I own a LG-D855 which I bought refurbished running the bundled modified version of Android that LG provide.

After a few weeks I installed Cyanogenmod 12.1 and since then I've been updating weekly.

When I turn the phone on for the first time it runs very quickly. However after using the phone with a handful of apps for 15 or 30 minutes the whole phone slows down to a crawl.

I've installed an app which stops as many background processes as it can. After running this the phone speeds up again, but soon returns to it's previous state.

I bought an LG G3 as it rated very highly on lists of the best Android phones to buy.

Why am I having these problems? Are these common issues with the LG G3? What can I do to allow my phone to run more quickly?

  • D855 is my phone. And I can guarentee you it is international variant of G3.
    – SarpSTA
    Dec 2, 2015 at 17:59

3 Answers 3


First of all, G2 should be D80X, the 85X is the G3 line.

I am an owner of G2 on CM12.1, and I never had any problems regarding speed. It was always fluent without any hiccups.

  • You can try to hibernate apps using Greenify.
  • You can rollback to a previous ROM version/nightly because the current may have bugs
  • Apps that slow down the phone usually also drain the battery more, look for the apps that use the most battery life and uninstall them
  • You can swipe apps from the recents when you are done using them
  • Use some tools to help you out like Xposed, CPU Spy and similar to find and eliminate the problem

In the end, there could be also the case that your CPU is maybe downclocked, or some other hardware issue. Anyways, the G2 on CM12.1 should give you excellent overall experiance.


Try wiping dalvik cache if problem still persists try checking your cpu through any cpu app (I prefer setcpu) check your cpu rate if it's underclocked try increasing it carefully (as it may overheat your cpu)


In the end I:

  • Performed a factory wipe
  • Install Cyanogenmod 13

Since then the phone has been running silky smooth.

It's possible that cleaning the Dalvik may sorted it, however I went for a more extreme and complete approach which ultimately worked out. The downside being I needed to setup my phone again after the fresh install.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .