Licosha — zram is a Linux kernel module for creating a compressed block device in RAM. In short, zram is useful to make use of device RAM for better use and make it more efficient for the device performance especially in devices with low RAM but need extensive multitasking, in this case the Android devices. For more about zram, you can check the Wikipedia about zram.
Usually, we do not need to care whether our Android device are to zram or not to zram, because it is already handled by the settings from the Android device manufacturer that installed the ROM to our device.
But when it comes to custom ROM or Android GSI, zram is one of the extra thing we must take care manually so we can get better performance on our Android device.
We can understand why zram is not enabled by default after installing Android GSI to our device because of how and what for Android GSI is built. But even on custom ROMs I installed on my ASUS Zenfone Live L2 Android phone, I found that zram is not enabled by default.
Without zram being enabled, I can feel reasonable differences on my ASUS Zenfone Live L2 Android phone peformance especially when switching apps where the apps are more often reloaded thus we are spending more time on multitasking.
How to check if our Android device has zram enabled
To check whether our Android device has zram enabled or not, there are lots of apps that can do that actually.
On Play Store, we can use keyword like
disk info to
search apps that has capability to show our Android device hardware
storages, including zram.
Usually in those apps, zram can be notices as
SwapTotal, or simply
zram. If none of those
exists or it is exists but the sum is zero, then zram is not
For example I am using SmartPack-Kernel Manager. On the app's
homepage, I can know whether zram is enabled or not by checking whether
Swap is exist under the
How to enable zram on Android device
There are several ways we can enable zram on our Android device:
- Enabling zram on the
- Setting zram manually using system tweaker app like SmartPack-Kernel Manager.
The first way by editing the
build.prop is easier, I
mostly do it when using a GSI
on my ASUS Zenfone Live L2 Android phone.
However it's different story on custom
ROM. I have installed two custom
ROM on my ASUS Zenfone Live L2
Android phone and editing
build.prop can't make the system
to enable zram.
So for custom ROM, I always using SmartPack-Kernel Manager app to enable zram on the device.
1. Enable zram on Android by editing build.prop
The first way to enable zram on our Android device if it is not
enabled by default is by editing the
build.prop reside in
our Android device
system directory. How it works?
As we know, the
build.prop is a special text file in
Android device that holds various system related default settings that
is usually located on
Edit our Android
build.prop and add the following lines
to the end of the texts:
# ZRAM ro.vendor.qti.config.swap=true ro.vendor.qti.config.zram=true
Don't forget to add an empty line at the end of the build.prop.
2. Enable zram on Android using system tweaker app like SmartPack-Kernel Manager
There are lots of apps that provide capability to tweak our Android
device system performance, including zram. You can find those kind of
apps on Play Store usually under keyword like
The app that I mainly use on my ASUS Zenfone Live L2 Android phone to
enable zram if the
build.prop method is not working is
SmartPack Kernel Manager.
- Android device is rooted.
- SmartPack-Kernel Manager app, download the latest version on its GitHub page.
Steps to enable zram using SmartPack-Kernel Manager
- On the main menu of SmartPack-Kernel Manager, open the sidebar by tapping the hamburger icon on the top left.
- Then on the sidebar menu, scroll down and find
- Now we are in the
Virtual Memorysetting menu of SmartPack-Kernel Manager, scroll down and find the
- First on the bottom, choose the “Z-RAM Algorithm” first. It is usually “lzo” or “lz4” depend on our Android device kernel.
- Next, on the
Disksizeslide under the
Z-RAMsection, adjust it to how much we want our zram size is. Usually the zram size is between 25% to 50% of RAM size. For example if our Android device RAM is 2 GB, then we can set the zram size around 512 MB or 1 GB (1024 MB) (no need to be exact).
- After we set the zram size to our liking, turn on the
Apply on bootand
Virtual memory tunable'sswitch. Next reboot our Android device.
- After the Android device is rebooted, check whether the zram or swap size is present to make sure the zram is enabled.