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Galaxy S21 Ultra 5G vs Redmi K40 Gaming

Samsung Galaxy S21 Ultra 5G vs Xiaomi Redmi K40 Gaming

What Galaxy S21 Ultra 5G does better (20) and where Redmi K40 Gaming wins (6) — every spec side by side.

Samsung · 2021Galaxy S21 Ultra 5G

9.0Score

20 advantages≈ $260

Higher score

Xiaomi · 2021Redmi K40 Gaming

8.0Score

6 advantages≈ $280

9.1Display7.2

9.8Camera7.2

6.2Battery8.0

9.4Features6.9

Dimensions

Size comparison

Galaxy S21 Ultra 5GRedmi K40 Gaming

	Galaxy S21 Ultra 5G	Redmi K40 Gaming	Difference
Height	165.1 mm	161.9 mm	+3.2 mm
Width	75.6 mm	76.9 mm	−1.3 mm
Thickness	8.9 mm	8.3 mm	+0.6 mm
Weight	227 g	205 g	+22 g

Drawn to the same scale from the official dimensions (front and side).

Why is Galaxy S21 Ultra 5G better than Redmi K40 Gaming?

Water resistance (IPx)IPx8 vs IPx32.7×
Peak brightness1,500 nits vs 500 nits3×
Main camera108 MP vs 64 MP+69%
Storage (max)512 GB vs 256 GB2×
Optical stabilisationYes · Redmi K40 Gaming: No
Telephoto cameraYes · Redmi K40 Gaming: No
Wireless chargingYes · Redmi K40 Gaming: No
RAM16 GB vs 12 GB+33%
Selfie camera40 MP vs 16 MP2.5×
Pixel density515 ppi vs 395 ppi+30%
Rear cameras4 vs 22×
Max video8K vs 4K

Why is Redmi K40 Gaming better than Galaxy S21 Ultra 5G?

Wired charging25 W vs 67 W2.7×
Weight227 g vs 205 g+11%
CPU frequency2.9 GHz vs 3 GHz+3%
Charged in 30 min54% vs 71%+31%
Thickness8.9 mm vs 8.3 mm+7%
Main camera aperturef/1.8 vs f/1.7+6%

Specifications

Side by side

Only differences	Samsung Galaxy S21 Ultra 5G≈ $2609.0	Xiaomi Redmi K40 Gaming≈ $2808.0
Design
Weight	227 g	205 g
Thickness	8.9 mm	8.3 mm
Height	165.1 mm	161.9 mm
Width	75.6 mm	76.9 mm
Frame	Aluminium	—
Back	Glass	Glass
Ingress protection	IP68	IP53
Water resistance (IPx)	IPx8	IPx3
Glass protection	Corning Gorilla Glass Victus	Corning Gorilla Glass 5
Colours	Phantom Black, Phantom Silver, Phantom Titanium, Phantom Navy, Phantom Brown, Navy	Black, Gray, Silver, Bruce Lee Yellow
Stylus	Yes	—
Display
Screen size	6.8″	6.7″
Panel	Dynamic AMOLED 2X	OLED
OLED panel	Yes	Yes
Resolution (width)	1,440 px	1,080 px
Resolution (height)	3,200 px	2,400 px
Pixel density	515 ppi	395 ppi
Refresh rate	120 Hz	120 Hz
Peak brightness	1,500 nits	500 nits
Measured brightness	1,023 nits	—
Screen-to-body ratio	89.8%	86.3%
HDR	Yes	Yes
Performance
Chipset	Exynos 2100 - International	Mediatek Dimensity 1200
Chip maker	Qualcomm	MediaTek
Process	5 nm	6 nm
CPU cores	8	8
CPU frequency	2.9 GHz	3 GHz
GPU	Mali-G78 MP14 - International Adreno 660 - USA/China	Mali-G77 MC9
AnTuTu score	657,150	—
Geekbench 6 (multi-core)	3,518	—
Memory
RAM	16 GB	12 GB
Storage (max)	512 GB	256 GB
Storage (base)	128 GB	128 GB
Storage type	UFS 3.1	UFS 3.1
Memory card slot	No	No
Camera
Main camera	108 MP	64 MP
Main camera aperture	f/1.8	f/1.7
Main sensor size	1/1.33"	1/2.0"
Rear cameras	4	2
Optical stabilisation	Yes	No
Ultra-wide camera	Yes	Yes
Telephoto camera	Yes	No
Optical zoom	10×	—
Max video	8K	4K
4K video frame rate	60 fps	30 fps
Selfie camera	40 MP	16 MP
4K selfie video	Yes	No
Battery
Battery capacity	5,000 mAh	5,065 mAh
Battery type	Li-Ion	Li-Po
Wired charging	25 W	67 W
Charged in 30 min	54%	71%
Wireless charging	Yes	No
Wireless charging power	15 W	—
Reverse wireless charging	Yes	—
Connectivity
5G	Yes	Yes
eSIM	Yes	No
Dual SIM	Yes	Yes
Wi-Fi standard	Wi-Fi 6E	Wi-Fi 6
Bluetooth	5.2	5.2
NFC	Yes	Yes
USB	USB Type-C 3.2	USB Type-C 2.0
USB version	3.2	2
Ultra Wideband	Yes	—
Dual-band GPS	—	Yes
Satellite navigation	GLONASS, GALILEO, BDS	GLONASS, GALILEO, BDS, QZSS, NavIC
Features
Stereo speakers	Yes	Yes
3.5 mm headphone jack	No	No
Loudspeaker loudness	-25.5 LUFS	—
Fingerprint sensor	Under display, ultrasonic	Side
Barometer	Yes	Yes
Sensors	Fingerprint (under display, ultrasonic), accelerometer, gyro, proximity, compass, barometer	Fingerprint (side-mounted), accelerometer, gyro, compass, barometer
SAR (head)	0.71 W/kg	—
Software
OS at launch	Android 11	Android 11
Platform	Android	Android
Interface	One UI 7	MIUI 12.5
Major OS updates promised	4	—