Xiaomi Redmi K90 Pro MaxvsSamsung Galaxy S21 Ultra

Xiaomi Redmi K90 Pro Max
#51
Winner
Processor:Qualcomm Snapdragon 8 Elite Gen 5
RAM:12 GBGB
Storage:256 GBGB

Quick Stats

Massive 7,560 mAh battery with 100W fast charging ensures multi-day endurance and rapid recharging.
Flagship-grade 6.9-inch QHD+ OLED display with 120Hz refresh rate and 3500 cd/m² brightness, TÜV Rheinland certified for eye comfort.
Triple rear cameras (108 MP, 50 MP ultra-wide, 50 MP telephoto) with AI enhancements deliver versatile photography, though digital zoom limits low-light performance.
Flagship Snapdragon 8 Elite Gen 5 with 12/16 GB RAM delivers top-tier performance, but active cooling struggles with prolonged gaming heat.
Samsung Galaxy S21 Ultra
#53
Processor:Samsung Exynos 2100
RAM:12 GBGB
Storage:128 GBGB

Quick Stats

The S21 Ultra's 5000mAh battery with 25W fast charging and adaptive display ensures all-day endurance.
The S21 Ultra's 120Hz adaptive display with HDR10+ and 1500 nits brightness delivers immersive, vibrant visuals.
The S21 Ultra’s 108MP main lens, 3x/10x optical zoom, and 8K video deliver pro-level photo and video capabilities.
The S21 Ultra's Exynos 2100 processor and 12GB RAM ensure smooth multitasking and lag-free performance for demanding apps and gaming.
Specifications Comparison
Specification
Xiaomi Xiaomi Redmi K90 Pro Max
Samsung Samsung Galaxy S21 Ultra
Model
Qualcomm Snapdragon 8 Elite Gen 5
Samsung Exynos 2100
CPU
2x4.61 GHz ARM + 6x3.63 GHz ARM
1x Cortex, X1 2,91 GHz + 3x Cortex, A78 2,81 GHz + 4x Cortex, A55 2,21 GHz.
Type
Octa-Core
Octa-Core
Nanometer
3 nm
5 nm
Frequency
4,6 GHz
2,9 GHz
64 Bits
Yes
Yes
GPU
Adreno 840 1.2 GHz
ARM Mali-G78 MP14
RAM
12 GB
12 GB
Type
RAM LPDDR5X
RAM LPDDR5
Capacity
256 GB
128 GB
Type
UFS Storage 4.1
UFS Storage 3.1
SD slot
No
No
Fingerprint security
Yes, in screen
Yes, in screen
Fingerprint sensor
Yes
Yes
Proximity sensor
N/A
Yes
Light sensor
Yes
Yes
Accelerometer sensor
Yes
Yes
Compass sensor
Yes
Yes
Gyroscope sensor
Yes
Yes
Barometer sensor
N/A
Yes
RGB sensor
Yes
N/A
Hall sensor
N/A
Yes
Geomagnetic sensor
N/A
Yes
Ultrasonic proximity virtual sensor
Yes
N/A
Audio
Dolby Atmos, Noise cancellation microphone, Stereo Speakers, 3 microphones
Dolby Atmos, Hi-Res Audio, Noise cancellation microphone, Stereo Speakers
Antutu Score
4350000
749000
Antutu Version
Antutu v10
Antutu v10
Antutu Standing
Overall performance better than 99% of devices
Overall performance better than 80% of devices
Cooling system
Yes
No
Gaming buttons
No
No
Extras
N/A
N/A

Note: Highlighted specifications show differences between the two devices.

Rankings
Connectivity
Xiaomi Redmi K90 Pro Max
#688
Samsung Galaxy S21 Ultra
#221
Winner
Design
Xiaomi Redmi K90 Pro Max
#49
Winner
Samsung Galaxy S21 Ultra
#100
Display
Xiaomi Redmi K90 Pro Max
#681
Samsung Galaxy S21 Ultra
#4
Winner
Performance
Xiaomi Redmi K90 Pro Max
#38
Winner
Samsung Galaxy S21 Ultra
#422
Battery
Xiaomi Redmi K90 Pro Max
#281
Winner
Samsung Galaxy S21 Ultra
#622
Camera
Xiaomi Redmi K90 Pro Max
#112
Samsung Galaxy S21 Ultra
#9
Winner

Note: Lower rank number indicates a better position in category.

Key Differences

No significant specification differences found between these devices.

Scores by Category
Pros and Cons

Xiaomi Redmi K90 Pro Max

Strengths

Flagship Snapdragon 8 Elite Gen 5 chipset ensures top-tier performance and multitasking.
Massive 7,560 mAh battery with 100W fast charging for all-day usage and rapid recharging.
6.9-inch QHD+ OLED display with 120 Hz refresh rate, 3500 cd/m² brightness, and HDR10+/Dolby Vision support.
Premium build with IP68 certification, aluminium alloy frame, and glass back for durability.
Innovative 2.1-channel audio system with subwoofer and Dolby Atmos for immersive sound.
Triple rear camera setup (108 MP primary, 50 MP ultra-wide, 50 MP telephoto) for versatile photography.

Weaknesses

Heavy 218 g weight may feel cumbersome for some users due to large battery and build materials.
Thicker bottom bezel compared to modern full-screen design trends.
Telephoto lens relies on digital zoom (no optical zoom mentioned), limiting low-light or far-range performance.
Potential overheating during extended gaming sessions despite active cooling system.
Screen-tearing reported in some games despite the D2 display chip and 120 Hz refresh rate.
Premium price point may deter budget-conscious buyers despite flagship specs.

Samsung Galaxy S21 Ultra

Strengths

Exceptional 120Hz adaptive display with HDR10+ and 1500 nits brightness for vibrant visuals.
Advanced quad-camera system with 108MP main lens, 3x/10x optical zoom, and 8K video recording.
Premium build with IP68 water resistance, Gorilla Glass Victus, and a sleek frameless design.
Powerful Exynos 2100 processor and Mali-G78 GPU for smooth multitasking and gaming.

Weaknesses

No expandable storage via SD card slot.
No bundled charger (25W fast charging requires purchase separately).
High price for a flagship device with non-removable battery.
Non-removable battery limits upgrade or replacement options.
Lacks periscope-style ultra-zoom compared to later flagships.
Read Full Reviews

Xiaomi Redmi K90 Pro Max

Xiaomi Redmi K90 Pro Max: A flagship with a massive display, powerful performance, and immersive audio. Capture stunning photos and enjoy long-lasting battery life in a rugged design.

Samsung Galaxy S21 Ultra

Experience the pinnacle of innovation with the Samsung Galaxy S21 Ultra. Its sleek, premium design merges a vibrant adaptive display with a powerful camera system, delivering breathtaking visuals and pro-level photography in a durable, edge-to-edge masterpiece.

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Read our detailed reviews to understand which device is better for your specific needs and budget.

Read Xiaomi Redmi K90 Pro Max ReviewRead Samsung Galaxy S21 Ultra Review

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