If you have ever noticed that your Android smartphone is overheating while using a simple application or while playing a casual game then this is likely due to the CPU or GPU ramping up to it’s Max clock frequency. Hitting the max clock frequency is generally a good thing when it comes to regular Android smartphone users as it tries to complete the job quickly so it can drop the chip back to an idle state.
This burst performance can be great when the application is not constantly doing something but what if you are playing a mobile game or recording some video then the device is constantly doing something and this can cause it to start heating up while also chewing through your battery life. So in this article, we want to show you how to underclock the CPU and GPU of your Android smartphone or tablet using an application that requires root access. The app that we will be using in this guide is called Ex kernel manager and it is from the well-known Community Developer Flair 2.
It is a Premium app from the Google Play Store but we have seen some free kernel manager applications on the Play Store as well. However, some of the ones that we have used in the past have either stopped working on Modern devices or have disappeared entirely. If you know of a free or open-source kernel manager app that still works then please share it’s name of it in the comments section below. The process that we are going to be showing you in this article should be the same for any kernel Manager application that you can find. The only difference will be that the user interface layout has changed since they should all have a way to set the max clock frequency for both the CPU as well as the GPU of your Android smartphone or tablet.
Steps to underclock the CPU and GPU on Android
If this is the first time you’re opening up the Ex kernel Manager Application then you are first going to be asked to grant root access. Once you have given root access to the application it will then ask you to select a folder on your internal storage that it can have access to. This is so that the application can save backup settings and create backups of your kernel. After you have set all of that up, you can dive into the CPU section of the application by tapping the hamburger menu in the top left corner.
This is where you will want to configure the CPU cores of the device and from here you can change the CPU governor, the minimum, and maximum CPU frequencies for the different clusters, disable specific CPU cores, and more. We want to warn everybody to be careful about which settings you change using this application. For example, if you change the CPU governor to something like power save or conservative then you are likely to notice the poor performance of your device or it dropping drastically in terms of performance. If you change the minimum CPU frequency to something really high then it could quickly overheat the cores and cause the device to stay in a throttled state.
This may be something that you actually want to do but just understand that changing these options without knowing what they can do could have a major impact on the performance and battery life of your Android device. So, to underclock the CPU of your Android smartphone or tablet you have to select the max CPU frequency option and then change it to something that isn’t the largest number on the list. On our sample device, we are able to hit a Max CPU clock frequency of 1785 megahertz but we can drop this to say 1574 megahertz to prevent that CPU frequency from hitting it’s Max clock.
That will reduce the amount of battery that it takes to use that CPU while also reducing the overall heat generation when it is using those CPU cores. Changing this from the largest number on the list to something lower will limit the performance of the device. However, setting this to the lowest number will likely cause the device to slow to a crawl. We only recommend dropping this down a few clocks at a time, for example, going from 1700 to 1500, and then after making the change, test the phone to see if you notice it performing drastically differently. If it slows the phone down too much bring this setting back up a clock or two and then test it again.
You will notice that there could be multiple CPU cluster options there and you will want to change the max CPU frequency for each cluster if you want to underclock those CPU cores as well. After making these changes, you will also want to activate the enable on boot option for those core clusters that you are making the change for. You can do that by tapping the power button next to that option and making it turn Blue.
If you don’t set this option, the application will reset these changes after you reboot the Android device or tablet. After you have underclocked the CPU cores to something you are comfortable with, you can then do the same for the GPU as well. This is done by tapping the hamburger menu icon at the top left and then selecting the graphics option. You will see similar options there including the ability to change the GPU governor, set the minimum and maximum GPU core clocks and more.
If you usually play casual mobile games on your device and you notice that it generates too much heat while you are playing or if you notice that the phone uses a lot of battery life while you are playing this game. Then experiment with reducing the max GPU frequency from something that isn’t the largest number. Our sample device was The Samsung Galaxy S22 and we can hit a Max GPU frequency of 818 megahertz but we have reduced this to 545 megahertz. So, that it doesn’t heat up as much when performing certain tasks.
Both of these changes can save you battery life and reduce the heat generated while using your phone and we encourage you to experiment with them on your Android smartphone or tablet. If you are unsure about what you are changing, just make sure that you don’t activate the enable on boot option with that power icon next to it. If the enable on boot option is not activated then all of the changes that you have made on this application will revert back to their original settings when the device has been restarted.
Changing the kernel options as we have done in this article used to be limited to only those people who have installed a custom kernel on their smartphone or tablet. But some of these kernel manager apps work just fine when using the stock kernel and we can save battery life while also preventing the device from heating up so much by under-clocking the CPU or GPU frequencies.
Experiencing difficulties with your Device, check out our “How To” page on how to resolve some of these issues.