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Reduce Device Lag on Nexus 7 and Others With Seeder Application


Ever wonder what’s up with the lag seen from time to time on your Android device while using certain apps or playing a variety of games? Developer lambgx02 likely cared a bit more than you, as it was bothering him enough to try to find the root cause of the issue so that he could attempt to fix it. He discovered that with a “very limited entropy pool” your device lags, as it waits for the kernel to generate more random data. Confused? Yeah, most of us probably are. In short, he may have found a solution to the problem.

Thanks to an an application and/or .zip file he created called Seeder, your device is able to produce that same high quality random data at much quicker intervals, which results in a reduction in lag.

Here is the technical explanation:

So, I was experiencing significant lag as we all do from time to time, and decided I was going to get to the bottom of it.

After tracing and debugging for hours, I discovered the source of 90% of Android’s lag. In a word, entropy (or lack thereof).

Google’s JVM, like Sun’s, reads from /dev/random. For all random data. Yes, the /dev/random that uses a very limited entropy pool.

Random data is used for all kinds of stuff.. UUID generation, session keys, SSL.. when we run out of entropy, the process blocks. That manifests itself as lag. The process cannot continue until the kernel generates more high quality random data.

So, I cross-compiled rngd, and used it to feed /dev/urandom into /dev/random at 1 second intervals.

Result? I have never used an Android device this fast.

It is literally five times faster in many cases. Chrome, maps, and other heavy applications load in about 1/2 a second, and map tiles populate as fast as I can scroll. Task switching is instantaneous. You know how sometimes when you hit the home button, it takes 5-10 seconds for the home screen to repopulate? Yeah. Blocking on read of /dev/random. Problem solved. But don’t take my word for it .. give it a shot!

In order to give it a shot, you need to have a rooted device. After that, you can either install the .apk file, give it root permissions, and then run it after each reboot. If you want a more permanent solution, there is a .zip file that can be flashed in custom recovery.

I have yet to test it myself, but if you cruise through the XDA threads below, you’ll find nothing but glowing reviews of Seeder. This is definitely not limited to the Nexus 7, either.

Be sure to post your results or thoughts in the comments.

Downloads:  .apk | .zip | Play Store

Via:  XDA [2] [3]

Cheers Teng and Lucas!

  • Tehkharta


  • here’s a true test, HAS ANYONE INSTALLED THIS ON AN OG DROID (A855)?

  • breadable


    I needed an excuse to root again. One day in and the Droid 4 has not had any noticeable lag at all. Maps seems to fly. I’ll do a side by side with the wife’s stock droid 4 tonight

  • Alex Zimmer
  • CPTBeaker

    Android System is reporting high battery usage with this running and it is draining my battery faster than normal.

  • ROB

    What would happen to a non-rooted device?

    • T4rd

      It wouldn’t do anything as it requires root access in order to run it.

  • T4rd

    This doesn’t seem to be doing much for my Note 2. But it wasn’t really lagging much at all before anyways. There’s still the slight delay when waking the phone for some reason though.

    • The screen wake delay has been a problem for a while now… it’s definitely not the seeder app. How is the app working for you now? And how did you root your Note II? I’m supposed to get my Note II replaced already because I cracked the screen and just waiting for the new one to arrive…

      I’ve rooted my GNex before and other phones but I believe there’s not easy method for the Verizon Note II? Or am I wrong?

  • so i usde the flashable .zip method now my only question is, how do i know if its on and does it install an app? or is it just buried system deep that i dont need to worry about it

  • firebird

    This works on my Nexus 7, no lag at all. I would get it sporadically, seems to be totally gone. I am running AOKP MR1 with Franco 37 kernel. Smooth – Woot!!!!!

  • Man I love the android community. Helping the dev out with the play store purchase.

  • Alan Paone

    Not really noticing much on my Gnex or N7. maybe I just live a lagless life already.

    • George Fayad

      Reboot recovery and wipe the cache and dalvik cache and see if that helps.

  • This app is brilliant! This is the app I’ve been looking for to lose that lag!

