Xiaomi Poco X3 GT (256GB) vs Samsung Galaxy S21 Ultra (SM-G998U1 256GB)
Side by side comparison between Xiaomi Poco X3 GT vs Samsung Galaxy S21 Ultra phones, differences, pros, cons and full specifications. What's the better?
,
6.6"
IPS
IPS
1080x2400
64
MP
MP
16mp
8GB
RAM
RAM
Octa-core
5000
mAh
mAh
(Non removable)
vs
6.8"
AMOLED
AMOLED
1440x3200
108
MP
MP
40mp
12GB
RAM
RAM
Octa-core
5000
mAh
mAh
(Non removable)
What's the better phone? Samsung Galaxy S21 Ultra (SM-G998U1 256GB)
The phonemore's choice is much more technical than personal. Therefore, you shouldn't only consider this. Our goal is to help you, but what's important to us may not be important to you. You decide which one is the best! Comment!
2 Advantages 
26 Advantages | 28 Common items in both devices |
| 256GB (230GB available) / 256GB (220GB available) |
| UFS 3.1 |
| 8.9 millimeters (0.35 inches) |
| 120Hz |
| 16 million |
| LED flash |
| PDAF: phase detection autofocus / PDAF: phase detection autofocus on both cameras |
| +21 specs and more in the table below |
Check the comparison table below for more items that are not evaluated in comparison score above.
Highlight differences Clear highlight📱 Model features | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| Model | Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) |
| Other model names | POCO X3 GT (21061110AG) | Galaxy S21 Ultra 5G (SM-G998U1) Unlocked |
| Country or region available |  (Global, International) |  USA |
| Brand | Xiaomi | Samsung |
| Release date | 8/19/2021, Announced: 7/28/2021 | 1/29/2021, Announced: 1/14/2021 |
| Depth | 8.9 millimeters (0.35 inches) | 8.9 millimeters (0.35 inches) |
| Size (width x height) | 75.9 x 163.3 millimeters (2.99 x 6.43 in) | 75.6 x 165.1 millimeters (2.98 x 6.5 in) |
| Weight | 193 grams (6.76 ounces) | 227 grams (7.95 ounces) |
| Build, materials | Plastic body, glass front | Aluminum frame, glass front/back |
| Protection against water and others | IP53 certified: protection against dust and splashing | IP68 certified: water-resistant up to 1.5 meters for 30min and dust-resistant |
📲 Display | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| Display type | TFT IPS LCD | Dynamic AMOLED |
| Screen size | 6.6" inches | 6.8" inches |
| Screen-to-body ratio | ~84.9% (screen-to-body ratio) | ~89.4% (screen-to-body ratio) |
| Display resolution | 1080x2400 pixels (20:9) | 1440x3200 pixels (20:9) |
| Touchscreen | Capacitive Multitouch | Capacitive Multitouch 10-points |
| Pixel density (dot pitch) | 399 PPI | 516 PPI |
| Colors | 16 million | 16 million |
| Scratch-resistant glass | Gorilla Glass Victus | Gorilla Glass Victus |
| Refresh rate | 120Hz | 120Hz |
| Display features | 450nits[typ] HDR10 | 1500nits[peak] HDR10+ Always-On Display |
🤖 Operating System | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| System version | Android 11 | Android 11 |
| Firmware update | Android 12 | Android 14 |
| User Interface | MIUI 12.5 / 13 | One UI 3.1 / 4.1 / 5.1 / 6.0 |
⚙️ Processor | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| Chipset | 64bit: MediaTek Dimensity 1100 (MT6891Z) (6nm) | 64bit: Qualcomm Snapdragon 888 (SM8350) (5nm) |
| CPU | Octa-core, 2 processors: 4x 2.6GHz ARM Cortex-A78 (Quad-core) 4x 2GHz ARM Cortex-A55 (Quad-core) | Octa-core, 3 processors: 1x 2.84GHz Kryo 680 (Single-core) 3x 2.42GHz Kryo 680 (Triple-core) 4x 1.8GHz Kryo 680 (Quad-core) |
| GPU graphical controller | ARM Mali-G77 MC9 (836MHz) | Qualcomm Adreno 660 (840MHz) |
| Performance (benchmark) | AnTuTu: 506800 (v8), 578505 (v9) Geekbench: 2310 (v5.1) GFXBench: 38fps (ES 3.1 onscreen) | AnTuTu: 681099 (v8), 809165 (v9) Geekbench: 3539 (v5.2) GFXBench: 54fps (ES 3.1 onscreen) |
