Just...WOW...massive speed increase using ART cache

[JeffDenver]

I switched from Dalvik to ART cache...holy crap. Apps start way faster now. They seem to work faster too...switching between pictures in the gallery is smoother and faster than before.

To enable it, activate developer mode by goting to Settings then "About Phone" and tapping on the build number really fast until it tells you developer mode is enabled (at least 7 taps...it will remember this when you reboot too, so you only have to do it once). Go to "Developer options" that now appears in the Settings menu. Click on "select runtime" and choose ART. You can swap back later if you want.

It will re-start and will re-compile your apps or something. Took about 15 minutes for me.

I am a pretty advanced user but not an expert...does anyone know if there are downsides to using ART right now?

 

[Gekko]

no thanks. i'm sure the Gremlins will appear soon. but thanks for being our guinea pig. please report back later. enjoy.

 

[tr-1]

I switched from Dalvik to ART cache...holy crap. Apps start way faster now. They seem to work faster too...switching between pictures in the gallery is smoother and faster than before.

To enable it, activate developer mode by goting to Settings then "About Phone" and tapping on the build number really fast until it tells you developer mode is enabled (at least 7 taps...it will remember this when you reboot too, so you only have to do it once). Go to "Developer options" that now appears in the Settings menu. Click on "select runtime" and choose ART. You can swap back later if you want.

It will re-start and will re-compile your apps or something. Took about 15 minutes for me.

I am a pretty advanced user but not an expert...does anyone know if there are downsides to using ART right now?

CNET just did an article on this but since it's CNET, it's not very informative
Google tests ART foundation in KitKat for faster Android apps | Mobile - CNET News

 

[Shilohcane]

After reading this article you may have something I will try.

Google debuts ART in KitKat, aims to change Android

 

[JeffDenver]

Also don't try this on other AOSP builds right now as it makes the OS crash and become unusable.

Google debuts ART in KitKat, aims to change Android - GSMArena.com news

So a word of warning to non-Nexus people.

Does not look like there are any side effects other than apps taking longer to install and taking up slightly more space.

 

[junglejunkie]

I'm giving it a shot right now!

 

[Robbie317]

no thanks. i'm sure the Gremlins will appear soon. but thanks for being our guinea pig. please report back later. enjoy.

Why not try it.... Seems to be something beta Google will eventually make a full time option... I'll try and let you know how it goes.....

 

[JeffDenver]

Google maps satellite view is working MUCH faster. Tiles populate very quickly.

 

[Shilohcane]

So a word of warning to non-Nexus people.

Does not look like there are any side effects other than apps taking longer to install and taking up slightly more space.

I wouldn't make that statement since it is in BETA for a reason. Dalvik runs Java like App code with the JIT emulator that each time you use the App it converts the higher level Java Source code into the native CPU code for the specific processor (SnapDragon 800) that is actually in your phone to executes. Sure ART method of compiling every App to execute in native mode on your SnapDragon 800 is much faster when you are starting up Apps. However what happens when these Apps on your phone get updated with new downloads that is expecting the App to still be using the JIT method is what I want to know first. I'm not worried about converting all Apps to native code. I'm just worried what happens when you get a update from Android OS or the Apps are upgraded with patch updates.

 

[anon(847090)]

So a word of warning to non-Nexus people.

Does not look like there are any side effects other than apps taking longer to install and taking up slightly more space.

here is an article from AP. part 2 with detailed explanation is coming
Meet ART, Part 1: The New Super-Fast Android Runtime Google Has Been Working On In Secret For Over 2 Years Debuts In KitKat

 

[anon(847090)]

I wouldn't make that statement since it is in BETA for a reason. Dalvik runs Java like App code with the JIT emulator that each time you use the App it converts the higher level Java Source code into the native CPU code for the specific processor (SnapDragon 800) that is actually in your phone to executes. Sure ART method of compiling every App to execute in native mode on your SnapDragon 800 is much faster when you are starting up Apps. However what happens when these Apps on your phone get updated with new downloads that is expecting the App to still be using the JIT method is what I want to know first. I not worried about converting all Apps to native code I'm just worried what happens when you get a update from Android OS or the Apps are upgraded trying to patch updates.

read the article i posted above. whenever an app is downloaded or updated it convert to machine code when installing, hence longer time to install

 

[JeffDenver]

I wouldn't make that statement since it is in BETA for a reason. Dalvik runs Java like App code with the JIT emulator that each time you use the App it converts the higher level Java Source code into the native CPU code for the specific processor (SnapDragon 800) that is actually in your phone to executes. Sure ART method of compiling every App to execute in native mode on your SnapDragon 800 is much faster when you are starting up Apps. However what happens when these Apps on your phone get updated with new downloads that is expecting the App to still be using the JIT method is what I want to know first. I not worried about converting all Apps to native code I'm just worried what happens when you get a update from Android OS or the Apps are upgraded trying to patch updates.

