You might have seen people talking about custom kernels on Android. You might have heard about the crazy benefits of custom kernels alongside custom ROMs. Being curious and searching for it online, you ended up on this page.
I can understand that. I’ve been a custom ROM user for more than 5 years. With that in mind, I started writing this article explaining what a custom kernel is and all its benefits as well as shortcomings and risks. I will tell you everything from a user’s perspective and my experience with using custom kernels.
What is Kernel in Android?
A kernel is a core component of an Operating system and primarily acts as a mediator between hardware and software, particularly the operating system. The kernel determines how the hardware will be used for specific tasks. Such as we use our phones for various tasks such as internet browsing, calling, taking photos and videos, playing games, and so on.
Different types of tasks require specific CPU frequency or calculation per second for better understanding. The kernel controls how much calculation the processor will do per second to complete a specific task. While gaming, the kernel increases the frequency of the CPU and GPU so that it can calculate a lot of data. This also increases power consumption. On the other hand, the kernel limits the frequencies when normal tasks are being done such as using social media apps. This helps lower power consumption and increase the battery life of the device.
Now that you understand who whats kernel and how they work, let’s understand what a custom kernel is all about.
What’s a custom kernel on Android?
A custom kernel is the modified version of the stock kernel that comes with the device. Sometimes OEMs make the kernel of their specific devices Open-Source so that the community can play with it. Some enthusiast developers or students try to modify the kernel and optimize it for better performance and efficiency.
Xiaomi devices have been very popular for developing custom ROMs and custom Kernels for them. Because Xiaomi releases the kernel source of almost all of their devices. This helps developers practice their expertise in Linux kernel development.
For example, Poco F3/ Mi 11X/ Redmi K40 has a lot of custom kernel options to choose from. Not only custom kernels, we have a lot of custom ROM options too for the Poco F3.
What’s the point of a custom kernel?
Every smartphone manufacturer tries to develop a good kernel for their devices. But it requires a lot of time and testing. As the profit margin for smartphones of budget to mid-range price points is very low, they can’t afford to invest that time and resources in them. They make a usable kernel and ship them with those phones. That’s why sometimes you hear smartphones being dead after software updates. OEMs can’t do enough testing before releasing an update to budget smartphones.
If the device is value for the money and gets popular, third-party developers tend to buy it and start developing kernels for the device. This way they can practice their knowledge on kernel development. This also helps the community by offering better-performing kernels for their phones.
Benefits of using custom kernels
Custom kernels can improve the device performance by quite a margin than the stock Kernels. OEMs sometimes limit the true potential of the SOC to avoid overheating. For gamers, this is not ideal. A custom kernel with overclocked frequencies can improve the gaming performance. Not only overclocking CPU and GPU, controlling how the RAM will be used plays a vital role in gaming.
Older devices with powerful hardware sometimes struggle to provide better gaming performance because of outdated GPU drivers. This can be easily fixed by using the latest GPU drivers. You can get the same level of graphics quality as a Snapdragon 8 Gen 3 device in a device with Snapdragon 845 or sometimes lower.
Higher performance always results in higher power consumption and leads the phone to overheat. The overheating while gaming can be reduced by undervolting the GPU. This is done by lowering the voltage level for each frequency by editing the voltage and frequency table. If you are rooted and have a device with a snapdragon chipset, you can use the Konabase app to perform undervolting as well as overclocking on your device.
Undervolting is a proven technique to reduce power consumption and improve thermal performance at the same time. A custom kernel with undervolted frequencies can improve power efficiency and reduce temperature rise while gaming.
That being said, updated custom Kernels come with the latest security enhancements and optimizations which makes the device better compatible with the latest apps and updates. Skilled developers make a huge amount of underlying improvements to a custom kernel that shines when you use the device as a daily driver.
Pros of using a custom kernel
- Overclocking & tuned RAM for performance gains, plus the latest drivers for older devices.
- Undervolt GPU to reduce power draw & overheating while gaming.
- Undervolt & optimized tweaks for improved power efficiency.
- Latest security patches & optimizations for better app compatibility & daily use.
- Go beyond OEM limitations for more power & customization.
Shortcomings of using a custom kernel
The first and foremost downside of using a custom kernel is that you need to unlock the bootloader of your phone. Some OEMs don’t allow unlocking the bootloader and do modifications to your device. In that case, you will lose the official warranty and support from the manufacturer.
Custom kernels sometimes come with cons. A poorly built kernel can greatly worsen the user experience and the performance of a phone. Sometimes custom kernels can cause battery drain, performance drops, break hardware features, or even soft-brick the device. So you have to be careful choosing custom kernels for your device.
Flashing kernels made for different devices can corrupt the storage and cause hard bricks to your device.
Cons of using a custom kernel
- Warranty void: unlocking the bootloader removes official support.
- Performance risks: poorly built kernels can harm the battery, and features, or brick the device.
- Device incompatibility: the wrong kernel can corrupt storage and permanently damage the device.
How to install a custom kernel on your Android phone
First, you have to find out if your device has a community for custom ROMs. For example, we will be searching for custom ROMs and kernels for Redmi Note 10 Pro. For this, search on XDA Forum if there’s any community for your device. Then enter the community and go to the development tab. You will find custom kernels as well as custom roms there.
Another great place to search for custom ROMs and kernels for any Android device is Telegram. If you want to enter the custom roms world you should have a telegram account. Search on Telegram with your device name. If you find channels or groups for your device, join there and search for custom ROMs.
Besides custom kernels, will also find custom ROMs and guides to unlock the bootloader of your device.
Reasons why you should start using custom kernels
- Case 1: If you are a gamer and not satisfied with the performance of your device, you should try custom kernels. Otherwise, it’s not recommended.
- Case 2: If you aren’t satisfied with the battery backup of your phone and think it can be improved, then you should try too.
The Final Verdict
A custom ROM can greatly improve the performance of your device and improve the battery backup too. So it still makes sense to use custom kernels in 2024. Just be careful of choosing the right kernel and you should be rocking.
Rashidul Hasan, the founder and CEO of AndroidStory, is very passionate about technology.
