Android 7.0: Better performance, longer battery life

Every time the software on our phones receives a big update, we hear how it will perform better and use less of our battery. While it's often true, the ideas and how they are implemented need plenty of fine-tuning to meet expectations. Android 7.0 improves on two existing features to help them live up to their full potential: Projects Doze, and Project Svelte.

The goals are simple — find ways to make the phone less power hungry when you're not using it, and better management of background processes. All software is built with an emphasis on performance and efficiency, and an operating system so much more so. We'll take a look at the changes and see how they could have an impact.

Project Svelte

My memory is managed poorly I think

Project Svelte arrived in 2013 with the release of Android 4.4 KitKat as a way for the OS to perform better on lower-end phones. On that front, it did succeed, but we expected bigger changes than we got. For a good idea of what Svelte's original intentions were, look no further than Android One. The goal was to create inexpensive hardware that runs the latest version of Android well enough to recommend.

With Android 7.0, the project continues to cut down on the performance impact by having an even better system for management of background processes.

Changes to Svelte address two specific and important issues that force apps to run in the background

Android is very different from iOS. Any developer can pay a very small fee and publish an app in Google Play alongside names like Facebook or Samsung. Provided the app has no malicious code, it will go live for everyone to install, and unless it gets reported for inappropriate content or actions it gets to stay (though Google says it does do an automated check of every app before pushing it live). That's a far cry from every app submitted going through a manual approval process, and it means that apps aren't being rejected because they don't follow best development practices. Behavior of some of the current APIs doesn't help, and even the best apps can wake up and use resources too often due to an errant process.

Improvements to Svelte in Android Nougat fix two glaring issues:

  • Apps check to see if the network changes using what's called a broadcast receiver. When a change happens, every app listening for the change through the default method wakes up at one time and tries to process the data about the change.Think of how your phone acts when it's first started and everything tries to happen at once, and you have an idea of why this needs some sort of improvement. When targeted towards Android 7.0, apps can only listen for network changes through the main thread (what runs when the app is awake and you're using it) so they aren't waking up every time you switch networks. This will use less RAM and CPU time, which means our phones will perform better and use less power.
  • In previous versions of Android, apps were able to listen on a similar broadcast receiver for a picture or video to be taken. When that happened, every application that was listening woke up and tried to process the data at once. As above, that isn't very good on the performance front. In Android 7.0, the new picture and new video broadcasts can't be sent. That means even if developers don't update existing apps, they'll never be told to wake up when a picture or video is taken.

For apps to do many of the things we want them to do, they have to stay alive. Slimming down the things they do while they're quietly waiting to become active once again by eliminating unnecessary functions means fewer apps will be running instead of sleeping when they are sent to the background.

Project Doze

Doze doing what it's supposed to do

The way things work now, you either love Doze or you don't see Doze doing anything noticeable on your phone. That's because of the way it works.

When Doze debuted in Android 6.0, its intent was to defer CPU and network activity while your phone's screen was off, unplugged, and motionless. If all three of the criteria were not met, Doze would not kick in and apps would continue to run as normal. This worked great while in the office and at your desk, but as soon as it went into your pocket Doze stopped doing anything and the benefits ceased.

A two-stage Doze lets your phone use less battery while you're up and moving, too

The behavior change in Android Nougat is simple. Doze now has two stages: one is when the screen is off and the phone is unplugged, and the other is when the phone is also motionless.

When your phone is running on just the battery and the screen has been off for a set amount of time, applications will stop directly accessing the network, and activities like syncing and other jobs are deferred until a predefined amount of time passes. Then, a short maintenance window allows them to perform normal background functions. This part works while your phone is in your pocket or subject to other forms of motion.

When the phone has also been still for a set amount of time, all the Doze restrictions — additional things like apps waking in the background or listening for what's called an alarm (not the kind that wakes you in the morning, those are unaffected) or looking for the current location — are applied on top of the network and jobs deferrals. The maintenance window still regularly appears, but between those windows your phone is barely alive and not doing much until you pick it up.

We know how well Doze works (when it hasn't been modified by the people who built your phone) while the phone is still. Now we'll also see a benefit when we're up and moving, too.

