Xiaomi has pushed the Redmi K90 Ultra into a rare category for mainstream phones by adding a built-in cooling fan inside the body. The move is aimed squarely at long gaming sessions, where heat often becomes the first limit rather than raw performance.
The phone expands the Redmi K90 series and arrives as the successor to the Redmi K80 Ultra, which appeared in June 2025. With a larger battery, a high-refresh AMOLED panel, and Snapdragon 8 Elite power, Xiaomi is positioning it as one of the company’s most performance-focused devices.
Cooling system built for heavy gaming
The most unusual feature is the internal fan, which Xiaomi says measures 18.1 mm and reaches 32 dB at maximum speed. The company claims it can lower temperatures by up to 10 degrees Celsius during demanding use.
To make that design practical, Xiaomi gave the cooling fan IPX8 and IPX9 protection. That means the system is still rated to handle high-temperature water spray, despite being part of the phone’s active thermal setup.
Large AMOLED display with 165Hz refresh rate
On the front, the Redmi K90 Ultra uses a 6.83-inch AMOLED M10 panel with a 1280 x 2772 pixel, or 1.5K, resolution. It also supports a 165Hz refresh rate and a peak brightness of 3,500 nits.
Xiaomi also places the fingerprint scanner under the display and includes a 20MP selfie camera in a punch hole cutout. That combination keeps the front clean while matching the phone’s gaming-first profile.
Flagship chipset, gaming chip, and fast memory
For performance, the Redmi K90 Ultra is powered by the Snapdragon 8 Elite. Xiaomi pairs it with a D2 gaming chip to push gameplay output to 1.5K resolution and 165 fps.
The device uses LPDDR5X Ultra RAM and UFS 4.1 storage. Available memory options include 12/256GB, 16/256GB, 12/512GB, and 16/512GB.
Battery capacity takes the lead
The Redmi K90 Ultra carries an 8,550 mAh battery, one of the phone’s biggest headline specs. Charging is handled by 100W wired fast charging through USB Type C, along with 22.5W reverse wired charging.
Xiaomi also includes bypass charging, a feature commonly associated with gaming phones. It helps reduce heat buildup when the handset is used while still connected to a charger.
Camera module, durability, and software
At the back, the fan sits inside a rectangular module that also houses an LED light and two vertically aligned cameras. The main camera uses a 50MP Light Fusion 800 sensor with an f/1.68 aperture and OIS, while the ultrawide camera is an 8MP unit with an f/2.2 aperture.
Even with the cooling opening, the Redmi K90 Ultra still carries IP66, IP68, and IP69 ratings. In practical terms, that gives it protection against dust, immersion in water, and strong high-temperature water jets.
Xiaomi rounds out the package with stereo speakers, an infrared transmitter, and HyperOS 3 based on Android 16. Color options include shadow black, space silver, and sky blue.
Price and market availability
The 12/256GB version is priced at 2,999 yuan, or around Rp7.9 million. Other variants are listed at 3,199 yuan for 16/256GB, 3,499 yuan for 12/512GB, and 3,699 yuan for 16/512GB.
Xiaomi has not confirmed any international release for the Redmi K90 Ultra so far. For now, the device remains a China launch that will mainly interest gaming-phone buyers and users looking for unusually strong thermal management.
