional runtime in Android 4.4. ART compiler is an AOT or, Ahead of Time compiler which basically compiles all the apps in the memory when you boot your device. Therefore, whenever you open an app it is pre compiled in the memory, giving you a better overall experience. Users on ART therefore have experienced better performances as well as battery backups. However, the issue with ART has been that not all apps are optimised for it, we are gradually getting there though.
However, according to a post on XDA Forums, Google has been satisfied with how ART has performed and is ready to make the move permanent with the next major Android update which could be the Android version 5.0. The only side effect of running ART we felt was that when booting up a phone for the first time, the device takes absurdly long, even 5-7 minutes on occasion.
AOSP has already made the move to ART full time and posted the following message signalling that the move is inevitable.
Dalvik is dead, long live Dalvik! DO NOT MERGE croot cd libcore repo start dalvik-is-dead-long-live-dalvik . repo sync -c . git rm -r libdvm git add JavaLibrary.mk (after removing libdvm references, adding explict core-libart references) git add Docs.mk (after replacing references to libdvm with libart) git add benchmarks/Android.mk (after adding explict core-libart references) git add Android.mk (after removing dalvik-host target) git commit -a -m ‘Dalvik is dead, long live Dalvik! DO NOT MERGE’
Switch from core to core-libart