Xiaomi 15 Ultra vs Samsung Galaxy S21 Ultra
90
out of 100
VS
62
out of 100
Here we compared two flagship smartphones: the 6.73-inch Xiaomi 15 Ultra (with Qualcomm Snapdragon 8 Elite) that was released on February 27, 2025, against the Samsung Galaxy S21 Ultra, which is powered by Exynos 2100 and came out 4 years and 2 months before. On this page, you will find tests, full specs, strengths, and weaknesses of each of the devices.
Select the amount of RAM to evaluate performance and value for money more precisely
Key differences
Reasons to consider the Xiaomi 15 Ultra
- 2.8x better performance in AnTuTu Benchmark (3030K versus 1074K)
- Better camera quality (According to DxOMark rating)
- Shows 36% longer battery life (30:03 vs 22:05 hours)
- Delivers 57% higher peak brightness (1588 against 1013 nits)
- Newer Bluetooth version (v6.0)
- Has 50% more RAM: 12GB versus 8GB
- Supports higher wattage charging (90W versus 25W)
- Compatible with Wi-Fi 7 wireless networks
- The phone is 4 years and 2 months newer
- More recent OS version: Android 16 versus 15
- Slow-motion recording at 1920FPS
- Has a built-in infrared port
Reasons to consider the Samsung Galaxy S21 Ultra
- The rear camera has a 10x optical zoom
Review
Display
Screen quality, color accuracy, brightness
Camera
Photo and video recording quality
Performance
CPU and memory performance (apps, system)
Gaming
Capabilities for playing modern games
Battery
Battery life, charging type and speed
Connectivity
Networks, ports, data transmission
Select your primary usage scenario to get a more accurate DeviceFacts Score
Value for money (Beta)
Tests and specifications
Comparison table of technical specifications and testsDisplay
| Type | AMOLED | Dynamic AMOLED |
| Size | 6.73 inches | 6.8 inches |
| Resolution | 1440 x 3200 pixels | 1440 x 3200 pixels |
| Aspect ratio | 20:9 | 20:9 |
| PPI | 522 ppi | 515 ppi |
| Refresh rate | 120 Hz | 120 Hz |
| Adaptive refresh rate | Yes (1-120 Hz) | Yes (10-120 Hz) |
| Max rated brightness | 1600 nits | 1500 nits |
| Max rated brightness in HDR | 3200 nits | - |
| HDR support | Yes, Dolby Vision | Yes, HDR10+ |
| Touch sampling rate | 300 Hz | - |
| Screen protection | Xiaomi Shield Glass 2.0 | Gorilla Glass Victus |
| Screen-to-body ratio | 90% | 89.5% |
| Display features | - DCI-P3 - Always-On Display - DC Dimming |
- DCI-P3 - Always-On Display |
| RGB color space | 99.7% | - |
| PWM | 120 Hz | - |
| Response time | 1 ms | - |
| Contrast | ∞ Infinity | - |
Peak brightness test (auto)
Design and build
| Height | 161.3 mm (6.35 inches) | 165.1 mm (6.5 inches) |
| Width | 75.3 mm (2.96 inches) | 75.6 mm (2.98 inches) |
| Thickness | 9.35 mm (0.37 inches) | 8.9 mm (0.35 inches) |
| Weight | 226 g (7.97 oz) | 227 g (8.01 oz) |
| Waterproof | IP68 | IP68 |
| Advanced cooling | Vapor chamber | - |
| Rear material | Glass | Glass |
| Frame material | Metal | Metal |
| Colors | White, Black, Silver, Green | Black, Silver, Gray, Blue |
| Fingerprint scanner | Yes, in-display | Yes, in-display |
| Repairability | Average (2.61/5) | - |
| Drop resistance | Good (C) · 90 drops | - |
Screen-to-body ratio
Performance
| Chipset | Qualcomm Snapdragon 8 Elite | Samsung Exynos 2100 |
| Max clock | 4320 MHz | 2900 MHz |
| CPU cores | 8 (2 + 6) | 8 (1 + 3 + 4) |
| Architecture | - 6 cores at 3.53 GHz: Oryon (Phoenix M) - 2 cores at 4.32 GHz: Oryon (Phoenix L) |
- 4 cores at 2.2 GHz: Cortex-A55 - 3 cores at 2.81 GHz: Cortex-A78 - 1 core at 2.91 GHz: Cortex-X1 |
| L3 cache | 8 MB | - |
| Manufacturing | TSMC | Samsung |
| Lithography process | 3 nanometers | 5 nanometers |
| Neural processor (NPU) | Hexagon | Yes |
| Graphics | Adreno 830 | Mali-G78 MP14 |
