vs
8.4Display7.4
8.3Battery life8.4
4.9Health tracking9.4
9.4Sports & outdoor7.2
8.4Build & durability9.6
Dimensions
Size comparison
T-Rex 3Descent Mk3i 51mm
| T-Rex 3 | Descent Mk3i 51mm | Difference | |
|---|---|---|---|
| Height | 48.5 mm | 51 mm | −2.5 mm |
| Width | 48.5 mm | 51 mm | −2.5 mm |
| Thickness | 13.8 mm | 16.4 mm | −2.6 mm |
| Weight | 68 g | 78 g | −10 g |
Drawn to the same scale from the official dimensions (front and side).
Why is T-Rex 3 better than Descent Mk3i 51mm?
- Battery life (smartwatch mode)27 days vs 25 days+8%
- Weight68.3 g vs 77.8 g+14%
- Sport profiles177 vs 98+81%
- Screen size1.5″ vs 1.4″+7%
- Battery saver mode40 days vs 31 days+29%
- Thickness13.8 mm vs 16.4 mm+19%
- Resolution (width)480 px vs 454 px+6%
Why is Descent Mk3i 51mm better than T-Rex 3?
- Water resistance10 ATM vs 20 ATM2×
Specifications
Side by side
| Design & durability | ||
| Case size | 48 mm | 51 mm |
| Weight | 68.3 g | 77.8 g |
| Thickness | 13.8 mm | 16.4 mm |
| Height | 48.5 mm | 51 mm |
| Width | 48.5 mm | 51 mm |
| Case material | Stainless steel | Titanium |
| Sapphire crystal | — | Yes |
| Lens / cover glass | Gorilla Glass | sapphire crystal |
| Strap material | — | silicone or DLC coated titanium |
| Water resistance | 10 ATM | 20 ATM |
| Water rating (maker) | — | Dive (200 meters) |
| Rated dive depth | — | 200 m |
| Display | ||
| Screen size | 1.5″ | 1.4″ |
| Display technology | AMOLED | AMOLED |
| Panel | AMOLED | AMOLED |
| AMOLED / OLED display | Yes | Yes |
| Touchscreen | Yes | Yes |
| Resolution (width) | 480 px | 454 px |
| Resolution (height) | 480 px | 454 px |
| Pixel density | 322 ppi | 324 ppi |
| Battery | ||
| Battery life (smartwatch mode) | 27 days | 25 days |
| Battery life with always-on display | — | 10 days |
| Battery saver mode | 40 days | 31 days |
| GPS battery life | — | 76 h |
| GPS battery life (dual-band) | — | 48 h |
| Battery capacity | 700 mAh | — |
| Wireless charging | — | No |
| Charging | Magnetic charging base | Garmin proprietary clip charger |
| Health sensors | ||
| Optical heart rate | Yes | Yes |
| Blood oxygen (SpO2) | Yes | Yes |
| Skin temperature | — | Yes |
| Temperature sensor | Yes | Yes |
| HRV tracking | — | Yes |
| Sleep tracking | Yes | Yes |
| Sensors | — | GPS, GLONASS, Galileo, SatIQ technology, Elevate wrist heart rate monitor, Pulse Ox blood oxygen saturation monitor, Barometric altimeter, Compass, Gyroscope, Accelerometer, Thermometer, Ambient light sensor, Depth sensor |
| Sports & navigation | ||
| Built-in GPS | Yes | Yes |
| Dual-band GPS | Yes | Yes |
| Satellite systems | — | GLONASS, GALILEO |
| Offline maps | Yes | Yes |
| Barometric altimeter | Yes | Yes |
| Compass | Yes | Yes |
| Multisport / triathlon mode | — | Yes |
| Sport profiles | 177 | 98 |
| Dive mode | — | Yes |
| LED flashlight | — | Yes |
| Connectivity | ||
| NFC payments | — | Yes |
| Wi-Fi | Wi-Fi 4 | Wi-Fi 4 |
| Bluetooth | 5.2 | — |
| ANT+ sensors | — | Yes |
| Smart features | ||
| Microphone | Yes | — |
| Voice assistant | Yes | — |
| Music on the watch | Yes | Yes |
| Storage | — | 32 GB |
| Third-party apps | — | Yes |
| Platform | ||
| Operating system | — | Garmin OS |
| Platform | Proprietary | Proprietary |
| Works with | iOS, Android | iOS, Android |
