Why Android’s UI Isn’t As “Smooth” As iOS

Android vs iPhone

A few Google+ posts by a Google Engineer and by a former Google intern and soon-to-be Microsoft intern correct poor “facts” and shed some light on why Android’s user interface isn’t as smooth as iOS‘s. The reason may not be what you think it is.

Dianne Hackborn, an engineer at Google, hopped on Google Plus to set straight some of the misinformation that’s been floating around about Android.

She says that some form of hardware acceleration has always been utilized by Android, since Android 1.0. This includes window compositing, menu transitions and pop-ups, the notification bar’s animation, and some others.

However, prior to Android 3.0 – “Honeycomb,” the tablet-targeted OS – drawing inside of a window was usually software based, and hardware acceleration wasn’t needed to get 60fps frame rates. Honeycomb changed things to add more prevalent hardware acceleration options to developers. Android’s newest version, 4.0 or “Ice Cream Sandwich,” hasn’t made drastic changes except that hardware acceleration is on by default now.

A key fact of the debate of Android performance has been the use of hardware acceleration. Hackborn describes why using it isn’t really as ideal as people think it is:

Hardware accelerated drawing is not all full of win. For example on the PVR drivers of devices like the Nexus S and Galaxy Nexus, simply starting to use OpenGL in a process eats about 8MB of RAM. Given that our process overhead is about 2MB, this is pretty huge. That RAM takes away from other things, such as the number of background processes that can be kept running, potentially slowing down things like app switching.

Overall, Hackborn sets quite a few facts straight in her long post. Be sure to check it out.

Andrew Munn, a former Google intern and soon-to-be Microsoft intern, took Hackborn’s facts and aimed to explain why Android doesn’t provide as smooth of a user interface as iOS, WebOS, or even Windows Phone 7.

RedmondPie summarizes Munn pretty well:

UI rendering processes in iOS occur with dedicated threads with real-time priority whereas on Android, UI rendering processes occur along with the main thread with normal priority. Whenever an iOS devices detects touch, it stops other processes and focuses all attention to rendering the UI. Android devices don’t do this, instead general processing and UI rendering occurs concurrently which results in choppy UI.

Munn states in his disclaimer that he has tried to do as much research as he can, but he did not work on the Android framework, nor has he gone through Android’s rendering source code.

If you’re more interested, be sure to check out the original posts linked below. They contain quite a bit of valuable information, especially considering that Android’s lack of smoothness is one of its biggest criticisms.

[via Dianne Hackborn on G+, Andrew Munn on G+, Phandroid, RedmondPie]

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  • Mykel


  • iRSX

    Just tried out a whole slew of tablets while I was at Staples today (girlfriend needed a new calculator) and OMFG all the Android tablets were LAGGGGGGGGGGYYYYYY. WTF? There was no iPad 2 there but it doesn’t matter because I’ve used that enough to know what it’s like. There WAS a BlackBerry Playbook there and let me tell you guys: go try the thing out. It is absolutely smooth as butter. Comparable to iPad in terms of UI fluidity. I also love the card system that it stole from WebOS. Too bad the rest of the OS isn’t so great…*sigh*.

  • Ed

    Android UI is smooth like Keith Stone

  • Jorge toro

    Android sucks iOS’s dick… In slowmo by the looks of it. Lol

  • OGT

    What about Flash Player? 1+Android 1-iOS

    • javier

      What about it, Adobe said it’s dead, at least the mobile version 😛

      • OGT

        Android Mobile support Flash Player…!

        • mhmm

          not for long

        • Xavier

          Flash is so Dinosaur age just like your droid lol HTML5 is the future

          • OGT

            I have an iPhone u idiot..!

        • SilentPhart

          Wow there are still phandroid idiots that think Flash is a “one up” for Droid? So you read news whatsoever? Are you aware that Adobe (maker of Flash in case you’re too clueless to know) is getting rid of mobile Flash because even they admit it’s crap?

          Droid users, in general, are the least informed, most ignorant smart phone owners by far. You can find proof if it everyday in the comments section of articles like this.

