Hey everyone, Kali here! If you’ve been following the channel, you know we usually dive into installing and reviewing custom ROMs. But for a long time, I’ve wanted to explore the hardware side of things a bit deeper. Today, we are taking a step beyond just changing the OS—we are diving into the world of custom kernels.
Does installing a custom kernel and tweaking it actually make a difference on the Redmi Note 12 4G (Tapas/Topaz)? Let’s find out.
For this experiment, I’m running Pixel OS 16.2. We are going to benchmark the default stock kernel, flash the Zepharo custom kernel, and then push things to the absolute maximum using Franco Kernel Manager (FKM).
The Baseline: Stock Kernel Performance
Before tinkering, we need a baseline. The default kernel that comes packed with this build of Pixel OS (Android 16, version 5.15.148) provides a solid everyday experience.
Running our standard benchmarks on the stock setup, we hit:
- AnTuTu Benchmark: ~430,400
- Geekbench 6: 410 (Single-Core) | 1397 (Multi-Core)
Not bad, but let’s see if we can squeeze out more power.
Crucial Step: ALWAYS Backup Your Boot Image
⚠️ Warning: Before you flash any custom kernel, you must back up your current boot image.
If your current ROM doesn’t support the custom kernel, or if something goes wrong during the flash, you will end up in a bootloop. Having a backup of your boot image in OrangeFox or TWRP recovery means you can easily restore your device without losing all your data. Do this at your own risk!
Flashing Zepharo & Initial Gains
With the backup secured, I booted into OrangeFox recovery and flashed the Zepharo kernel (R8 non-KSU version).
After a successful reboot, I immediately noticed the kernel version had changed to 6.1.271-Zepharo. Without making any additional tweaks—just running the custom kernel as it comes out of the box—we saw a slight bump in performance:
- AnTuTu Benchmark: ~435,224
- Geekbench 6: 433 (Single-Core) | 1399 (Multi-Core)
Unleashing the “Beast” with Franco Kernel Manager
A custom kernel opens the door, but a kernel manager lets you drive. To get real control, I rooted the device using KernelSU Next and installed Franco Kernel Manager (FKM).
Inside FKM, I went straight to the CPU and GPU control panels. I cranked the Maximum CPU Frequency up to 900MHz, set the GPU to maximum, and applied the aggressive “Performance” profiles for the benchmark apps.
Here is what happens when you take the brakes off the Redmi Note 12 4G:
- AnTuTu Benchmark: 461,738
- Geekbench 6: 469 (Single-Core) | 1400+ (Multi-Core)
The Verdict: Is it Worth It?
Going from roughly 430k to over 461k on AnTuTu is a serious jump—roughly a 5% to 10% performance increase. If you are a heavy gamer dealing with frame drops, this extra headroom can give you a noticeably smoother experience.
So, why don’t manufacturers just do this out of the box? Heat and battery life.
When you force the CPU and GPU to run at maximum frequencies, the device generates significantly more heat. To prevent hardware damage, the phone will eventually “throttle” or slow itself down. Furthermore, pushing the processor this hard will drain your battery much faster. Brands lock these frequencies to ensure your phone lasts all day and doesn’t overheat in your pocket.
If you are willing to trade some battery life and manage the thermals for better gaming performance, custom kernels are absolutely worth exploring.
Resources & Download Links
Ready to try it yourself? Here are all the links mentioned in this guide:
- Original Post & Discussions: OG Post Link
- Zepharo Custom Kernel: GitHub Releases
- Root Method: KernelSU-Next