  • brando56894

    I tried this on my Galaxy Nexus (I had to manually install the files, the APK and ZIP didn’t install them) and it did seem to give it a little more fluidity on JBSourcery 4.1

    • George Fayad

      Also running JBS 4.1 and i just installed the zip through recovery. So far so good. Been messing with the phone for about 6 hours now and i’ve yet to experience any real lag compared to before. For those installing via recovery, be sure to wipe cache and dalvik cache. Install made little difference when i first installed it and didn’t do the wipe. Restored to nandroid backup and re-installed the app then wiped cache and it is like night and day. Hopefully this doesn’t come back to bite me.

      • brando56894

        I installed it on my friend’s Sprint Gnex without telling him (he’s running JBS like us) and wiped cache and dalvik, then gave it back to him and then asked him how it was running and he said “It’s been running pretty fast the past few days” and I asked him if he noticed anything now and he said “not really” then I told him what I did and he said it does feel a little faster, so there really isn’t a way to tell if this is placebo or not. The gains are probably minimal and only really apparent if you’re looking for them, but then again that could just be psychology.

        • George Fayad

          Ah. That I can understand. Mine was noticeably laggy at times after using Chrome for a while with multiple tabs open or after playing games. Now I don’t see any of that lag. If it is in fact a placebo effect, I welcome it!

          • brando56894

            My Gnex definitely does seem more snappy than it usually is, I guess the only way to test it would be to get a timer and time how quickly apps load with the mod and without it. But then again that process isn’t that accurate unless you rig up something code wise because you’d introduce human error.

  • Superdroid

    I thought my Note 2 was fast, now I got to hang on with both hands….. Buy this guy a beer.

  • VZW Gnex, got the play store version. There’s a pretty dramatic improvement in Google Now’s loading time. So far that’s it, but I’ll take it!

  • Finire

    Ok… I am very excited for this. But now that I have a reason to root my infinity, I can’t. Anyone know of a way to root the Transformer Infinity without going all on unlocking the bootloader?

  • illinipoke

    This worked very well on my bionic. I am going to do dirty things to this man.

  • Rodeojones000

    Definitely seeing a pretty major hit with battery life. I think until it’s updated to disable when the screen is off to conserve the battery I won’t be using it. And I’m not quite convinced I’m seeing much of a difference on my N10 as it is.

  • I’m going to use this for a couple days to check battery life.

    I use GSam Battery Monitor to watch what’s going on with my device… because I installed this as an .apk, do you think the app itself will show up in the monitor?

    Or will it show up as something else (e.g., wakelock)? Just curious what others are thinking here. It would be nice to have some data rather than just anecdotes.

  • locofocos

    Also see this extremely relevant post later on, if you want to dig a little deeper. For you other Galaxy Nexus users with the glitch, this post explains how you can do it manually. It looks a little more efficient, since it lets android handle how the random data is filled up. You could just place two lines in your startup file (init.d I believe?) and achieve the same effect. It also gives you a command to monitor how much entropy you have available from terminal. http://forum.xda-developers.com/showpost.php?p=36093065&postcount=254

  • gokusimpson

    Definitely seeing battery drain while using this. Not seeing much of a difference (maybe a little improvement/placebo effect) on my Droid X with Black Ice ICS.

  • rmp20

    Well, this did nothing for me except take me from 22% battery to 10% in about 15 minutes. Running GNex with Shiny 4.2.1. Disabling and going back to how it was (quite good).

  • Paul Messina

    Nexus 4 running CM10.1. Its definitely faster.

  • Rampancy

    Hot damn! IT WORKS! It’s always bugged me that my S3 lock screen turns off and on VERY slowly. Now its INSTANT!

  • sporttster

    Hmmm, using it on my Razr Maxx and not seeing a huge difference in speed yet. Might be unloading it if it keeps up…

  • Jon

    Holy Shnikees!!!!! Incredibly fast on my GNEX!

  • Rodeojones000

    Pro tip: if you install the apk (or use the Play Store link and donate as I did) do not hit the back button after enabling it. You’ll end up turning it off. Rather, turn it on, hit Home, and profit. I’ve chosen to not have it set to enable on boot, but that’s another option built into the app.

  • Twofourturbo

    I haven’t seen this so called “lag” since I obtained by Note 2.. Since then I’ve never looked back..

