📱 Model features |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| Model | Galaxy Watch (42mm SM-R815W) | Amazfit T-Rex |
| Other model names | Galaxy Watch 42mm (4G LTE) SM-R815WZDAXAC, Samsung Galileo | Mi Amazfit TRex |
| Country or region available | 
Canada | 
(Global, International) |
| Brand | Samsung | Xiaomi |
| Release date | 8/1/2018 | 1/9/2020, Announced: 1/1/2020 |
| Depth | 12.7 millimeters (0.5 inches) | 13.5 millimeters (0.53 inches) |
| Size (width x height) | 41.9 x 45.7 millimeters (1.65 x 1.8 in) | 47.47 x 47.47 millimeters (1.87 x 1.87 in) |
| Weight | 49 grams (1.72 ounces) | 58 grams (2.03 ounces) |
| Build, materials | Stainless steel body, glass front | Plastic body, glass front |
| Protection against water and others | 5 ATM: 50 meters waterproof.
MIL-STD-810G military certified: salt, dust, humidity, rain, vibration, solar radiation, transport and thermal shock resistant. | 5 ATM: 50 meters waterproof |
🤖 Operating System |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| System version | Tizen 4.0 | Proprietary OS |
| Firmware update | feature not registered | feature not registered |
| User Interface | feature not registered | RTOS |
⚙️ Processor |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| Chipset | 64bit: Samsung Exynos 9 Dual 9110 (10nm) | 32bit |
| CPU | Dual-core, 1 processor:
2x 1.15GHz ARM Cortex-A53 (Dual-core) | Single-core, 1 processor:
Single-core |
| GPU graphical controller | ARM Mali-T720 MP1 | feature not registered |
| Performance (benchmark) | feature not registered | feature not registered |
💽 Memory and storage |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| RAM memory | 1.5GB LPDDR3 | 512MB LPDDR3 |
| Internal storage | 4GB (1.5GB available)
eMMC | 4GB (2GB available)
eMCP |
| External storage | Not supported | Not supported |
📲 Display |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| Display type | Super AMOLED | AMOLED |
| Screen size | 1.2" inches | 1.3" inches |
| Screen-to-body ratio | ~24.3% (screen-to-body ratio) | ~24.2% (screen-to-body ratio) |
| Display resolution | 360x360 pixels (1:1) | 360x360 pixels |
| Touchscreen | Capacitive Multitouch | Capacitive Multitouch |
| Pixel density (dot pitch) | 424 PPI | 392 PPI |
| Colors | 16 million | 16 million |
| Scratch-resistant glass | Gorilla Glass DX+ | Gorilla Glass 3 |
| Refresh rate | feature not registered | 60Hz |
| Display features | Not supported | Not supported |
📶 Mobile networks |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| Dual-SIM | Not supported | Not supported |
| SIM card | 1 slot (Single-SIM)
e-SIM (Eletronic) | Not supported |
| Maximum Download / Upload | 10 Mbps | feature not registered |
| Network technology | 3G, 4G | feature not registered |
| Frequency, bands | Expand band detailsCollapse details |
| GSM MHz band | Not supported | Not supported |
| Primary 2G network | Not supported | Not supported |
| Primary 3G network | UMTS 850/1700/1900 | Not supported |
| Primary 4G network | LTE (Bands 2,4,5,12,13,25,26,66) | Not supported |
| Primary 5G network | Not supported | Not supported |
| Primary data network | UMTS, HSDPA, HSUPA, HSPA+, LTE | Not supported |
| Secondary 2G network | Not supported | Not supported |
| Secondary 3G network | Not supported | Not supported |
| Secondary 4G network | Not supported | Not supported |
| Secondary data network | Not supported | Not supported |
📷 Camera |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| Back camera (main camera) | Not supported | Not supported |
| Main camera resolution | Not supported | Not supported |
| Video recording (primary) | Not supported | Not supported |
| Flash | Not supported | Not supported |
| Focal aperture | feature not registered | feature not registered |
| Focal length | feature not registered | feature not registered |
| Sensor size | feature not registered | feature not registered |