Will the changes to Svelte and Doze fix every performance and battery issue? The answer, of course, is no. But these changes are logical steps that address two very specific things that needed addressed. the result will prove to be better than what we have now, even if it can't solve everything.

Jerry Hildenbrand
Senior Editor — Google Ecosystem

Jerry is an amateur woodworker and struggling shade tree mechanic. There's nothing he can't take apart, but many things he can't reassemble. You'll find him writing and speaking his loud opinion on Android Central and occasionally on Twitter.

  • Nice! Posted via the Android Central App
  • Can someone tell me why my Galaxy A3 2016 A310-M runs just about as smooth as my 5x, but manages to get an easy 2 days battery life while easily approaching 3hrs of screen on time, and still running 5.1.1. I don't get it. I understand it's a 4.7" AMOLED screen 720p but still it's Android over all.
  • Its just for that reason. lower res screen. Posted via the Android Central App
  • Yup Posted from outer space on my Moto X Style
  • It's not just screen resolution, it's more then that. Just yesterday I had over 5hrs screen on time, with 19hrs up time, and still had 15% battery life left all on a 2300mah battery . Its 2016 and a nexus phone still can't last a full days use. I have both a 6P and a 5X, neither can last a full day. other 1080P screen phones crush them in battery life, funny thing is those phones are considered midrange by some. Google needs to fix something, and do it quick.
  • Doze FTW Posted via my glorious Nexus 6P
  • I'm on Android Nougat developer preview 5 right now I started back with dp1 one in march loving this phone as I am a networker security Expert at work.
  • Doze, Svelte, Volta...etc. Honestly, nothing has changed. I get about a day of use with my phone currently and have gotten about a day of use with every phone I have owned since switching to a smart phone 5 years ago (I've been through maybe 7 phones I think). Google loves to throw these new names at us with promises of batter battery life and people just gobble it up. I bet when I grab a 2016 Nexus I will get about a day of use out of it before needing to charge. I just hope by the time the next new battery saving name comes around Google will have discovered how to get me my emails reliably when my phone is Dozing or whatever while I am carrying it around. Having a bunch of emails show up suddenly when I pick it up after I haven't been using my phone for a few hours is annoying.
  • Which phone are you showing off
  • I don't know what that means. Currently I am using a Nexus 5X. I use the phone throughout the day and before I go to bed I throw it on the charger at maybe 20%. I did that with my EVO Shift, Nexus S, EVO LTE, Xperia Play, Galaxy S3 and my Nexus 5 (The Nexus 5 was probably closest to being dead but always got me through a single day of use). They would all get me through about a day of use before needing a charge and all these programs have been introduced since then.
  • Nougat made a very noticeable difference on my Nexus 6P. When I was running Marshmallow 6.0.1 it could barely last a day (less than 10% or required a charge on the way home) and my usage on Project Fi was about 1.5-2GB per month. Now running the Nougat 7.0.0 developer preview I have ~ 30% battery remaining at the end of the day and my Project Fi usage is less than 1GB per month (.8-.95GB). I didn't install or uninstall any apps between the OS update nor did I change my usage/behavior. I was apprehensive about installing a non-release OS at first, but I have been very pleased with this preview. I’m also running iOS 10 previews and Windows 10 insider updates on my other mobile devices and not encountered an issue there so I gave Google a shot. My wife loves the N Cat Easter Egg - she has amassed a sizable collection of felines.
  • Prior to Nougat, Doze only really helps you if you forgot to charge your phone at night. It reduces battery life loss down to negligible while your phone is idle. Before Doze, Android phones tend to suck a lot of juice even while idle. With Nougat, you get the same benefits even outside of your house when the phone is in your pocket. I see noticeable improvements coming. Of course, it really depends on how you use your phone. If you're the type to have a high screen-on time of usage, you won't be benefiting much from these architectural improvements, since the phone is constantly awake in your case anyway.
  • And every new phone you have had has been more powerful and performed more functions while still giving you that full day of power without a substantial battery increase compared to the hardware processing power increase on top of more background functions.
  • Bullsh!t. Every mobile website and every app is more and more resource hungry, same as the resources and battery increased. Nothing really changed. I remember when Google Maps was updated on whatever phone I had at the time, and it suddenly became really laggy and jittery, and made me want to buy a new, more powerful, phone (which I eventually did). Just open this website in your browser, on your current flagship, and see how much it sucks (including CPU).
