How to make 90 hertz on the phone Xiaomi Redmi Note 9

Owners of the popular Redmi Note 9 model often face the desire to squeeze the maximum out of the device, especially when it comes to smooth interface.The regular smartphone supports a screen refresh rate of 60 Hz, which is the standard for the budget segment, but enthusiasts are looking for ways to get around this limitation. Increase the hertz to 90 Hz is theoretically possible through hidden engineering menus or modification of system files, but this requires a deep understanding of the risks.

Before you start any manipulation, you need to clearly understand that overclocking the screen at the software level is an interference with the display module, not intended by the manufacturer. Xiaomi specifically limits the frame rate in this model not only for the sake of energy saving, but also because of the physical characteristics of the matrix.

In this article, we will take a closer look at the available methods for activating increased hertz, ranging from secure developer settings to complex root-right procedures. You will learn what real ways of optimizing are available and why it is impossible to make 90 Hz on standard MIUI firmware for this model with regular means.

Technical limitations of the Redmi Note 9 display

The screen installed in the Redmi Note 9 is based on the IPS-production-matrix BOE Or Tianma, which is physically engineered to operate at 60Hz, which means that the display controller and the panel itself have tight bandwidth limits. When users are looking for a way to make 90 hertz, they often fail to consider that software-based timing changes do not change the physical properties of the crystals.

Xiaomi engineers are setting up controllers to work in the most energy-efficient and safe mode. Trying to make the panel work faster than the specifications can lead to overheating of the plume or degradation of color production. The refresh rate is not just a software setting, it is synchronization of the processor, graphics accelerator and the display itself.

Some people think that 90Hz versions have been sold in some regions, but that's a myth. All global and Chinese versions of the Redmi Note 9 (codename: merlin) have identical hardware limitations. Software "crutches" may create the illusion of smoothness, but the real hertz will remain the same, or the device will go into error mode.

⚠️ Warning: Forced change of screen refresh rate through the engineering menu may result in a black screen or inability to boot the system without resetting settings.

Understanding the hardware is critical before you start any experiment, and if you see a 90Hz choice in the settings, it's probably either a fake program or a modified firmware that's unstable, and real smoothness comes from optimizing animations, not blindly raising numbers.

Checking the current hertzovka and diagnosis

Before making changes, you need to check the current performance of the display. Standard settings MIUI rarely show the exact frequency in real time, so it is better to use specialized utilities, which will help to understand whether the screen is stable at 60 Hz before trying to "overclock".

So, for diagnostics, applications like Device Info HW or Screen Test are great, and they read data directly from the display drivers, and you run that app and you look at the Refresh Rate, and if it's 60 Hz on a steady basis, it's working normally.

• 📱 Download the Device Info app HW Play Market.
• 👁️ Go to the tab "Display" or "Screen".
• 📊 Find the line “Current Refresh Rate” – it should be 60.
• ⚙️ Check if the high performance mode is already included in the battery settings.

It's also worth checking if the developer's hidden features are already activated. Sometimes users accidentally turn on options that affect rendering but don't change the physical hertz. In Settings → About Phone → Tapayem 7 times, the MIUI opens the developer menu.

It's important to distinguish between programmatic frame interpolation and actual refresh rates. Some accelerators are simply duplicating frames, which creates artifacts. Diagnostics gives you an honest picture of how the display module interacts with the system.

Method through CIT Engineering Menu

One of the most common ways to try to change the display settings is by logging into the CIT (Customer Integration Test) menu, which is a hidden part of the system that is designed for factory diagnostics, but it contains deep hardware settings, accessed through a special code in the Phone app.

Enter the code ##6484## or ##4636### into the dialer. If the menu opens, you need to find the partition associated with the display, often called Display or Version Information. However, in most cases, the Redmi Note 9 does not have a direct 90Hz switch, as this option is physically locked at the driver level.

If you're lucky enough to find a Refresh Rate or something like that, don't be too quick to change the values. Write down the initials first. Changing the values in the engineering menu can cause the screen to stop responding to touch or the image to twitch.