          • ctrev08

            Can u watch tnt.com on ur iphone out of the box. no +1 for android. html5 may be the furture but one of the main reasons i use my thrill over my iphone 4 is flash. and a bigger screen. faster emulators. and there is nothing like playing mario kart 64 in 3d

          • Kenn Adams

            @SilentPhart: I’m sure 100% of Android users visit an iphone hacking site to show their lack of smarts to support your comment. Get real.

            Nothing wrong with being a fan of something great like iPhone and iPad. But I think a lot (not all) come here to jailbreak because iOS is lacking.

            Yes, Flash is dying. But until it is dead, I will have to pull out my Android to view many sites that my iPad can’t view. So yes, +1 for Flash. Don’t pretend its not a shortcoming for iOS all of a sudden because of Adobe’s very recent announcement. Hundreds of sites aren’t going to covert their flash pages overnight just because of that.

            You can be a fan of your phone because you obviously spent a lot of money on a very nice device. But don’t be ignorant.

          • Agree

            I completely agree. Some replies are just a tad bit ignorant and there is no place for them here.

  • Steve

    I carry both iPhone 4s and the galaxys2… That being said I think they both run smooth.i can’t speak for the tablets.the iphone makes music and video transfer easy with iTunes.if android had some sort of iTunes like program I probably wouldn’t of got a another iPhone.i love apple products,I have apple tv,MacBook pro,iPad,and iPhone 4s. But I like having flash support on my galaxy s2 and the bigger screen.it runs smooth and I see no difference between the two phones.the world of android is pretty cool and I’m glad I left iPhone for a bit to get check it out… Now I gotta carry both cause i love both.

    • Rip

      get doubletwist from android market. it’s free

  • shane blyth

    Whats the spec on a Galaxy S2? its a dual core 1.2 or 1.5 ? cant remember but the iPhone 4S is only dual core 800mhz CPU and iPhone 4 single core . So they have to put way more grunt to get a similar result. Pity really imaging if / when it gets a similar system the Androids would really be super fast n smooth

    • Nosferatu

      Galaxy S2 is a dual core 1.2Ghz with 1GB RAM.

      I just recently rooted it (jailbroke it) just for the heck of it. I noticed most of the time the S2 runs around 500Mhz it only ramps up the CPU speed when it needs it. It’s silky smooth from the factory but it got even more so after I installed a new ROM (software). Absolutely zero lag.

      Can’t speak for the tablets as I’ve never used one before (and don’t see the need for one personally).

  • Ashzzsss

    If you guys were to stop fighting over what os is better you would of read the last guys quote on why iOS is so silky smooth.

    “Whenever an iOS devices detects touch, it stops other processes and focuses all attention to rendering the UI.”

    Hey i own an iPhone 4s but it would be nice to have a silky smooth android tablet for reading comics =/

  • fas

    iOS for the win always.

  • Paul

    Good post on why iOS is silky smooth among other features Apple as come up with. Other OS’s should look into maybe learning from that if possible. Flash is going to die sooner or later but we should understand Flash is still big on the net now. I need flash to get the best of the Internet. If you can Get flash on your toy get it. I wish my iPhone used flash now. Bought a Playbook for Full 11.2 Flash (no lite stuff). Until most websites really start to impl

  • Paul

    ement HTML5, get me a flash player capable device please. Apple great at being easy and SICK app store. Awesome job there. Just flash away from being perfect. Guess perfect would be too much.

  • Pacomac

    This article is incorrect on many levels. The iPhone does not update the display in real-time background threads. In fact all UI updates have to be done on the main thread, so her argument doesn’t hold water!

  • Pacomac

    Also on the iPhone touch events are low priority, and if foreground processes are consuming too much CPU touch processes do not occur, contrary to what is said in this article.

  • Both operating systems are very similar
    It all comes down to personal preference

  • affinity

    First UI: I think android will get to a point where UI is as smooth as iOS, however it will probably be pushed from a hardware perspective than a software one.

    Second Flash: Give me a good flash player on the desktop, then we can talk about getting a good one on mobile devices. Adobe should just Open Source it and i bet within a year there would be a good one out there.