Home Phone comparison Samsung Galaxy S21 Ultra and Vivo iQOO 15 - Which is better?

Samsung Galaxy S21 Ultra vs Vivo iQOO 15

67 out 100
Samsung Galaxy S21 Ultra
VS
94 out 100
Vivo iQOO 15
Samsung Galaxy S21 Ultra
Vivo iQOO 15

Compared 2 smartphones : Samsung Galaxy S21 Ultra Manufactured in February, 2021, with display 6.8 with chipsetSamsung Exynos 2100, vs Vivo iQOO 15, Manufactured in October, 2025 with chipsetQualcomm Snapdragon 8 Elite Gen 5. Below are specs, tests, pros and cons for each device

  1. Differences
  2. Review
  3. Specs
  4. Benchmarks
  5. Battery Life
  6. Cameras
  7. Comments (0)

Key Differences

Device key advantages
Reasons to choose Samsung Galaxy S21 Ultra
  • Higher pixel density: 515ppi
  • Supports Dolby Atmos
  • Built-in eSIM
Reasons to choose Vivo iQOO 15
  • Larger display: 6.85in
  • Higher refresh rate: 144Hz
  • Lighter design: 220g vs 227g
  • Higher battery capacity: 7000mAh vs 5000mAh
  • Newer Bluetooth version: 6.0 vs 5.2
  • Supports DisplayPort
  • Infrared port
  • Includes charger

Versions

Available versions and configurations
Memory Options - 12/128 GB
- 12/256 GB
- 12/512 GB
- 16/256 GB
- 16/512 GB		 - 12/256 GB
- 12/512 GB
- 16/256 GB
- 16/512 GB
- 16/1024 GB

Review

Key Specs Samsung Galaxy S21 Ultra and Vivo iQOO 15
Display
Color accuracy, sharpness & brightness
Camera
Main & front camera tests
Performance
App & system performance
Games
3D gaming performance
Battery
Battery life, charging speed & type
Connectivity
Connectivity features
NanoReview Score
Overall score by NanoReview
Adjust each parameter’s importance to find the best match for you.
Customize your score
Function
Importance (Weight)
Display:
Camera:
Performance:
Gaming:
Battery:
Connectivity:
Higher weight means greater impact on NanoReview score.

Tests & specs

Specs & test comparison
Smartphones:
Galaxy S21 Ultra
vs
Vivo iQOO 15

Display

Display quality comparison
Type Dynamic AMOLED AMOLED
Size 6.8 in 6.85 in
Resolution 1440x3200 pixels 1440x3168 pixels
Aspect ratio 20:9 20:9
Pixel density 515 ppi 508 ppi
Refresh rate 120 Hz 144 Hz
Adaptive refresh rate Yes (10-120 Hz) Yes (1-120 Hz)
Max brightness 1500 nits 2600 nits
HDR support Yes HDR10+ Yes, HDR10+
Screen-to-body ratio 89.5 % 90.2 %
Features - DCI-P3
- Always-On Display		 - DCI-P3
- Always-On Display
- DC dimming
Display test
Peak brightness (auto)
Samsung Galaxy S21 Ultra
1019 nits
Vivo iQOO 15
n/a
Sources: NotebookCheck [Samsung Galaxy S21 Ultra]

Design & Build

Design and ergonomics comparison
Height 165.1 mm (6.5 in) 163.65 mm (6.44 in)
Width 75.6 mm (2.98 in) 76.8 mm (3.02 in)
Thickness 8.9 mm (0.35 in) 8.1 mm (0.32 in)
Weight 227 g (8.01 oz) 220 g (7.76 oz)
Water resistance IP68 IP69
Cooling system n/a Vapor chamber
Back panel Glass n/a
Frame Metal Metal
Colors - Black
- Silver
- Gray
- Blue		 - White
- Black
- Blue
Fingerprint sensor Yes In-Display Yes, In-Display
Screen-to-body ratio
Samsung Galaxy S21 Ultra
89.5 %
Vivo iQOO 15
90.2 %