    • Same! My Gnex would lag quite frequently. Even my Nexus 7 from time to time in Chrome. But not on my Note 2. But I’m trying out this anyway.

      • itznfb

        Am I the only one who has never been able to make my GNex or N7 lag in any way?

        • Mine was perfectly fine literally like the first 7-9months. I’m not sure what happened after, but it pretty bad.

        • Steven Roy

          Don’t run this!
          I never noticed much lag, but I’ll scream if you ask me to go back now.

  • This is sort of a rooting/flashing 101 type question, but I’ve never known the answer.

    In short: If I flash this .zip (as opposed to just installing the .apk), is there a simple way to uninstall it?

    I know that I can make a nandroid pre-flash, then revert to that backup if things go haywire… but I’m thinking there has to be a simpler way to revert back. Is there?

    Thanks, DL community.

    • Danrarbc

      Only if he offers a zip that undoes the change. Otherwise you have to use the other methods. The apk version is the best option IMO until ROMs incorporate this in settings.

    • Rodeojones000

      I’d just go with installing the apk or buy it in the Play store. You can disable or uninstall it quite easily if you’re not happy with the performance.

  • trophynuts

    wait Android has lag? I thought Project Butter was the gift of the Gods that got rid of lag? How can an Android device have lag with dual and quad core processors and up to two gigs of Ram?

    • My point exactly I wonder the same thing,

    • Anything can lag.. that’s like saying your desktop never lags.

  • Steve Edholm

    Seeing some games lag a hair, but apps load very fast. Start up was a lot quicker too

  • joseph johnson

    So far I’m not blown away by it. I’m on a Verizon GNote 2 and I can’t notice a huge difference. The Note 2 is pretty smooth anyways but I’ll test it a little more and see.

    • Danrarbc

      Note 2 is a beast anyway.

    • joseph johnson

      After using it a little longer the input lag that I found with drawing using the S pen is reduced (usually you make a stroke, then half a second later the mark is made. Now it’s almost non-existent), Battery hasn’t been affected. I’ve been using this hack since this morning and haven’t noticed any battery hit yet. Overall, I think it’s worth free or $1.50

  • Detonation

    For those of you thinking this is some magical, genius fix and google needs to use it, it won’t happen. You’re trading security for performance. The mod pollutes secure data with unsecure data that could potentially expose a risk. For the rom/mod community, this isn’t a big deal. But for Google to put this in their OS that is used by hundreds of millions of people, that is a big deal.

    • EvanTheGamer

      This is your third post about the same thing. Okay, we get it. Thanks.

      Moving on…

      • Heaven forbid someone be worried about security!

        • Steven Roy

          I should certainly hope so!
          First, it’s Heaven! What good is Heaven if there is something to worry about?
          Second, it’s Heaven! Security shouldn’t be an issue.

          • …how far is heaven? and IIIIIIIIIIIIIIIII-

    • Danrarbc

      It’d probably be possible to fix it with the way /dev/random is handled natively, it’s apparent it’s an issue so it really does need a fix. Newer ARM cores are bulking up on instructions too, adding more specific ones that help with cryptography.

    • Rodeojones000

      Are you developing some sort of rival app designed to do the same thing and therefore are trying to steer people aware from this? Or do you enjoy being the proverbial turd in the punch bowl? Everything we do with our devices from the moment we unlock and root them has a risk involved. But in this case it appears to be worth the risk. Thank you for the initial post bringing to light potential risks. You can stop repeating yourself now.

    • bakdroid

      Really?!? Oh my…someone should stop this!! Everyone should know how bad this is!! Oh the humanity!! *sarcasm*

  • Rodeojones000

    If this gets rid of the lag one experiences when using Chrome (even on my N10) I’ll gladly pay $10 for it.

  • Its about time.. this guy needs to get picked up by Google.. I have had to wipe my Nexus 7 every 45 days or so without fail..

    • Really? I used my Nexus 7 for 4 months straight without performance degradation :/

      • renGek

        I’m also curious about these N7 lags because I have had mine since it was released in July and I have yet to experience lag. I’m on the thing for several hours daily. I have traveled all over the country with it and I use the heck out of it. So I’m wondering why I keep hearing 2 camps, one with lag and one with none at all seemingly nothing in between.

