Xiaomi has launched the Redmi K90 Ultra in China, and it is not trying to be subtle. The Redmi K90 Ultra pairs a Snapdragon 8 Elite chip with an active cooling fan, a huge 8550 mAh battery, and a starting price of 2799 yuan ($420), which is the sort of spec sheet that makes ”performance phone” sound a bit timid.
There is a clear strategy here: Xiaomi is leaning into raw endurance and sustained speed, while still keeping the entry price below what many flagship phones charge before the accessories even show up. That puts pressure on rivals that rely on passive cooling alone, especially in gaming-heavy markets where sustained performance matters more than a flashy peak benchmark.
Redmi K90 Ultra display and performance specs
The Redmi K90 Ultra uses a 6.83-inch flat AMOLED display with 1.5K resolution (2772 × 1280 pixels) and a 165 Hz refresh rate. Xiaomi says peak brightness reaches 3500 cd/m2, a figure aimed squarely at high-end rivals that increasingly use brightness as a bragging right.
- Chipset: Snapdragon 8 Elite, 3-nm
- Memory: 12 or 16 GB LPDDR5X
- Storage: up to 512 GB UFS 4.1
- Extra chip: Xiaomi D2 for AI upscaling and game frame interpolation
Active cooling fan and battery size
The oddest flex here is the cooling system, and in a good way. Xiaomi has built in an 18.1 mm fan rated at 32 dBA, paired with a 6000 mm2 vapor chamber, and even gave the cooling module separate IPX8 and IPX9 protection. That is more commitment than many brands show to the headphone jack.
Battery life should also be a major selling point. The 8550 mAh cell supports 100 W wired charging, 22.5 W reverse wired charging, and bypass charging, which should make the phone attractive to gamers and heavy users who care more about hours on screen than thinness in a promo shot.
Camera, software and Redmi K90 Ultra pricing
On the back, Xiaomi uses a 50-Mp Light Hunter 800 main camera with a 1/1.55-inch sensor, f/1.68 optics and optical image stabilization, alongside an 8-Mp ultrawide camera. The main camera records up to 8K video at 30 frames per second, while the 20-Mp front camera handles selfies and 1080p video.
The phone ships with Xiaomi HyperOS 3 and adds Bose-tuned stereo speakers, an ultrasonic 3D fingerprint scanner, an X-axis linear vibration motor, Wi-Fi 7 and Bluetooth 5.4. It is available in Shadow Black, Space Silver and Sky Blue, with pricing set at:
- 12 GB/256 GB: 2799 yuan ($420)
- 12 GB/512 GB: 3299 yuan ($495)
- 16 GB/256 GB: 2799 yuan ($420) at launch
- 16 GB/512 GB: 3499 yuan ($525)
That is aggressive pricing for a phone with a fan, a giant battery, and one of Qualcomm’s fastest chips, and it suggests Xiaomi wants spec hunters to do the math quickly before someone else does.