💽 Memory and storage | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| RAM memory | 8GB LPDDR4X | 12GB LPDDR5 |
| Internal storage | 256GB (230GB available) UFS 3.1 | 256GB (220GB available) UFS 3.1 |
| External storage | Not supported | Not supported |
📶 Mobile networks | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| Dual-SIM | Dual-SIM Standby - Call active on one sim card | Dual-SIM Standby - Call active on one sim card |
| SIM card | 2 slots (Dual-SIM) nano-SIM (4FF) | 1 slot (Single-SIM) nano-SIM (4FF) + e-SIM |
| Maximum Download / Upload | 2000/1024 Mbps | 5000/1920 Mbps |
| Network technology | 2G, 3G, 4G, 5G | 2G, 3G, 4G, 5G |
| Frequency, bands | Expand band details Collapse details | |
| GSM MHz band | Quad-Band 850/900/1800/1900 | Quad-Band 850/900/1800/1900 |
| Primary 2G network | GSM 850/900/1800/1900 | CDMA 800/1900, GSM 850/900/1800/1900 |
| Primary 3G network | UMTS 850/900/1700/1900/2100 | CDMA2000 1xEV-DO UMTS 850/900/1700/1900/2100 |
| Primary 4G network | LTE Cat6 (1, 2, 3, 4, 5, 7, 8, 18, 19, 26, 28) TD-LTE (38, 40, 41, 42) VoLTE | LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 18, 19, 20, 25, 26, 28, 30, 66, 71) TD-LTE (38, 39, 40, 41, 46, 48) VoLTE |
| Primary 5G network | SA/NSA (1, 3, 28, 41, 77, 78) | SA/NSA/Sub6 (2, 5, 25, 41, 66, 71) mmWave (260, 261) |
| Primary data network | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA | GPRS, EDGE, CDMA2000 EV-DO Rev 0, CDMA2000 EV-DO Rev A, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 |
| Secondary 2G network | GSM 850/900/1800/1900 | CDMA 800/1900, GSM 850/900/1800/1900 |
| Secondary 3G network | UMTS 850/900/1700/1900/2100 | CDMA2000 1xEV-DO UMTS 850/900/1700/1900/2100 |
| Secondary 4G network | LTE Cat6 (1, 2, 3, 4, 5, 7, 8, 18, 19, 26, 28) TD-LTE (38, 40, 41, 42) VoLTE | LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 13, 14, 18, 19, 20, 25, 26, 28, 30, 66, 71) TD-LTE (38, 39, 40, 41, 46, 48) VoLTE |
| Secondary data network | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A | GPRS, EDGE, CDMA2000 EV-DO Rev 0, CDMA2000 EV-DO Rev A, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA, Sub6 |
📷 Camera | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| Back camera (main camera) | (triple camera) 64 megapixels 8MP ultrawide f/2.2120°1/4"1.12µm 2MP macro f/2.4 | (quad camera) 108 megapixels 10MP periscope telephoto f/4.9240mm1/3.24"1.22µmPDAFOIS10x-optical-zoom 10MP telephoto f/2.470mm1/3.24"1.22µmPDAFOIS3x-optical-zoom 12MP ultrawide f/2.213mm1/2.55"1.4µmPDAFSuper-Steady-video |
| Main camera resolution | 10120x6328 pixels | 12000x9000 pixels |
| Video recording (primary) | 4K UHD (3840x2160) 30 fps | 8K UHD (7680x4320) 24 fps |
| Flash | LED flash | LED flash |
| Focal aperture | f/1.8 (aperture) | f/1.8 (aperture) |
| Focal length | 26mm lens | 26mm lens |
| Sensor size | 1/1.97" inches | 1/1.33" inches |
| Pixel size | 0.7µm pixel | 1.8µm pixel |
| Autofocus | PDAF: phase detection autofocus | PDAF: phase detection autofocus on both cameras |
| Touch focus | Supported | Supported |
| Image stabilization | EIS: Digital stabilization | OIS: Optical stabilization |
| Zoom | Only digital zoom | Digital and optical zoom |
| Face/smile detection | Face detection, Smile detection | Face detection, Smile detection |
| BSI sensor | Supported | Supported |
| HDR | HDR photo on both cameras | HDR photo/video on both cameras |
| Camera extras | feature not registered | 4K@60fps 1080p@240fps 720p@960fps |
📸 Front camera | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| Front camera (secondary) | 16 megapixels | 40 megapixels |