        • Rodeojones000

          The problem is what is often referred to has “lag” is quite subjective. Lag for one person might seem blazing fast to another. It’s all a matter of perspective.

  • Sirx

    Dear lambgx02,

    If this fixes the horrible experience I’ve been having on my Prime Infinity, then I’ll look for you.

    I WILL find you.

    And I will kiss you.

    But, you know, in a totally manly way……gee, that got awkward.

    • It’s not gay if you don’t use tongue?

      • y0_momma

        or close your eyes.

        • DroidGuy

          Or Tea Bagging lmao

      • Tony Allen

        Dude, everyone knows all is not gay, as long as balls don’t touch.

    • Ramona M. Geter

      If you think Stephen`s story is super,, 2 weeks ago my cousins
      girlfriend basically also earnt $8092 sitting there twenty hours a week
      from home and their friend’s step-mother`s neighbour done this for 3
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    • Randy

      There’s no such thing as a “Prime Infinity” just so you know. There’s the Transformer Prime (TF201) and Transformer Infinity (TF700).

    • It’s not gay if the balls don’t touch.

  • PhoenixPath

    Interesting….a few minutes of testing and I have to admit, my curiosity is piqued. It will take a bit of use (read: a few days), but initial impression is mostly positive.

    It seems more snappy, but I am not sure if it’s a “speed increase” or an “animation reduction”. Scrolling seems fluid though, so I’m leaning towards “speed increase”.

    Definitely something to look into.

    • Placebo?

      • PhoenixPath

        Not entirely sure yet. I’ll keep it going for a bit and remove it, and probably do it all over again just to be sure.

        Note: This is on an already optimized AOKP on a VZW Galaxy Nexus. I’m using Steve Spear’s PUB build for Toro dated Dec. 25th. He did quite a bit of optimizing on this build as I understand it, so anything I may or may not be experiencing will likely vary from most others…

        Steve’s builds can be found on Androtransfer under his name.

        • I wasn’t trying to be critical. I have it installed as well. I think I notice a little difference as well, but I could be imagining it.

          • PhoenixPath

            Didn’t take it as such, just clarifying my process (as much for myself as for anyone else…).

    • Rodeojones000

      I, too “think” I see a difference but I can’t help but wonder if some sort of placebo effect is going on here. Apps seem to load faster, but I’m using it on my 9-day-old Nexus 10 which was already quite snappy to begin with.

      • Nicholas The Intelligent

        I have a Droid RAZR maxx, and I can definitely see the improvement. I generally see lag in Dead Space, and other heavy games. Even the ad service in Angry Birds Star Wars causes hiccups and funky transitions. That is all MUCH smoother now. I have notices a nimt of lag here nad there, but nothing like I am used to.

        With a beast like the Nexus 10, I should hope it doesn’t have any lag to begin with.

  • Seth Merritt

    Every time I go back into the app on my gnex, it says its off. Not sure what’s going on there.

    • Jonathan Isenberg

      Not that on my Nexus 7 too. Is this by design?

      Also, great find. Paid for the app without a second thought.

    • I’m seeing it say it is disabled/off everytime I open the app on my Nook Color.

    • Use home button instead of back after turning it on. It will stay on that way.

    • BroRob

      Same was happening to me. Next time go in the app, turn it on and then use home button to exit. Go back in and it will show on.

      • Jonathan Isenberg

        That’s because the home button just takes you to the home screen, suspending the app, but not closing it.

    • Hm same here for some reason. Rooted and everything. Could be a UI bug.

    • I think I needed to be a little more patient. I turned it on on my Gnex and waited a few seconds, let Superuser do its thing, and then went back home. It’s stays on now 🙂

    • CoCoCalypso

      Yeah same here… I havnt really noticed a difference in speed either, as everyone else has described.

      Running AOKP on toro

    • According to the XDA Forum, the “Always off” bug after returning to the app is known. I ran the following command in a terminal emulator to verify that it was still running, even though the UI in the app said it was off:

      ps | grep rngd

      You will see something like /data/com.yadda.yadda.yadda/rngd

      (From: http://forum.xda-developers.com/showpost.php?p=36234571&postcount=444)

    • brando56894

      I had to manually install the files because the app didn’t install them on my Gnex. But I read later that the app apparently “doesn’t touch /system” so I’m not really sure how it works. Also the Zip didn’t install anything either, but then again I later read that you have to do su;seeder after you flash it to get it to work. Placing the files manually was a surefire way to make sure that they worked.

