Samsung Galaxy S21 Ultra (SM-G998B 256GB) vs Xiaomi 12X (128GB)
Side by side comparison between Samsung Galaxy S21 Ultra vs Xiaomi 12X phones, differences, pros, cons and full specifications. What's the better?
,
6.8"
AMOLED
AMOLED
1440x3200
108
MP
MP
40mp
12GB
RAM
RAM
Octa-core
5000
mAh
mAh
(Non removable)
vs
6.28"
AMOLED
AMOLED
1080x2400
50
MP
MP
32mp
8GB
RAM
RAM
Octa-core
4500
mAh
mAh
(Non removable)
What's the better phone? Samsung Galaxy S21 Ultra (SM-G998B 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!
23 Advantages 
6 Advantages | 32 Common items in both devices |
| UFS 3.1 |
| Aluminum frame, glass front/back / Aluminum body, glass front, plastic back |
| HDR10+ / Dolby Vision/HDR10+ |
| 120Hz |
| PDAF: phase detection autofocus on both cameras / PDAF: phase detection autofocus |
| OIS: Optical stabilization |
| BSI sensor |
| +25 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 | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| Model | Galaxy S21 Ultra (SM-G998B 256GB) | 12X (128GB) |
| Other model names | Galaxy S21 Ultra 5G (SM-G998B Single-SIM) | Xiaomi 12X 2112123AG (Global), 2112123AC (China) |
| Country or region available |  Australia |  (Global, International) |
| Brand | Samsung | Xiaomi |
| Release date | 1/29/2021, Announced: 1/14/2021 | 12/31/2021, Announced: 12/28/2021 |
| Depth | 8.9 millimeters (0.35 inches) | 8.2 millimeters (0.32 inches) |
| Size (width x height) | 75.6 x 165.1 millimeters (2.98 x 6.5 in) | 69.9 x 152.7 millimeters (2.75 x 6.01 in) |
| Weight | 227 grams (7.95 ounces) | 176 grams (6.16 ounces) |
| Build, materials | Aluminum frame, glass front/back | Aluminum body, glass front, plastic back |
| Protection against water and others | IP68 certified: water-resistant up to 1.5 meters for 30min and dust-resistant | Not supported |
📲 Display | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| Display type | Dynamic AMOLED | AMOLED |
| Screen size | 6.8" inches | 6.28" inches |
| Screen-to-body ratio | ~89.4% (screen-to-body ratio) | ~89.2% (screen-to-body ratio) |
| Display resolution | 1440x3200 pixels (20:9) | 1080x2400 pixels (20:9) |
| Touchscreen | Capacitive Multitouch 10-points | Capacitive Multitouch |
| Pixel density (dot pitch) | 516 PPI | 419 PPI |
| Colors | 16 million | 1 billion |
| Scratch-resistant glass | Gorilla Glass Victus | Gorilla Glass Victus |
| Refresh rate | 120Hz | 120Hz |
| Display features | 1500nits[peak] HDR10+ Always-On Display | 1100nits[peak] Dolby Vision/HDR10+ DCI-P3 Touch rate: 480Hz |
🤖 Operating System | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| System version | Android 11 | Android 11 |
| Firmware update | Android 15 | Android 12 |
| User Interface | One UI 3.1 / 4.1 / 5.1 / 6.0 / 7.0 | MIUI 13 |
⚙️ Processor | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| Chipset | 64bit: Samsung Exynos 2100 (5nm) | 64bit: Qualcomm Snapdragon 870 (SM8250-AC) (7nm) |
| CPU | Octa-core, 3 processors: 1x 2.9GHz ARM Cortex-X1 (Single-core) 3x 2.8GHz ARM Cortex-A78 (Triple-core) 4x 2.2GHz ARM Cortex-A55 (Quad-core) | Octa-core, 3 processors: 1x 3.2GHz Kryo 585 (Single-core) 3x 2.42GHz Kryo 585 (Triple-core) 4x 1.8GHz Kryo 585 (Quad-core) |
| GPU graphical controller | ARM Mali-G78 MP14 (854MHz) | Qualcomm Adreno 650 (670MHz) |
| Performance (benchmark) | AnTuTu: 657150 (v8), 727634 (v9) Geekbench: 3457 (v5.2) GFXBench: 51fps (ES 3.1 onscreen) | AnTuTu: 598003 (v8), 690298 (v9) Geekbench: 3168 (v5.1) GFXBench: 47fps (ES 3.1 onscreen) |
💽 Memory and storage | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| RAM memory | 12GB LPDDR5 | 8GB LPDDR5 |
| Internal storage | 256GB (220GB available) UFS 3.1 | 128GB (103GB available) UFS 3.1 |
| External storage | Not supported | Not supported |
📶 Mobile networks | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| Dual-SIM | Dual-SIM Standby - Call active on one sim card | Dual-SIM Standby - Call active on one sim card |
| SIM card | 1 slot (Single-SIM) nano-SIM (4FF) + e-SIM | 2 slots (Dual-SIM) nano-SIM (4FF) |
| Maximum Download / Upload | 5000/1920 Mbps | 2000/1024 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, GSM 850/900/1800/1900 |
| Primary 3G network | UMTS 850/900/1700/1900/2100 | CDMA2000 1xEV-DO UMTS 800/850/900/1700/1900/2100 |
| Primary 4G network | LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 28, 32, 66) TD-LTE (38, 39, 40, 41) VoLTE | LTE Cat20 VoLTE Global version: LTE (1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 26, 28, 32, 66) TD-LTE (38, 39, 40, 41, 42, 48) China version: LTE (1, 2, 3, 4, 5, 7, 8, 18, 19, 26) TD-LTE (34, 38, 39, 40, 41, 42) |
| Primary 5G network | SA/NSA/Sub6 (1, 3, 5, 7, 8, 20, 28, 38, 40, 41, 66, 77, 78) | Global version: SA/NSA (1, 3, 5, 7, 8, 20, 28, 38, 40, 41, 66, 77, 78) China version: SA/NSA (1, 3, 5, 8, 28, 38, 40, 41, 77, 78) |
