I have 3.5 half year old Samsung / Google Galaxy Nexus i9250. The phone has become so slow after that time, that it is simply being unusable. Launching any application, as simple as Gmail or Calendar takes 2-3 seconds, sometimes even five. Pressing Home button needs 4-5 seconds between press and really showing up main screen of my launcher (Nova Prime).

When I purchased this phone, it was simply lightning fast.

I have about 50 applications installed, of which about half is used (15 from time to time and 10 daily) and the other half, never used or used once per 2-3 months. Because I change my attitude very rarely, I have installed these applications in 2012, when I purchased my phone and haven't installed anything or nearly anything ever since that. I would describe this as changing 1-2 application per year.

Because of above, I can hardly accept, that my phone is slow, because I installed too many applications during that 3.5 year period. We can assume, that I'm sitting on the same apps set for past 1-2 years. It is also hard for me to belive, that 50 apps, of which half is nearly never used is enough to visually reduce performance of such phone. Even though it is quite old, its hardware isn't that weak, as I assume.

I of course did a full factory reset once or twice, installing only the same set of applications, as in 2012, after that. It brought little or no help and little or no performance gain. This has actually "killed" me, because I was more than sure, that full factory reset will return this phone to a level of performance and speed close to the days, as it was brand new.

The only theory, that comes to my mind -- though very strange and unbelievable -- is that my battery is old, its performance is far lower than when it was brand new, and thus it powers all hardware with lesser voltage causing its overall performance to degrade.

I know, how stupidly this theory sounds, but it is the only one, I managed to come with, in given situation.

Assuming that number of installed applications and overall usage style of my phone hasn't changed over past 3.5 years of using it, is there any reasonable reason for why it is so extremely slower than it was, when it was brand new?

5 Answers 5


Performance has nothing to do with battery voltage. The reason is that the flash memory is "worn" and therefore slower and less responsive. My Nexus 7 (1st generation) is also very slow now and I have almost no apps on it. You can read more here: Why Android Phones Slow Down Over Time, part "No Solid-State Drive TRIM"

No Solid-State Drive TRIM

The lack of proper TRIM support was the main thing that caused Google’s original Nexus 7 tablet to slow down over time. This was fixed in Android 4.3, which added proper TRIM support. On Nexus devices, updating to Android 4.3 will fix this problem.

If you have an older device that doesn’t have Android 4.3 and has slowed down over time, you can perform TRIM by rooting it and using the LagFix app. This app runs the same fstrim command Android 4.3 runs in the background. TRIM is necessary because of how solid-state drives work — solid-state drives slow down over time because flash memory cells must be cleared before they can be written to again. TRIM preemptively clears cells that contain data from deleted files, ensuring things will be as fast as possible when Android needs to write to those cells in the future.

How to Fix It: Root your device and run LagFix if you’re using an older device. This happens automatically on devices running Android version 4.3 and newer.

  • Why isn't TRIM something that runs automatically? android.stackexchange.com/q/117164/100457
    – mattm
    Commented Sep 11, 2015 at 14:16
  • It seems, that your answer / suggestion stands completely opposite to my situation, as my (all) Samsung Galaxy Nexus has Android 4.3. If Google added TRIM support to that version of Android, then I have it and the lack of it / Flash memory wear-off are not the case. Your answer is good and valuable to others so I voted it up, but I must consider, whether to accept it or not, as your suggestion clearly does not answer the question (no TRIM issue on Android 4.3).
    – trejder
    Commented Sep 11, 2015 at 19:00
  • 1
    @trejder In my experience with a Maguro Galaxy Nexus, TRIM does not run automatically.
    – mattm
    Commented Sep 12, 2015 at 3:02
  • Is there a way to run the trim command without having root access?
    – gian1200
    Commented Sep 20, 2015 at 0:04

You've likely been updating the apps, and they're using more bloated APIs.

I, personally, don't see a reason every app needs to carry Unicode support, for example.

Facebook would be one of the largest offenders. 3 years ago it took 70MB RAM, now 200 so that it, among other snoopy things many apps now do, can carry its own browser to better track you. It doesn't help they split off Facebook Messenger, which also takes 150MB RAM.

'Flash wearing out' is definitely NOT what you're experiencing here.

Additionally, I think Google hasn't bothered optimizing minfree and the OOM manager, or the app lifecycle management. YouI'll have 500MB RAM free on a 2GB RAM phone and you still get home screen redraws all the time, and apps suspend the second you switch to another. Google is lazy and practices 80/20 too much...

Personally I avoid updating apps unless under duress, and use App Quarantine to keep apps locked down when I'm not using them-- for example, Amazon has 5 apps, and they all like to load up running around doing nothing in particular. Keeping them disabled and only unlocking when needed helps with Android's aggressive app suspending.


It's possible that as you use your phone, the apps themselves becomes slower, because it is managing more of your data.

A music app may work blazing fast when you've only got ten music in your library, but then you've collected about a hundred, and the database accesses becomes slightly slower as it's trying to generate the thumbnails or search through the ID3 tag indexes. The music recommendation engine may have worked blazingly fast when it only have to skim through half an hour of listening history, but then it got bogged down once or collected data the years worth of data about the music you skipped often and which ones you have been repeating over and over.

You may have taken pictures with camera app. Originally your gallery contains nothing, and the program can loop through the entire directory fast enough to not matter, but then as you snap more photos, getting a list of all files and looping through them all becomes a lot slower.

You may have added more people in your contacts in chat app. And the chat app have to work through a lot more of the chat history with more contacts and attachment files.

You've used the browsers, and browsers stores browsing history, bookmarks, etc. The size of a browser profile tend to go up over time.

These aren't necessarily solvable by a simple factory reset. If the app had online sync, they would have synced back these extra data that you didn't have back when life was simpler. Likewise with data stored in SD Card/external storage may not get wiped with a factory reset.

  • 1
    As in case of Alex.S' answer, I'm voting up yours, because it can be value to other readers, but I think, I won't accept it, since it is off-topic to my question. I clearly stated, that I did a full factory reset (so I assume, everything, that you're writing, that slows down my phone was cleared to the status of brand new phone) and this hasn't speed up my phone in any noticeable way.
    – trejder
    Commented Sep 11, 2015 at 19:06

Yes, a slightly lower\unstable voltage caused by worn battery can underpower the device SoC affecting performance and stability, not only the autonomy, in the same way can make a torch less bright. I have observed this some years ago when replacing the battery of an old smartphone because of poor autonomy, I have seen also noticeable performance improvements. I have measured the battery output with multimeter and the battery related to poor performance had a lower voltage output (not only 700Mah reduced capacity at full charge compared to the new battery).

However there are also many others reasons that can affect performance, some Apps and services in the years after updates become more heavy in terms of memory(included built in Google services), or the storage nand flash memory can be worn.


Could be due to a couple of reasons:

  1. Flash memory degradation. As you repeatedly write data to your storage, the hardware degrades and increases the chance of hardware failure.

  2. New OS and app updates might not be optimized for your device, and use more resources.

  3. Background processes. Some of the apps you install will open at startup and hog up CPU and RAM. Make sure you clear these.

Are you still dealing with a slow phone?

I'm making an app called Cycle (https://cyclephones.com)

It lets you stream an android emulator from a server to your phone so that you can run any app smoothly. It's great for gaming.

Would love to have you as an early tester if interested :)

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