ART is 50% faster than Dalvik
The tech media is all a-twitter today, copying each other's stories about the new runtime environment in the "next release" of Android. A few, however, hint at the truth: that ART (Android Run Time) is already in Android today. (The only change, really, is that the old Dalvit engine will be removed from the next Android release, make ART the default.)
If you own a recent Google phone, you might be able turn on ART right now. No root required. Here is how I did it:
The ART switch is found in Settings, in the Developer Options section. In some devices, developer mode is turned off by default, and so the first steps are to turn it on.
1. On your Android, tap Settings, and then see if Developer Options is listed. If not, follow these steps to turn on developer mode:
a. Open About
b. Tap Build Number seven times. Developer mode is enabled. (During the tapping, you might see warning messages; ignore them.)
2. Go back to the Settings screen, and tap the newly available Developer Options.
3. Tap Select Runtime.
4. Choose Use ART.
5. Agree to allow Android to reboot.
Following the reboot, you will have to wait some time as Android converts apps from Dalvik to ART mode.
Now, the tech media are making claims about ART without having tested themselves. Lazy of them, eh? I've run my Nexus 4 phone on ART for a month now. Here are their claims, with my experiences in brackets:
- Installs take longer (I don't notice this)
- Apps take up more memory space (I don't notice this)
- Some apps don't work (No problem for me, but there is an exception I found, below)
- Battery life is longer (I don't notice this)
- Things run faster (Yes!)
Some sites claim the speed increase is minimal, but I can feel the change, which tells me subjectively it's more than the 10%-20% they claim. Turning to objective measurement, using the Quadrant Standard benchmarking program, I found that apps run 50% faster with ART. That's pretty good for a free upgrade.
And yes, you can switch back to Dalvit, should you find that a critical app doesn't run. All of mine work, even one that hasn't been updated by its developer in two years. But then I read that AutoCAD 360 fails. I don't normally use the program, and so I installed it last night. Sure enough, shortly after launching, it crashed on ART.
(Google is disabling Dalvit after it lost a law suit with Oracle over the use of Java in Android.)