Is JIT the same thing as Dalvik? Is it a component of Dalvik, or something separate?

I just updated Shazam, Beautiful Widgets, and Google maps. They appear to be working normally still. No issues with updates on them.

 

[Shilohcane]

read the article i posted above. whenever an app is downloaded or updated it convert to machine code when installing, hence longer time to install

Still1 I am am big fan of yours on this board and you know a 1000 times more than I do. I am just a old mini computer programers that has seen a lot of patch code tricks but know little about Android's OS. It was a surprise to me they were still using emulators methods like JIT that converts to native code every time I start up a App. I want to turn on ART but Hangout kicked my ****. So I am on the sideline till I see how ART works for the masses.

I started up a thread in the Kit Kat OS forum that is a better place for this thread since if we keep posting here there is going to have a lot of people trying this that aren't ready for this advanced BETA stuff. Please post your article on the Kit Kat forum since I really do want to see people that know what they are doing in the Android world review this.

 

[anon(847090)]

Is JIT the same thing as Dalvik? Is it a component of Dalvik, or something separate?

I just updated Shazam, Beautiful Widgets, and Google maps. They appear to be working normally still. No issues with updates on them.

JIT is part of Dalvik(the virtual machine). JIT analyse and translate the code to machine code to run on Dalvik.
so every time a code is executed in apps JIT will translate it and the output will be run on Dalvik

now with ART, JIT is taking a different form. instead of running on phone when needed ART will precompile to machine code when installed.
so now after app installation on ART, JIT is no longer needed.

so to answer what Shilohcane was asking. when you convert from dalvik to ART, it will convert all code to machine code when it reboots

so when an app is installed/update ART will convert to machine code at that time

 

[JeffDenver]

JIT is part of Dalvik(the virtual machine). JIT analyse and translate the code to machine code to run on Dalvik.
so every time a code is executed in apps JIT will translate it and the output will be run on Dalvik

now with ART, JIT is taking a different form. instead of running on phone when needed ART will precompile to machine code when installed.
so now after app installation on ART, JIT is no longer needed.

so to answer what Shilohcane was asking. when you convert from dalvik to ART, it will convert all code to machine code when it reboots

so when an app is installed/update ART will convert to machine code at that time

Ah...ok. I think I get it now. JIT is being applied at install instead of when you launch the app.

Just tried Google Earth...totally different experience now. It is not just that apps start quicker...some of them run faster too even after they start. Titles in Maps and detail in Google Earth are definitely loading faster.

 

[JeffDenver]

Still1 I am am big fan of yours on this board and you know a 1000 times more than I do. I am just a old mini computer programers that has seen a lot of patch code tricks but know little about Android's OS. It was a surprise to me they were still using emulators methods like JIT that converts to native code every time I start up a App. I want to turn on ART but Hangout kicked my ****. So I am on the sideline till I see how ART works for the masses.

I assume it will let you convert back too. I am still seeing the Dalvik setting in developer options.

 

[Shilohcane]

Still1 do you see a problem if someone backs up their Apps that are running ART with Titanium Backup and then reloads that backup to another Android phone that may not have a Qualcomm Snapdragon 800 processor?

 

[JeffDenver]

Still1 do you see a problem is someone backs up their Apps that are running ART with Titanium Backup and then reloads that backup to another Android phone that may not have a Qualcomm Snapdragon 800 processor?

Thats a good point.

 

[anon(847090)]

Ah...ok. I think I get it now. JIT is being applied at install instead of when you launch the app.

Just tried Google Earth...totally different experience now. It is not just that apps start quicker...some of them run faster too even after they start. Titles in Maps and detail in Google Earth are definitely loading faster.

exactly but in Dalvik, JIT is not only called at start up. it will run whenever needed(when code is executed) when u r using the app.

for example when u delete an email in gmail if a code is executed then JIT is called, then u do an archive JIT is called again.

with ART JIT is no longer used after the installation. thats why u r seeing faster responses at startup and when using the app(Google earth in your case).

- - - Updated - - -

Still1 do you see a problem is someone backs up their Apps that are running ART with Titanium Backup and then reloads that backup to another Android phone that may not have a Qualcomm Snapdragon 800 processor?

Thats a good point.

that's def a good point. will check it out later but my assumption is art backup can be run on JIT but the other way might have problems

 

[Zendroid1]

I read at XDA that titanium doesnt work with ART turned on.