Performance

Testing Samsung Galaxy S21 Ultra and Vivo iQOO 15 In benchmarks
Processor
Chipset Samsung Exynos 2100 Qualcomm Snapdragon 8 Elite Gen 5
Max Frequency 2900 MHz 4600 MHz
CPU Cores 8 (1 + 3 + 4) 8 (2 + 6)
Architecture - 4/2.2 (Cortex-A55)
- 3/2.81 (Cortex-A78)
- 1/2.91 (Cortex-X1)		 6/3.63 ()
Process Samsung TSMC
Transistor Size 5 nm 3 nm
Neural Processor Yes Hexagon
Graphics Mali-G78 MP14 Adreno 840
GPU Cores 896 1536
GPU Frequency 854 MHz 1200 MHz
FLOPS 1530.4 GFLOPS 3686.4 GFLOPS
GeekBench v6
Geekbench 6 (Single-Core)
Samsung Galaxy S21 Ultra
1449
Vivo iQOO 15
3641
Geekbench 6 (Multi-Core)
Samsung Galaxy S21 Ultra
3892
Vivo iQOO 15
10982
Geekbench 6 (Single-Core)14493641
Geekbench 6 (Multi-Core)389210982
Geekbench Compute (GPU)n/a27923
Sources: Geekbench v6 [Vivo iQOO 15]
AnTuTu 10
AnTuTu 10
Samsung Galaxy S21 Ultra
843008
Vivo iQOO 15
4009400
CPU2323581102463
GPU2563561429688
Memory163007516447
UX191217960802
NanoReview Score8430084009400
3DMark Wild Life
3DMark Wild Life
Samsung Galaxy S21 Ultra
5221
Vivo iQOO 15
n/a
Max Surface Temp.40.8 °Cn/a
Stability69 %n/a
Graphics Test31 fpsn/a
Graphics Score5221n/a
Sources: 3DMark [Samsung Galaxy S21 Ultra]

Memory

RAM
RAM Size - 12 GB
- 16 GB		 12 GB
Memory Type LPDDR5 LPDDR5X
Memory Frequency 2750 MHz 5300 MHz
Channels 2 4
Storage
Storage Capacity- 128 GB
- 256 GB
- 512 GB		256 GB
Storage TypeUFS 3.1UFS 4.1
Memory CardNoNo

Software

OS Android 11 (Upgradeable to Android 14) Android 16
OS Size 26.4 GB n/a
UI Skin One UI 6 OriginOS 6

Battery

Volume 5000 mAh 7000 mAh
Max Charging Power 25 W 100 W
Battery Type Li-ion Silicon Carbon (Si/C)
Removable No No
Wireless Charging Yes (15 W) Yes (40 W)
Reverse Charging Yes (Wireless) No
Fast Charging Yes (54% in 30 min) Yes
Full Charge Time 1:11 h n/a
Battery Life Test
Battery Life
Samsung Galaxy S21 Ultra
22:05
Vivo iQOO 15
n/a
Web Browsing07:58 hn/a
Video Playback13:59 hn/a
Games05:14 hn/a
Standby Mode111 hn/a

Main camera

Matrix 108 MP 50 MP
Photo resolution 12000x9000 pixels 8192x6144 pixels
Zoom Optical, 10x Optical, 3x
Flash Dual LED Dual LED
Stabilization Optical Optical
8K Recording Up to 24FPS Yes (Up to 30 fps)
4K Recording Yes (Up to 60 fps) Yes (Up to 60 fps)
1080p Recording Yes (Up to 60 fps) Yes (Up to 60 fps)
Slow Motion 960 fps (720p) 240 fps (1080p)
Wide-angle lens 120 ° n/a
Lenses count Standard: 108 MP
Telephoto: 10 MP
Telephoto: 10 MP
Ultra-wide: 12 MP		 Standard: 50 MP
Telephoto: 50 MP
Ultra-wide: 50 MP
Features - Bokeh effect
- Pro mode
- RAW support		 - Bokeh effect
- Pro mode
- RAW support
Main lens
Matrix108 MP50 MP
Aperturef/1.8f/1.9
Focal length26 mm23 mm
SensorSamsung S5KHM3n/a
Sensor size1/1.331/1.56
Pixel size0.8 μm1 μm
AutofocusLaser autofocusPhase autofocus
StabilizationOpticalOptical
Telephoto
Matrix10 MP50 MP
Aperturef/4.9f/2.7
Focal length240 mmn/a
SensorSamsung S5K3J1n/a
Sensor size1/2.651/1.95
Pixel size1.22 μm0.8 μm
StabilizationOpticalOptical
Ultra-wide lens
Matrix12 MP50 MP
Aperturef/2.2f/2.1
Focal length13 mm15 mm
SensorSony IMX563n/a
Sensor size1/2.551/2.76
Pixel size1.4 μm0.64 μm
StabilizationDigitalDigital
Main camera DxOMark results
Photo quality
Samsung Galaxy S21 Ultra
121
Vivo iQOO 15
n/a
Video quality
Samsung Galaxy S21 Ultra
100
Vivo iQOO 15
n/a
Overall camera score
Samsung Galaxy S21 Ultra
115
Vivo iQOO 15
n/a
Bokeh70n/a
Preview67n/a
Zoom106n/a
Sources: DxOMark [Samsung Galaxy S21 Ultra]