| GPU shading units | 1536 | 448 |
| GPU clock | 1100 MHz | 854 MHz |
| FLOPS | ~3379.2 GFLOPS | ~765.2 GFLOPS |
Benchmarks
Geekbench 6 (Single-Core)
Geekbench 6 (Multi-Core)
Compute Score (GPU)
| Compute Score (GPU) | 24339 | 6870 |
| Single-core score | 3106 | 1486 |
| Multi-core score | 9710 | 3800 |
AnTuTu Benchmark 11
| CPU | 912791 | 420330 |
| GPU | 1097348 | 186151 |
| Memory | 440343 | 193925 |
| UX | 579894 | 273776 |
| Total score | 3030376 | 1074182 |
| Samples | [12 tests] | [11 tests] |
3DMark Steel Nomad Light
| Stability | 76% | - |
| Graphics test | 16 FPS | - |
| Graphics score | 2151 | - |
3DMark Solar Bay
| Graphics test | 37 FPS | - |
| Section 1 | 42 FPS | - |
| Section 2 | 38 FPS | - |
| Section 3 | 32 FPS | - |
| Graphics score | 9815 | - |
3DMark Wild Life Extreme
| Stability | 85% | - |
| Graphics test | 33 FPS | - |
| Graphics score | 5626 | - |
PCMark 3.0
| Web score | 19993 | - |
| Video editing | 8213 | - |
| Photo editing | 36597 | - |
| Data manipulation | 17882 | - |
| Writing score | 22481 | - |
AnTuTu 11 Ranking List (#111th place)
Recent User Tests
Xiaomi 15 Ultra
| Date | Benchmark | Result |
|---|---|---|
| 📘 2026-09-27 (dmxsan) | AnTuTu 12 | 3059557 |
| 📘 2026-07-07 (average f-4 enjoyer) | AnTuTu 11 | 2993761 |
| 📘 2026-06-28 (Mansur) | Battery life | SOT 12:59 / 16:48 |
| 📘 2026-02-22 (XX5mipiXX) | AnTuTu 11 | 3108699 |
| 📘 2026-01-27 -> MiEmirr | Geekbench 6 CPU | 3127 / 9465 |
Samsung Galaxy S21 Ultra
| Date | Benchmark | Result |
|---|---|---|
| 📘 2026-10-06 (Nurik) | AnTuTu 12 | 900228 |
| 📘 2026-09-30 -> fh_hxx19 | AnTuTu 12 | 1191592 |
| 📘 2026-09-30 -> fh_hxx19 | AnTuTu 12 | 1191592 |
| 📘 2026-07-22 (Squizzyyy) | AnTuTu 11 | 857016 |
| 📘 2026-06-02 (My name) | AnTuTu 11 | 1271841 |
Memory
| RAM size | 12 GB | 8 GB |
| Memory type | LPDDR5X | LPDDR5 |
| Memory clock | 5300 MHz | 2750 MHz |
| Channels | 4 | 2 |
| Storage size | 256 GB | 128 GB |
| Storage type | UFS 4.1 | UFS 3.1 |
| Memory card | No | No |
Software
| Operating system | Android 15 (Can be upgraded to Android 16) | Android 11 (Can be upgraded to Android 15) |
| ROM | HyperOS 3.0 | One UI 7.0 |
| OS size | 23.9 GB | 26.4 GB |
| OS updates | 4 years | 2 years |
| Security updates | 7 years | 4 years |
Battery
| Capacity | 5410 mAh | 5000 mAh |
| Max charge power | 90 W | 25 W |
| Battery type | Silicon-Carbon (Si/C) | Li-Ion |
| Replaceable | No | No |
| Wireless charging | Yes (80 W) | Yes (15 W) |
| Reverse charging | Yes, (wireless) | Yes, (wireless) |
| Bypass charging | No | - |
| Fast charging | Yes (72% in 30 min) | Yes (54% in 30 min) |
| Full charging time | 0:51 hr | 1:11 hr |
| Battery cycles | 1000 cycles | - |
| Web browsing | 12:19 hr | 07:58 hr |
| Watching video | 18:43 hr | 13:59 hr |
| Gaming | 06:45 hr | 05:14 hr |
| Standby | 141 hr | 111 hr |
General battery life
Smartphones With Long Battery Life (#45th place)
Main camera
| Matrix | 50 megapixels | 108 megapixels |
| Image resolution | 8192 x 6144 | 12000 x 9000 |
| Zoom | Optical, 4.3x | Optical, 10x |
| Flash | Dual LED | Dual LED |
| Stabilization | Optical | Optical |
| 8K video recording | Up to 30FPS | Up to 24FPS |
| 4K video recording | Up to 120FPS | Up to 60FPS |
| 1080p video recording | Up to 60FPS | Up to 60FPS |
| Slow motion | 1920 FPS (1080p) | 960 FPS (720p) |
| Angle of widest lens | 115° | 120° |
| Lenses | 1) Standard: 50 MP 2) Telephoto: 200 MP 3) Telephoto: 50 MP 4) Ultrawide: 50 MP 5) Depth |
1) Standard: 108 MP 2) Telephoto: 10 MP 3) Telephoto: 10 MP 4) Ultrawide: 12 MP |
| Camera features | - Bokeh mode - Pro mode - RAW support |
- Bokeh mode - Pro mode - RAW support |