| Pixel size | feature not registered | feature not registered |
| Autofocus | Not supported | Not supported |
| Touch focus | Not supported | Not supported |
| Image stabilization | Not supported | Not supported |
| Zoom | Not supported | Not supported |
| Face/smile detection | Not supported | Not supported |
| BSI sensor | Not supported | Not supported |
| HDR | Not supported | Not supported |
| Camera extras | feature not registered | feature not registered |
📸 Front camera |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| Front camera (secondary) | Not supported | Not supported |
| Front camera resolution | Not supported | Not supported |
| Video recording (secondary) | Not supported | Not supported |
| Front flash | Not supported | Not supported |
| Focal aperture | feature not registered | feature not registered |
| Focal length | feature not registered | feature not registered |
| Sensor size | feature not registered | feature not registered |
| Pixel size | feature not registered | feature not registered |
🔉 Sound and multimedia |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| Loudspeaker | Supported | feature not registered |
| Active noise cancellation | Not supported | Not supported |
| Radio | Not supported | Not supported |
| TV | Not supported | Not supported |
| Video formats | MP4 | feature not registered |
| Audio formats | MP3, WAV, WMA, OGG, eAAC+ | feature not registered |
🔌 Connectivity |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| USB | Not supported | Not supported |
| Audio output | Not supported | Not supported |
| TV output | Not supported | Not supported |
| Bluetooth | 4.2 + A2DP | 5.0 + A2DP/LE |
| WiFi | 802.11 b/g/n (2.4GHz) | Not supported |
| DLNA | Not supported | Not supported |
| GPS | A-GPS, GeoTagging, GLONASS | A-GPS, GeoTagging, GLONASS |
| NFC | Supported | Not supported |
| Infrared port | Not supported | Not supported |
🧭 Sensors |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| Sensors | Accelerometer
Ambient Light sensor
Barometer
Gyroscope
Heart rate
Pedometer | Accelerometer
Ambient Light sensor
Compass
Heart rate
Pedometer
SpO2 |
| Vibrating alert | Supported | Supported |
🔋 Battery |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| Battery type | Li-Ion: Lithium-Ion (Non removable) | LiPo: Li-Ion polymer (Non removable) |
| Battery capacity | 270 mAh | 390 mAh |
| Charger, watts | 3.5W (5V/0.7A) Wired charging | Wired charging |
| Wireless charging | Qi wireless charging | Magnetic charging (dock) |
| Talk time autonomy | feature not registered | 20 hours |
| Standby | 72 hours (3 days) | 480 hours (20 days) |
➕ Other features |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| Call control | Voice dialing, Voice recorder, Voice commands | Not supported |
| Messaging | SMS (T9), MMS, E-mail, Push mail | SMS (T9), E-mail |
| Hands-free calling | Supported | Not supported |
| Video calling | Not supported | Not supported |
| Ringtones | Polyphonic and customized | feature not registered |
| Web browser | Not supported | Not supported |
| Antenna | Internal antenna | feature not registered |
| Qwerty physical keyboard | Not supported | Not supported |
| Miscellaneous | • Colors: Midnight Black, Rose Gold
• Straps: Black, Grey, Red, Yellow, Purple, Pink, Brown
• Compatible with standard 20mm straps
• Always-on display
• Rotating bezel
• Samsung Pay
• Compatible with Bell and Telus carriers | • Colors: Black, Gray, Camouflage, Army green, Khaki
• Watch band: 22mm
• BioTracker PPG
• 14 sports mode
• AppZepp app
• Compatible with Android 5.0/iOS 10 and above |
☢️ Radiation rate |
| Samsung Galaxy Watch (42mm SM-R815W) | Xiaomi Amazfit T-Rex |
| SAR 1.6W/kg (USA, Mexico, etc.) | 0.961W/kg (head), 1.786W/kg (body) | feature not registered |
| SAR 2W/kg (Europe, UK, etc.) | feature not registered | feature not registered |