  • This site sucks on a mobile browser because it's downloading ads from a dozen different ad servers. That's not Android's fault, it's AC's. But your rant has nothing to do with the comment you responded to, which is accurate. Every new phone is more powerful than it's predecessor while offering similar battery life.
  • I'm not saying it's Android's fault, or AC's. It's just the world we live in. But the hardware has progressed the same way the resource consumption has, so we're basically on the same boat as 5 years ago.
  • I agree and disagree. Phone battery life is wayyy better under the hood. But, with larger and higher resolution displays which consume even more power, and the onslaught of additional features, we still hang around that 1 day mark. If you crammed all the battery tech and battery-saving tech into an older say, Evo 4G, it'd probably run for a week on the less powerful CPU, smaller screen, etc.
  • Same has been said of every Android version, etc. I'll believe this when i have first hand use , but not until then..
  • Not to mention it will take almost a year for many of us to even see 7.0 Posted from my Samsung Galaxy S7 Edge I HAVE TECHNOLOGY A.D.D.
  • This year may be different I think, considering LG V20 is coming straight put of the box with it in about a month so I think Samsung will really try to push it out quickly because that could cause a loss of sales and disgruntled customers. Or we could see no change at all and they could do what they always do. Who knows Posted via the Android Central App
  • Yes,Samsung can push it out quickly,and then the carrier's screw Posted via the Android Central App I see the Note7 and the S7/Edge getting Android 7.0 between January-march,2017,directly attributable to the US carriers.
  • According to an article on DL, the unlocked Galaxy S7/S7 Edge that debuted earlier this year are still on either the May or June security patch. They haven't received an update since they launched, so it's not just the carriers, the OEMs have to actually push the updates to their devices. With universally unlocked devices like the S7/S7E, there's no excuse for Samsung not to be on the current security patch, especially considering that since it launched, the Quadrooter patches were released.
  • Samsung has actually been great about updates. They've pushed the security updates every month including the August patches in the latest build. It's been a nice surprise after dealing with carrier locked phones for so long.
  • Those were for the carrier locked devices. The universally unlocked Galaxy S7 & S7 Edge, the ones that run on any US carrier (CDMA and GSM) are apparently a few months behind in terms of security patches. Which as I said is ridiculous since those should be the ones that can push out updates and patches faster due to zero carrier involvement. There's no excuse for those two devices not to be their most up to date devices in terms of software. In fact that should be the number one selling point of those devices. They sell only at full retail price so what's the upside to owning one? The ability to change carriers and use the same phone? That's not really worth the price you pay.
  • Mines on the July security patch. (S7 edge international)
  • Ok, let me be more clear. There are two different unlocked Galaxy S7 and S7 Edges. The international unlocked that is GSM and is sold to essentially everyone outside the US, and what I call universally unlocked, which has both CDMA and GSM bands for all 4 major US carriers. The GSM unlocked that you have was released around the time the carrier locked models were released, whereas the universally unlocked model was released last May. That is the one I'm talking about, ok.
  • Nothing is going to change. Every manufacturer is going to try and push 7.0 to their latest device. Previous years models may get it 6-8 months later, and by then most of use will have already purchased a new phone with 7.0 already on it, waiting till next year to see 8.0, and the cycle continues. Nothing changes.....
  • well, that's becuz u need a nexus device. I trying to tell u what to buy, but these OEM's ( manufacturers) don't care about updating their devices. As long as u continue buying their phones, they will continue not updating in a timely manner. Nexus phones are the only devices that get updated with all the goodness google releases. why would u want a devices that have u waiting just about a year or over for something u should've had months ago.
  • There is a lot more to a phone than software version. I can ask this, why buy a Nexus when you can get a Samsung with better hardware and features out of the box? They may not update as quickly, but I can do a lot more with TouchWiz than I can stock Android. Google likes to borrow Samsung features and make them native to Android over time. Posted via the Android Central App
  • What you call features, I call bloat.
