Xiaomi’s Redmi K90 Ultra is a very on-brand piece of modern phone absurdity: a Snapdragon 8 Elite flagship with an actual built-in cooling fan, a 165Hz AMOLED display, and an 8,550mAh battery. It is available now in China, and the Redmi K90 Ultra spec sheet reads like Xiaomi tried to win every benchmark category at once.
The bigger story is not just raw performance. Xiaomi is leaning hard into the idea that gaming phones no longer need to look like neon-rimmed bricks to be aggressive; they can be thin-ish, premium, and still carry hardware normally reserved for much bulkier devices. That puts the K90 Ultra in the same conversation as other performance-first phones that use vapor chambers, but the fan makes it stand out in a category where most rivals still rely on passive cooling.
Redmi K90 Ultra display and performance specs
The phone uses a 6.83-inch flat AMOLED panel with 1.5K resolution, listed as 2772 x 1280, and a 165Hz refresh rate. Xiaomi says the M10 display material can reach 3,500 nits peak brightness, while touch responsiveness is tuned with a 480Hz multi-finger reporting rate and a 3,500Hz instant touch sampling rate. Translation: it is built for fast visuals and fast thumbs.
Inside, the Snapdragon 8 Elite is paired with up to 16GB of LPDDR5X RAM and 512GB of UFS 4.1 storage. Xiaomi also adds a D2 display chip for AI upscaling and frame interpolation in games, a familiar move in high-end Android flagships that want to squeeze a few more performance bragging rights out of the same silicon.
How Xiaomi is keeping the Redmi K90 Ultra cool
The cooling setup is the headline act. Xiaomi uses an 18.1mm fan that reportedly runs at 32dB, backed by a 6,000mm² vapor chamber to pull heat away from the processor. Plenty of phones use vapor chambers; far fewer are willing to spin a fan in your pocket and call it elegant.
That approach makes sense in context. As flagship chips get faster, sustained performance has become a more useful selling point than peak bursts, especially for gaming and heavy camera processing. ASUS has spent years making that case with its ROG phones, and Xiaomi is clearly happy to borrow the logic without the sci-fi cosplay.
Battery, cameras and durability
The Redmi K90 Ultra’s 8,550mAh battery is the other shocker here, especially alongside 100W wired charging, 22.5W wired reverse charging, and bypass charging. Xiaomi is also claiming IP66, IP68, and IP69 dust and water resistance for the handset, while the cooling fan module itself is rated IPX8 and IPX9.
- Rear camera: 50-megapixel Light Hunter 800 sensor, f/1.68, OIS
- Ultra-wide camera: 8-megapixel
- Front camera: 20-megapixel
- Video: up to 8K at 30fps on the rear camera; 1080p on the front
The rest of the package is very much premium-phone standard issue: dual stereo speakers tuned by Bose, a 3D ultrasonic fingerprint scanner, an X-axis linear motor, Wi-Fi 7, and Bluetooth 5.4. The camera system is sensible rather than flashy, which is probably fine when the rest of the hardware is already trying to pick a fight.
Redmi K90 Ultra price in China
The Redmi K90 Ultra comes in Shadow Black, Space Silver, and Sky Blue. Pricing starts at 2,799 yuan ($420) for the 12GB + 256GB model, and Xiaomi is also offering the 16GB + 256GB version at the same 2,799 yuan ($420) introductory price. The 12GB + 512GB variant costs 3,299 yuan ($495), while the top configuration with 16GB + 512GB is priced at 3,499 yuan ($525).
The obvious question is whether this remains a China-only showpiece or turns into a template Xiaomi reuses elsewhere. A fan, a giant battery and a high-refresh AMOLED are exactly the sort of hardware mix that gets copied fast once a price-sensitive market proves it will buy in. For now, though, the K90 Ultra looks like Xiaomi’s loudest answer yet to the ”all phones are the same” complaint.