This website uses cookies to ensure you get the best experience on our website. OK
13 Shares 18 comments

3 things you didn't know about ART runtime

The announcement that the next major version of Android, what we're expecting to be called Android 5.0 Lollipop, will make the switch from the old Dalvik runtime to Android Runtime, or ART as its more commonly known, was a major one. The main reason this is so significant is because by pre-compiling apps the first time they are run the user will experience much faster app performance. This is because the app will always be ready to go, meaning it never needs to load from scratch again. Here's three things you may not know about ART.

androidpit art dalvik
There's more to ART than just a speed boost. / © AndroidPIT

Apps will be faster, but they'll take up more storage

This is a little bit obvious if you think about it: if the app is always kept ready to go in storage then of course it will take up more space than an app that is not. Because the app code is compiled when you first install the app and then kept in memory, rather than compiling every time you launch the app, it means that the storage footprint will be larger.

This may cause a problem for those with limited storage space on their Androids, but increased speed comes at a cost. What this means for Android One and other low-cost devices with limited storage like the Moto E (once ART becomes the default runtime), is another question.

AndroidPIT Storage Apps
If you're worried about how much space your apps take up now, they're only going to get bigger on ART. / © AndroidPIT

ART will save battery life

Another obvious point if you think about it: if all of the apps on your phone are pre-compiled then there's less demand placed on the processor each time you launch them, and less processor demand equals less battery consumption.

The downside is that the first time you boot up your phone it's going to take ages, especially if you have a carrier-branded manufacturer device with tons of bloatware installed. The same goes for the first time you launch a new app, but every time after that will be much snappier.

nexus androidl
While apps may take up more space, ART will help save battery life. / © Google, AndroidPIT

ART is even faster than you think

The current version of ART found on Android is obviously a pre-release developer option to tinker around with. When Google announced the move to ART at Google I/O, they proudly said that ART would be twice as fast as Dalvik and pulled out a nice benchmark graph to prove it. This is the statistic that's doing the rounds on the web right now.

ART Nexus
See the big spike in the middle? That's what Google says ART will do in real life. / © Google / AndroidPIT

What you may not know is that Google also said that other benchmark tests clocked ART at three times faster than Dalvik. Google claims those results are actually more indicative of the speeds you can expect from the Android L release when it is finalized.

As the old adage goes: underquote and overdeliver. Google were obviously just reporting the lower of the benchmark results to avoid backlash at a later date when it only performs at double the current speed. But if ART does indeed prove to be faster than Google has already promised then that's a big win for everyone.

Are you looking forward to ART? What are your thoughts on the larger storage space required for faster app launches?


Write new comment:
  • As a note, if you activate this on a Moto E with very little storage space left, your phone crashes. My phone has done so, and I have yet to find a solution. Everything I have read says that the only way to alleviate this is to send a factory reset to your phone. I am also waiting on feedback from a professional. I am not sure he will tell me any different. I caution anyone who decides to activate ART runtime. Make sure you have EVERYTHING backed up, which I did not. I know, I am very hare-brained, and I am trying here to prevent anyone else from making such a rash decision without full knowledge of the potential consequences.
    Thank you.

  • Mayank Sep 20, 2014 Link to comment

    Is the Art runtime of KitKat same as that of android L?

    • It's closely related but not identical. Of course the L preview had an ''almost done'' version of ART in the same way as the developer option ART in KitKat was ''kind of'' the same thing too. There's obviously more features being rolled into the official ART on Android 5.0 including full backwards compatibility which ART hasn't had before.

  • My thoughts of ART are good, I just think the compability issue is a dealbreaker, Dalvik isn't slow it's fast enough and is compatible to almost everything compared to ART, once the developers of apps actually realises that ART will take over and recompile their apps to support this new runtime, after that I'm happy!

    • The new ART will be backwards compatible though, so your existing apps will still work on the new runtime without requiring the developers (or you) to do anything.

      • I didn't notice that in the Preview version of Android L, or will that be implemented in the full release?

      • Everything I've read from Google has said that the final L release ART will automatically pre-compile apps made for Dalvik. My understanding is that previously devs were asked/required to optimize or something, but then Google looked into it more and figured out it wasn't that hard to do from their end. perhaps ART-optimized apps will be better or take up less space or something, but even if the devs do nothing they will still work on Android 5.0

      • Oh that's nice to hear since that breaks the dealbreaker!

  • 16

    The biggest impact is not the app start but app responsiveness because the garbage collector has been improved dramatically.

  • Den Ce Jul 15, 2014 Link to comment

    You really need to rethink your life purpose if you can't wait 1-5 sec (10-15 sec for game) for app to load....

    • The problem is, you need to open lots of app everyday...

    • I remember when super slow internet used to mean I'd start to load a page and then do something else while it got there. Now I just go from one thing to another without ever stopping to think, chat, eat, sleep, drink, look around... So a little non-responsiveness can be useful too.

    • You may not have lots of downloaded apps, but like everyone you have some essential apps like people, keypad, message, settings, camera, which we all open every hour! anyway if you ok with dalvik, stay with it.

      • Bojan M. Jul 15, 2014 Link to comment

        I'm essentially not saying I disagree with you. If we can get them faster, great, and I'm one of the people looking forward to ART. But, I also support Den Ce's post. Dalvik is not that slow, but we always need everything faster and faster...

    • This is the dumbest argument I have seen regarding smartphone advances. What is the one thing in life that we don't have enough of and we can't alter. Time.... I don't care if it saves me 5 minutes a day, that is 5 minutes I can be talking to my family or doing other things I enjoy. So by your assumption you are the one without a life and would like to waste it staring at a blank phone waiting a full minute trying to call a loved one. Just because you don't care about wasting your time doesn't mean those of us that enjoy our time being alive need to rethink our "purpose". Don't act so high and mighty...

  • How does ART relate to the lawsuit Google lost to Oracle over Java API usage?

    • I'm no developer, but as far as I'm aware ART uses all the same APIs that were disputed in that case, so the shift to ART won't make the patent/copyright/fair use/whatever issues go away. But I don't know anything about the distinction between Java and the VM in that case so I could be totally wrong.

This website uses cookies to ensure you get the best experience on our website. More info

Got it!