  • Cool idea, but that’s going to destroy the battery waking up every 1s (or any interval). Needs to be modified to only run when the screen is on, since responsiveness when the screen is off is not important.

    • C-Law

      I agree. I can’t see the need for this while screen is off. I saw him mention he can change this though so I’ll give it a try once he does.

    • PhoenixPath

      Depends on how quickly the device can resume “deep sleep”….

    • Yeah, I’m going to see how it affects my battery life as well. That will be easy to notice with a Galaxy Nexus LTE >.<

      I already can barely go a 5 to 7 hour day without it dying already (with minimal use).

      • Steve Jobs

        Completely kills the battery on my Nexus LTE, 60% to 40% in less than 30 minutes, screen off.

        • My GNex (toro) seems to be on par with its usual battery life…. stock battery, SlimBean 3.0, LeanKernel, a number of background apps. I’m at 85% after an hour on battery with 25 min screen time. Haven’t gotten a chance to do a full day test yet though.

          (4G radio is OFF btw)

  • robertoelbueno

    Absolutely flying! Night and day. Gnex running CM 10.1

  • ragnarok180

    It actually works. I’m browsing with Chrome and my Gnexus is flying. I’ll monitor battery life throughout the day as it is a concern. The dev was nice enough to include a toggle switch on the app though…

  • Cody Stamps

    Wow this really kicked my phone into high gear. I am going to root my Nexus 7 now just for this. And to anyone wanting to get this, use the Play Store link. Developers like this should get paid/donations for their efforts.

    • ragnarok180

      Went with the Play link without a second doubt.

  • EvanTheGamer

    YES! I’ve honestly been wondering this myself as of late while using my 16GB N7. Whenever I use Gmail, Chrome, or some other heavy usage apps, the app seems like it’s going to FC, but then after a few seconds, it finally starts working again. I wasn’t entirely sure whether the lag or possible FC is caused by the fact that I’m running out of storage, or something else entirely.

    I’ll give this solution a shot and hopefully it’ll be just what the doctor ordered! Thanks for posting, D-L!

  • Wait, it’s $1.49 on the play store, but the apk and zip files are free?

    • gokusimpson

      Maybe the play store one is more like a donation? If it is as good as they say, I’d happily donate!

    • Teng Taing

      donation to the dev.

    • Dan Treacy

      Devs are not allowed to ask for money on XDA.

      • Right, I get it. But why offer it outside the play store at all? I’m just curious.

        • Because the dev is awesome and gives us the option of paying if we want to instead of demanding it, which he is absolutely entitled to do.

        • renGek

          The freebie should be for you to try. He probably doesn’t want a free one on play because nobody would donate to the pay one. since only a small group of enthusiasts would know about the free apk it ends up being a good pool of users to test on. I say try it out and if you like it pay the man so he can make more awesome stuff.

        • r0lct

          In order to post about an app in XDA he needs to offer on the site for free.

          • Joshua Rossi

            $1.49 is nothing! We all spend more than that on mid-day snacks that make us fat.

          • r0lct

            Agreed. I’ve bought many donate apps and made direct PayPal donations when no paid option existed.

        • y0_momma

          Think of it as a “try before you buy” feature.

          • Bruce Lee

            Most people think of it as a “why buy? If you can try….forever”

    • Seth Merritt


    • keinescheisse

      Why not. Pay for convenience every day.

    • PhoenixPath

      In his OP on XDA:

      For those who want Google Play’s auto-update feature. (I assume rather than checking the XDA page for updates)

    • sc4fpse

      Some devs that are XDA community members release an application for free to XDA members (as a community gift/thank-you), and put a paid version on Google Play for non-XDA members, or for those who wish to purchase it as a donation.

    • Steven Roy

      You can think of it as a donation if you like, but it also allows the app to be updated automatically if needs be.