| Front camera resolution | 4608x3456 pixels | 7296x5472 pixels |
| Video recording (secondary) | Full HD (1920x1080) | 4K UHD (3840x2160) |
| Front flash | Not supported | Not supported |
| Focal aperture | f/2.5 (aperture) | f/2.2 (aperture) |
| Focal length | feature not registered | 26mm lens |
| Sensor size | 1/3.06" inches | 1/2.8" inches |
| Pixel size | 1µm pixel | 0.7µm pixel |
🔉 Sound and multimedia | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| Loudspeaker | Stereo sound with dual speakers 24-bit/192kHz Tuned by JBL | Stereo sound 32-bit/384kHz Dolby Atmos Tuned by AKG |
| Active noise cancellation | 2 microphones or more | 2 microphones or more |
| Radio | Not supported | FM |
| TV | Not supported | Not supported |
| Video formats | MP4, H.265, H.264, H.263, XviD, MKV | MP4, H.265, H.264, H.263, XviD, MKV |
| Audio formats | MP3, WAV, WMA, eAAC+, FLAC | MP3, WAV, WMA, eAAC+, FLAC |
🔌 Connectivity | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| USB | USB 2.0 Type-C, USB OTG On-The-Go | USB 3.2 Type-C, USB OTG On-The-Go |
| Audio output | Type-C jack with 3.5mm jack adapter | Type-C reversible connector |
| TV output | USB Type-C (reversible) | USB Type-C (reversible) |
| Bluetooth | 5.2 + A2DP/LE | 5.2 + A2DP/LE |
| WiFi | 802.11 a/b/g/n/ac/ax [wifi6] (2.4GHz, 5GHz) + MIMO WiFi Direct, hotspot | 802.11 a/b/g/n/ac/ax [wifi6] (2.4GHz, 5GHz) + MIMO WiFi Direct, hotspot |
| DLNA | Not supported | Supported |
| GPS | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou, QZSS | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou |
| NFC | Supported | Supported |
| Infrared port | Supported | Not supported |
🧭 Sensors | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| Sensors | Accelerometer Ambient light sensor Compass Face unlock Fingerprint sensor (side-mounted) Gyroscope | Accelerometer Ambient light sensor Barometer Compass Face unlock Fingerprint sensor (under display) Gesture Gyroscope Hall effect Proximity sensor UWB (Ultra Wideband) |
| Vibrating alert | Supported | Supported |
🔋 Battery | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| Battery type | LiPo: li-ion polymer (Non removable) | LiPo: li-ion polymer (Non removable) |
| Battery capacity | 5000 mAh | 5000 mAh |
| Charger, watts | 67W Wired fast charging USB Power Delivery 3.0 | 25W Wired fast charging USB Power Delivery 3.0 |
| Inductive / wireless charging | Not supported | 15W Qi wireless charging (Qi/PMA) 4.5W Reverse wireless charging |
| Talk time autonomy | feature not registered | feature not registered |
| Standby | feature not registered | feature not registered |
➕ Other features | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| Call control | Voice dialing, Voice recorder, Voice commands | Voice dialing, Voice recorder, Voice commands |
| Messaging | SMS (T9), MMS, E-mail, Push mail | SMS (T9), MMS, E-mail, Push mail |
| Hands-free calling | Supported | Supported |
| Video calling | Supported | Supported |
| Ringtones | Polyphonic and customized | Polyphonic and customized |
| Web browser | HTML, XHTML, HTML5 | HTML, XHTML, HTML5 |
| Antenna | Internal antenna | Internal antenna |
| Qwerty physical keyboard | Not supported | Not supported |
| Miscellaneous | • Colors: Black, Wave Blue, Cloud White • Protective case included | • Colors: Phantom Black, Silver, Titanium, Navy, Brown • Samsung Pay (Visa, MasterCard) • Samsung DeX • Stylus pen support |
☢️ Radiation rate | ||
| Xiaomi Poco X3 GT (256GB) | Galaxy S21 Ultra (SM-G998U1 256GB) | |
| SAR 1.6W/kg (USA, Mexico, etc.) | feature not registered | 0.77W/kg (head), 1.02W/kg (body) |
| SAR 2W/kg (Europe, UK, etc.) | feature not registered | feature not registered |