  • See my post above. It's not just about updating for new features, it's also about security.
  • Most normal people just want a phone to last more then a day, and take pretty pictures. Today I asked 10 people at work, all pretty smart , what security patch they had on their phone. They all looked at me with this empty stare. None of them know what version of Android their running. They just want, to not have to plug in their friggin phone mid day to charge....
  • So what your point? Just because the average user knows nothing about security and keeping their devices up to date, we should give these companies a pass? It's up to these companies to protect their customers and keep their personal data secure. The updates are automatic, all the customer has to do is press a button, something a chimp can do. My point was, Samsung finally releases a pair of universally unlocked devices for the US, a way for them to bypass the carriers and truly keep their customers up to date, and they drop the ball. Samsung has no excuse this time, it's all on them. But just because the customer isn't knowledgeable about keeping their mobile devices up to date, that's no excuse for these companies to get lax in terms of updates and security.
  • I hope my Moto G4+ will be seeing that Android 7 update very soon after release.
  • I've heard that before. I'll believe it when I see it. Posted via the Android Central App
  • Great read Jerry. Thanks man. By the by, totally saved this article for my wife when she asks me what Doze is. Posted via my G5
  • I sincerely hope that Google can one day truly improve battery life quirks on Android. This whole project svelte and doze thing, in theory, sounds like it's supposed to really improve the way third party apps affect battery life, especially when NOT the main process. This is such a major issue with Android that makes battery life so inconsistent. Sure there's a TON of variables, but the fact that a third party app can be working in the background so much and kill the battery just sitting idle, without you knowing until you check your phone with it dropped 20%, is unacceptable. It can happen with any phone, no matter the manufacturer. To me, it's the most major drawback to Android. Here's hoping I guess. Posted via the Android Central App
  • I'm just glad they finally fixed the broken size that would stop you from getting notifications after the phone sat for too long. When I was running the 7.0 beta, that no longer seemed to be an issue. I have to disable doze on all of my Marshmallow phones.
  • Android 7.0 has been much worse on battery life with my 5x. Not impressed
  • And yet people are still complaining of poor battery life with the preview OS. The only thing that will significantly improve battery life is another 1000 mAh. Posted via the Android Central App
  • It's pretty clear that there's a long way to go on the software side to improve battery life. Hence the reason why they're constantly coming up with all these new "projects", because they know there's an issue. Sure the bigger the better with physical battery capacity holds true, but it's not the end all be all. A 4000mah battery is gonna drain at the same rate as a 3000mah battery with the same rogue app that's slurping on it. Just has a bit more for that app to drain. Still not good though. Posted via the Android Central App
  • Preview OS. Remember that. Posted via the Android Central App
  • Am I the only one who faced major battery buff after marshmallow with doze? My nexus 6 felt like having twice the amount of battery and still does a great job Posted via the Android Central App
  • There's already a mobile OS that's very, very power efficient. It's called iOS. And it's why almost no apps can ever keep running in the background. Like if I have a bunch of photos to upload to Onedrive, I have to keep tapping the screen to keep it from timing out (even if the screen is set to never turn off) And then there are apps that do run well in the background. Like Facebook. I assume Zuck has paid top dollar to apple for them to allow it. And it's why Facebook is one of the few iOS apps that destroys battery life. So Google, by all means. Keep turning Android into iOS. You are almost there. I really don't care. Whenever I need to get something done, I go back to my desktop pc anyway. Unlike Android and iPhone crapps, x86 windows programs actually work.
  • It's actually called Android because Android is better in everyway possible no denying that Posted from my Moto X 2nd gen and my Nexus 9 both on Android Marshmallow
  • Too bad Apple has such tiny batteries in their devices, they can only match some flagship Android devices in usage. As for Window, I almost agree. A good SSD in a laptop with a decent battery and I can get 6-8 hours with no performance issues. Except when Microsoft decides to wake up my PC to check for updates and forgets to put it back to sleep. Then my battery is dead when I go to use it... Posted via the Android Central App