| Image resolution | 50 MP | 108 MP |
| Aperture | f/1.63 | f/1.8 |
| Focal length | 23 mm | 26 mm |
| Sensor | Sony LYT-900 | Samsung S5KHM3 |
| Sensor size | 1/1.0" (≈ 1 inch) | 1/1.33" (≈ 0.75 inch) |
| Pixel size | 1.6 micron | 0.8 micron |
| Autofocus | Laser autofocus | Laser autofocus |
| Stabilization | Optical | Optical |
| Image resolution | 200 MP | 10 MP |
| Aperture | f/2.6 | f/4.9 |
| Focal length | 100 mm | 240 mm |
| Sensor | Samsung ISOCELL S5KHP9 | Samsung S5K3J1 |
| Sensor size | 1/1.4" (≈ 0.71 inch) | 1/2.65" (≈ 0.38 inch) |
| Pixel size | 0.56 micron | 1.22 micron |
| Stabilization | Optical | Optical |
| Image resolution | 50 MP | 12 MP |
| Aperture | f/2.2 | f/2.2 |
| Focal length | 14 mm | 13 mm |
| Sensor | Samsung S5KJN5 | Sony IMX563 |
| Sensor size | 1/2.76" (≈ 0.36 inch) | 1/2.55" (≈ 0.39 inch) |
| Pixel size | 0.64 micron | 1.4 micron |
| Stabilization | Digital | Digital |
DxOMark main camera tests
Photo quality
Video quality
Generic main camera score
| Bokeh | 170 | 70 |
| Preview | 89 | 67 |
| Zoom | 166 | 106 |
| Samples | Photo samples of Xiaomi 15 Ultra from DxOMark | Photo samples of Samsung Galaxy S21 Ultra from DxOMark |
Selfie camera
| Megapixels | 32 megapixels | 40 megapixels |
| Image resolution | 6528 x 4896 | 7864 x 5200 |
| Aperture | f/2.0 | f/2.2 |
| Focal length | 22 mm | 26 mm |
| Sensor | Omnivision OV32B | Samsung S5KGH1 |
| Sensor size | 1/3.14" (≈ 0.32 inch) | 1/2.65" (≈ 0.38 inch) |
| Pixel size | 0.7 micron | 0.7 micron |
| Autofocus | No | Phase autofocus |
| Stabilization | Digital | Digital |
| Video resolution | 2160p (4K) at 60 FPS | 2160p (4K) at 60 FPS |
| Depth sensor (TOF 3D) | No | No |
DxOMark front camera
| Photo | - | 133 |
| Video | - | 140 |
Connectivity
| Wi-Fi standard | Wi-Fi 7 (802.11 a/b/g/n/ac/ax/be) | Wi-Fi 6E (802.11 a/b/g/n/ac/ax) |
| 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 | 6.0 | 5.2 |
| Bluetooth features | LE | LE, A2DP |
| USB type | USB Type-C | USB Type-C |
| USB version | 3.2 | 3.2 |
| USB features | - Charging - USB-Storage mode - OTG |
- Charging - USB-Storage mode - USB-Host mode - OTG |
| DisplayPort | Yes | - |
| GPS | GPS, GLONASS, Beidou, Galileo, QZSS, NAVIC | GPS, GLONASS, Beidou, Galileo |
| NFC* | Yes | Yes |
| Infrared port | Yes | No |
| Number of SIM* | 2 | 2 |
| Type of SIM card | Nano | Nano |
| Multi SIM mode | Standby | Standby |
| eSIM support* | Yes | Yes |
| Hybrid slot | No | No |
| LTE Cat* | - | 24 |
| 5G support | Yes | Yes |
Sound
| Speakers | Stereo | Stereo |
| Headphone audio jack | No | No |
| FM radio | No | No |
| Dolby Atmos | Yes | Yes |
Speakers test
Max loudness
Other
| Category | Flagship | Flagship |
| Announced | February 2025 | January 2021 |
| Release date | February 2025 | February 2021 |
| Launch price (MSRP) | $1099 | $1200 |
| Successor | - Xiaomi 17 Ultra | - Samsung Galaxy S22 Ultra |
| SAR (head) | - | 0.71 W/kg |
| SAR (body) | - | 1.58 W/kg |
| Sensors | - Barometer - Proximity sensor - Gyroscope - Accelerometer - Ambient light sensor - Compass - Fingerprint |
- Hall-effect sensor - Barometer - Proximity sensor - Gyroscope - Accelerometer - Ambient light sensor - Compass - Fingerprint |
| Bundled charger | Yes, 90 W | - |
Further details
Notes on 15 Ultra:
- The Chinese version of the Xiaomi 15 Ultra has a 6000 mAh battery, while the international model comes with 5410 mAh, leading to a noticeable difference in battery life.
*Disclaimer! NFC, GSM network support, and some other specs can be different depending on the country.
Conclusion
After analyzing all the data, we think that the Xiaomi 15 Ultra is definitely a better buy.
Cast your vote
Total votes: 4