  • Detonation

    Might want to mention this in the OP (taken from xda thread):


    There is a (theoretical) security risk, in that seeding /dev/random with /dev/urandom decreases the quality of the random data. In practice, the odds of this being cryptographically exploited are far lower than the odds of someone attacking the OS itself (a much simpler challenge).

    This may adversely affect battery life, since it wakes every second. It does not hold a wakelock, so it shouldn’t have a big impact, but let me know if you think it’s causing problems. I can add a blocking read to the code so that it only executes while the screen is on. On the other hand, many of us attribute lag to lacking CPU power. Since this hack eliminates almost all lag, there is less of a need to overclock, potentially reducing battery consumption.

  • Spike760

    Does it affect battery life at all?

    • Detonation

      yes. see xda thread:

      “This may adversely affect battery life, since it wakes every second. It does not hold a wakelock, so it shouldn’t have a big impact, but let me know if you think it’s causing problems. I can add a blocking read to the code so that it only executes while the screen is on. On the other hand, many of us attribute lag to lacking CPU power. Since this hack eliminates almost all lag, there is less of a need to overclock, potentially reducing battery consumption.”

  • Detonation

    Giving the benefit of doubt to Google that they were aware of this, perhaps there is some side effect or reason why they chose to not do this.

    • vitriolix

      1. security 2. battery.

      Solving these sorts of systemic issues is never, ever a simple fix

    • KleenDroid

      While I get what you mean, there will always be improvements.

  • Oscar De La Rosa

    Someone start a petition to get this guy hired at google!

  • Brent Cooper

    Google, please hire this guy!

  • That’s why I use my iPad mini more than I use my nexus 7 because of the lag, I just don’t understand the use of all the processor power the nexus 7 have but yet it still lag.

    • Danrarbc

      Tegra 3 isn’t actually all that good for anything other than games. Even then it’s not the best, just better than many.

  • Detonation

    Uninstalling the app and rebooting (or just not launching it after boot) will put things back to default, right? I want to try it on my Razr Maxx but I’m on JB so there’s no safety net right now.

  • Danrarbc

    Google, hire this guy!

    • WAldenIV

      Let’s see the impact on battery life first.

      • Danrarbc

        Tweaking the scheduling, fixing wakelock and the size of the pool to optimize battery life seems like it should be able alleviate any battery life decrease – the CPU having to ramp up to fill /dev/random as it is now isn’t good for battery life either.

      • michael arazan

        If you do lose battery life, minimally probably, it’s worth it to have speedier apps and less lag, I’d think the buggy lag though would eat more battery life up with the stuttering of trying to keep up

    • PuzzleShot

      Wouldn’t it be easier if he just submitted a patch to AOSP instead?

    • Detonation

      Google is probably already aware of this and hasn’t made these changes on purpose due to the security risks it adds.

      • NexusMan

        What are the security risks?

        • Mack

          From XDA:

          “There is a (theoretical) security risk, in that seeding /dev/random with /dev/urandom decreases the quality of the random data. In practice, the odds of this being cryptographically exploited are far lower than the odds of someone attacking the OS itself (a much simpler challenge).”

  • ohsosick. Hey Pete…wanna bake that into the next BB build? …kthanks 🙂

    Oh how I love the openness of Android. And by discovering/fixing this, I imagine the next official version of Android will have it as well! I don’t think this sort of thing happens on the “other side of the fence” when there are issues 🙂

    • It seems that Pete is sort of done doing the ROM thing for now.

    • Rick Lopez

      I though Pete is no longer making BB builds? From what I read through the INTERNETS he has alot on his plate, new car, girlfriend,job,school..

      CM team please include this on your next build.

    • Rodeojones000

      Time to look into a new ROM. Pete’s pretty much given up developing for Android.

      • ceejw

        True. I moved to MMuzyRom and I’m pretty happy. So far it seems to be pretty much what BB 4.2.1 would have been

      • AnotherAndroidKid

        I went to Shiny. It is basically stock and the dev has been very accessible on rootzwiki.

  • Keith Sumner

    Someone needs to get this info to Google so they can implement this!

  • Murphy

    My Nexus 7 just said “What lag?…”

    • Nickan Fayyazi

      Oh, how I envy you. My N7 used to be super smooth, but everything went downhill when I updated to 4.2.