  • Given the never-really-fulfilled promises of Butter, Volta, and Doze, allow me to be skeptical about this. :(
  • And a month from now the note 7 will most likely be a fading memory on AC because it's gonna sit on 6.0 for quite some time, while the the new nexus' run the latest and greatest along with the 6P and N6. Posted via the Android Central App
  • Serious skepticism from everyone. Odd, Doze on my Nexus 7 2013 seems to help standby, which is what it was supposed to do. My G5, which doesn't have a large battery by today's standards, gets amazing battery life. Better than my Note 4 which had a bigger battery. The G5 is actually providing the best battery life of any phone I've ever owned. Posted via the Android Central App
  • I have to agree..
    Sent from my Sprint G5
  • OMG! It's amazing! but it's 3 months are up. I'm getting Android Oreo. Nougat is so 3 months ago. Because Android doesn't give a new OS time to be established before announcing a new Android OS. So F U Android!
  • lol
  • "We know how well Doze works (when it hasn't been modified by the people who built your phone) while the phone is still. Now we'll also see a benefit when we're up and moving, too." Unless, of course, you NEED to get certain notifications while you're walking around with your phone. Instead of getting them immediately, you're fat, dumb and happy thinking nothing's going on until Google decides it's time to say "you missed something important." Google needs to make the underlying code more efficient, not apply band-aids that turn your smartphone into a dumb one half the time. "[Apps] aren't waking up every time you switch networks. " But how many times a day do you REALLY switch networks? For most people this will have a miniscule effect on battery life.
  • There's a setting to disable optimizations for apps you choose, so they aren't affected by Doze
  • No, this Whitelist is for App Standby, not for Doze. If Doze had a Whitelist, it would not be as broken as it is right now. I want to control, which apps can still get Alarms.
    In MIUI, most apps are not allowed to wake up by an alarm at all by default and the user has full control.
    Also, as long as Google allows apps in the background (not services) to continue using CPU, Doze is just a workaround.
  • when i saw this article in my news feed i thought that Nougat had been released :-(
  • The preview saved my phone. I went from like 2hrs SOT to just under 4. I'd kill for more but it definitely made a big difference. Posted via the Android Central App
  • Sad that my Nexus 5 doesn't qualify for this, but maybe it is now time to try a custom ROM again.
  • It's all very nice and pretty. But we've been promised lots of projects like these for a while but the reality is very different. I'll believe it when I see it.
  • Maybe people just expect too much. Posted via the Android Central App
  • I dunno....I expect my nice new galaxy s7 edge to last longer than my wife's 2 year old iPhone 6 considering it has a bigger battery Hell I'd settle for lasting as long as her iPhone
  • Excited to see how well this works. My phone is always plugged in at night and every other time my phone is moving so Doze as it is now does nothing for me. Hopefully this works much better.
  • Between software improvements and hardware improvements every Samsung Note I've owned has had better battery life than the previous. Note 2/Note 3 are a joke compared to the Note 5 for battery life in stand by, have less on screen time, and take forever to charge. Posted via the Android Central App
  • And what new Android release doesn't promise improved performance? The OS is not as good as Windows Mobile or iOS. I am a Android user by the way. But over time, Android always slows to a creeping halt. Windows Mobile does not.
  • That's weird, Windows Phone slowed down more for me than Android ever has, over time me. I've reloaded and wiped Windows Phone many times. Posted via the Android Central App
  • I sure hope so, otherwise, what's the point of meaning something new???!!!
  • The key word here is "should". These optimizations rarely make it to enough phones to make a significant difference.
  • Oh good they are finally focusing on battery life with this update, unlike every other Android update ;)
  • Not really experiencing that right now with the Developer Preview 5 on my 6P. It's still good but I'm honestly not noticing any staggering differences between this and Marshmallow, but I could be wrong. I think the only difference I've noticed is standby time while on the move (credits to improved Doze) but even then it's not really a dramatic difference. These improvements tend to be more evident when they come with new hardware rather than necessarily improving older devices.
  • All of this makes me worried about using Tasker.. Blocking apps from getting to system info will kill Tasker and other automation apps. Google should set up a different class of apps that have permission to access and change system parameters. Otherwiswe will have to root the phone to get past Google's attemps to improve battery life.