| 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 |
| Secondary 2G network | GSM 850/900/1800/1900 | GSM 850/900/1800/1900 |
| Secondary 3G network | UMTS 850/900/1700/1900/2100 | UMTS 800/850/900/1700/1900/2100 |
| Secondary 4G network | LTE Cat20 (1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 28, 32, 66) TD-LTE (38, 39, 40, 41) VoLTE | LTE Cat20 VoLTE Global version: LTE (1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 26, 28, 32, 66) TD-LTE (38, 39, 40, 41, 42, 48) China version: LTE (1, 2, 3, 4, 5, 7, 8, 18, 19, 26) TD-LTE (34, 38, 39, 40, 41, 42) |
| Secondary data network | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA | GPRS, EDGE, UMTS, HSDPA, HSUPA, HSPA+, TD-LTE, LTE, LTE-A, SA/NSA |
📷 Camera | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| Back camera (main camera) | (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 | (triple camera) 50 megapixels 13MP ultrawide f/2.412mm123°1/3.06"1.12µm 5MP telephoto macro f/2.450mmAF |
| Main camera resolution | 12000x9000 pixels | 8160x6120 pixels |
| Video recording (primary) | 8K UHD (7680x4320) 24 fps | 8K UHD (7680x4320) 24 fps |
| Flash | LED flash | Dual-LED flash |
| Focal aperture | f/1.8 (aperture) | f/1.9 (aperture) |
| Focal length | 26mm (lens) | 26mm (lens) |
| Sensor size | 1/1.33" inches | 1/1.56" inches |
| Pixel size | 1.8µm pixel | 1µm pixel |
| Autofocus | PDAF: phase detection autofocus on both cameras | PDAF: phase detection autofocus |
| Touch focus | Supported | Supported |
| Image stabilization | OIS: Optical stabilization | OIS: Optical stabilization |
| Zoom | Digital and optical zoom | Only digital zoom |
| Face/smile detection | Face detection, Smile detection | Face detection, Smile detection |
| BSI sensor | Supported | Supported |
| HDR | HDR photo/video on both cameras | HDR photo/video on both cameras |
| Camera extras | 4K@60fps 1080p@240fps 720p@960fps | 4K@60fps 1080p@960fps Sony IMX766 |
📸 Front camera | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| Front camera (secondary) | 40 megapixels | 32 megapixels |
| Front camera resolution | 7296x5472 pixels | 6528x4896 pixels |
| Video recording (secondary) | 4K UHD (3840x2160) | Full HD (1920x1080) |
| Front flash | Not supported | Not supported |
| Focal aperture | f/2.2 (aperture) | f/2.5 (aperture) |
| Focal length | 26mm (lens) | 26mm (lens) |
| Sensor size | 1/2.8" inches | feature not registered |
| Pixel size | 0.7µm pixel | 0.7µm pixel |
🔉 Sound and multimedia | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| Loudspeaker | Stereo sound 32-bit/384kHz Dolby Atmos Tuned by AKG | Stereo sound with dual speakers 24-bit/192kHz Dolby Atmos Tuned by Harman Kardon |
| Active noise cancellation | 3 microphones | 2 microphones or more |
| Radio | FM | Not supported |
| 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 | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| USB | USB 3.2 Type-C, USB OTG On-The-Go | USB 2.0 Type-C, USB OTG On-The-Go |
| Audio output | Type-C reversible connector | 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 | Supported | Not supported |
| GPS | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou | A-GPS, GeoTagging, GLONASS, GALILEO, BeiDou, QZSS, NavIC |
| NFC | Supported | Supported |
| Infrared port | Not supported | Supported |
🧭 Sensors | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| Sensors | Accelerometer Ambient light sensor Barometer Compass Face unlock Fingerprint sensor (under display) Gesture Gyroscope Hall effect Proximity sensor UWB (Ultra Wideband) | Accelerometer Ambient light sensor Compass Face unlock Fingerprint sensor (under display) Gyroscope Proximity sensor |
| Vibrating alert | Supported | Supported |
🔋 Battery | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| Battery type | LiPo: li-ion polymer (Non removable) | LiPo: li-ion polymer (Non removable) |
| Battery capacity | 5000 mAh | 4500 mAh |
| Charger, watts | 25W Wired fast charging USB Power Delivery 3.0 | 67W Wired fast charging Quick Charge 4 USB Power Delivery 3.0 |
| Inductive / wireless charging | 15W Qi wireless charging (Qi/PMA) 4.5W Reverse wireless charging | Not supported |
| Talk time autonomy | feature not registered | feature not registered |
| Standby | feature not registered | feature not registered |
➕ Other features | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| 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: Phantom Black, Silver, Titanium, Navy, Brown • Samsung Pay (Visa, MasterCard) • Samsung DeX • Stylus pen support | • Colors: Gray, Blue, Purple • LiquidCool |
☢️ Radiation rate | ||
| Galaxy S21 Ultra (SM-G998B 256GB) | Xiaomi 12X (128GB) | |
| SAR 1.6W/kg (USA, Mexico, etc.) | 0.24W/kg (head), 0.72W/kg (body) | feature not registered |
| SAR 2W/kg (Europe, UK, etc.) | 0.714W/kg (head), 1.58W/kg (body) | 0.59W/kg (head), 1W/kg (body) |