Front camera

Matrix 40 MP 32 MP
Photo resolution 7864x5200 pixels n/a
Aperture f/2.2 f/2.2
Focal length 26 mm 21 mm
Sensor Samsung S5KGH1 CMOS
Sensor size 1/2.65 n/a
Pixel size 0.7 μm n/a
Autofocus Phase autofocus No
Stabilization Digital Digital
Video resolution 2160p (4K) at 60 fps 2160p (4K) at 60 fps
TOF 3D sensor No No
Selfie camera DxOMark results
Photo quality
Samsung Galaxy S21 Ultra
133
Vivo iQOO 15
n/a
Video quality
Samsung Galaxy S21 Ultra
140
Vivo iQOO 15
n/a

Connectivity

Wi-Fi version Wi-Fi 6E (802.11 a/b/g/n/ac/ax) Wi-Fi 7 (802.11 a/b/g/n/ac/ax/be)
Wi-Fi features - Dual Band
- Wi-Fi MiMO
- Wi-Fi Direct
- Wi-Fi Hotspot
- Wi-Fi Display		 - Dual Band
- Wi-Fi MiMO
- Wi-Fi Direct
- Wi-Fi Hotspot
- Wi-Fi Display
Bluetooth version 5.2 6.0
Bluetooth features LE, A2DP LE
USB type USB Type-C USB Type-C
USB version 3.2 3.2
USB features - Charging
- USB Storage Mode
- USB-Host mode
- OTG		 - Charging
- USB Storage Mode
- OTG
DisplayPort n/a Yes
GPS - GPS
- GLONASS
- Beidou
- Galileo		 - GPS
- GLONASS
- Beidou
- Galileo
- QZSS
NFC* Yes Yes
Infrared Port No Yes
Connectivity
SIM Count*22
SIM TypeNanoNano
SIM ModeDual SIM StandbyDual SIM Standby
eSIM Support *YesNo
Hybrid SlotNoNo
2G BandsGSM 850, 900, 1800, 1900 MHzGSM 850/900/1800/1900MHz
3G BandsWCDMA Band 1, 2, 4, 5, 8WCDMA B1/B2/B4/B5/B6/B8/B19
LTE Bands*LTE (B1/B2/B3/B4/B5/B7/B8/B12/B13/B17/B18/B19/B20/B25/B26/B28/B32/B38/B39/B40/B41/B66)LTE (B1/B2/B3/B4/B5/B7/B8/B18/B19/B20/B26/B28/B38/B40/B41/B42/B66)
LTE category24n/a
5G SupportYesYes

Sound

Speakers Stereo n/a
3.5 mm Jack No No
FM Radio No No
Dolby Atmos Yes n/a
Speaker Test
Max Volume
Samsung Galaxy S21 Ultra
88 dB
Vivo iQOO 15
n/a

Other

Class Flagship Flagship
Announced January, 2021 yr October, 2025 yr
Release Date February, 2021 yr October, 2025 yr
Launch Price ($) 1200 n/a
MSRP ($) n/a 590
Sensors - Hall Sensor
- Barometer
- Proximity Sensor
- Gyroscope
- Accelerometer
- Ambient Light Sensor
- Compass
- Fingerprint sensor		 - Proximity Sensor
- Gyroscope
- Accelerometer
- Ambient Light Sensor
- Compass
- Fingerprint sensor
Charger Included n/a Yes, 100 W
* Attention! Config, frequencies, NFC, and other specs may vary by region.

Results

After analyzing the data, we consider Vivo iQOO 15 the clear winner in this comparison.

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