In some modified firmware or through ADB-So you can try to send a request to change the display profile, and the command goes something like this: adb shell service call SurfaceFlinger... but the syntax is very dependent on the Android version and the specific kernel patch.

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Before entering the engineering menu, be sure to make a full backup of the data, as resetting settings may be the only way to get your phone back up to work.

Using ADB commands to modify

A more advanced method, often discussed on the 4PDA and XDA forums, involves the use of an ADB (Android Debug Bridge) debugging bridge, which allows you to send system commands directly without going through the GUI. However, for the Redmi Note 9, the effectiveness of this method is limited.

The idea is to change the system properties (props) that render the interface, so you can try changing the DPI density or forcing the frame rate for specific applications, but remember, it doesn't change the physical hertz of the matrix, it just makes the system try to generate more frames.

To work, you will need a computer, a USB cable and an installed ADB driver. After connecting the phone in debugging mode, you can enter a command to check the current properties:

adb shell getprop ro.display.refresh_rate

If the system allows you to change the setting, the setprop command is used, but it only works until you reboot. The permanent effect requires editing the build.prop file, which is impossible without superuser rights (Root). Even with Root rights, changing this parameter to the Redmi Note 9 is often ignored by the kernel.

• 🔌 Connect your smartphone to your PC and enable debugging USB.
• 💻 Open the command line in the folder with ADB.
• 📝 Enter a command to check the supported frequencies.
• 🚫 Do not attempt to enter values manually without checking in the registry.

⚠️ Note: Editing system files through ADB Root-enabled can lead to a "bootloop" (cyclical reboot.

Many YouTube videos show a "successful" 90Hz turn on, but closer inspection turns out that it's either fake or working on tablets with other screens. For Merlin (codenamed Redmi Note 9), the kernel strictly controls frequencies.

Optimizing MIUI for maximum smoothness

Since physical acceleration to 90 Hz on standard hardware is impossible or extremely dangerous, the best way to improve the perception of the interface is competent optimization of MIUI. You can make animations faster, which subjectively increases the "hertz" in the eyes of the user.

There are three important parameters on the developer menu that affect response speed: "Window animation," "Transition animation," and "Duration of animation." They are 1x by default. Changing them to 0.5x will show a significant increase in speed.

It's also worth turning off unnecessary visuals like live wallpaper and heavy widgets. The Helio G85 processor installed in the Redmi Note 9 may not be able to render complex graphics at high frame rates, causing micro-freezes that spoil the experience even at 60Hz.

Another trick is to use themes with optimized graphics, and some Themes themes redraw system elements so that they seem lighter and faster, a software illusion, but it works more effectively than trying to hack a display driver.

Risks and alternative solutions

The main risk of all of the manipulations described above is the instability of the touchscreen, so if the display controller tries to poll the sensor more often than it can, you will get "phantom touches" or complete inoperability of the sensor, and you can only restore the performance by flashing it.

In addition, increasing frame rate increases the load on the GPU and battery. Redmi Note 9 has a battery of 5000 mAh, but with unoptimized operation, it can discharge much faster. Overheating the case is another side effect that can accelerate the wear of the screen adhesive layer.

If you need 90Hz or 120Hz critically, the only safe solution is to change the device. AMOLED-It's a 90Hz and 120Hz screen out of the box, and it's a stable operation, and it's not artifacts.

• 🔋 Increased load wears out the battery faster.
• 🔥 Risk of overheating of the display plume and detachment of the matrix.
• 📉 Possible appearance of broken pixels due to overclocking.
• 🚫 Loss of warranty when a system modification is detected.

Using Custom Kernels is another way, but it requires unlocking the bootloader. On Xiaomi, that means waiting 7 days and completely resetting. Even after that, there’s no guarantee that the kernel will be able to work correctly with your particular matrix at an increased frequency.

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It is safer to use software optimization of animations than to try to physically overclock a screen that is not designed for 90 Hz.

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