In depth comparison and review of Xiaomi Redmi 9 and Microsoft Surface Duo. Compare sizes, cameras, batteries, memory, and other important specifications and features to easily choose the right phone for you. Our goal is to help you uncover differences between the products and find the phone that will best fit your needs.
| DESIGN AND DIMENSIONS | Xiaomi Redmi 9 | Microsoft Surface Duo |
|---|
| Product Type | Smartphone | Smartphone | |
|---|---|---|---|
| Form Factor | Touch | Folder - dual screen | |
| Height | 163.32 mm | 145.2 mm | Xiaomi Redmi 9 has greater height than Microsoft Surface Duo. |
| Width | 77.01 mm | 93.3 mm | Microsoft Surface Duo has greater width than Xiaomi Redmi 9. |
| Depth | 9.1 mm | 9.9 mm | Xiaomi Redmi 9 is narrower than Xiaomi Redmi 9. |
| Weight | 198 g | 250 g | Xiaomi Redmi 9 is lighter than Xiaomi Redmi 9. |
| Dimensions Details | - | Unfolded - 186.9 mm x 4.8 mm x 145.2 mm | |
| Body Colour | Carbon grey | Glacier | |
| Waterproof (Water-resistant) | - | - | |
| SAR Value | 1.065 W/kg (body), 0.789 W/kg (head), 2.309 W/kg (limb) | 0.726 W/kg (head), 1.478 W/kg (body) | |
| Integrated Components | Ultra-linear speaker | - | |
| Connector Type | USB Type-C - 24 pin USB-C Headset jack - mini-phone 3.5mm |
USB Type-C - 24 pin USB-C | |
| SIM Card Type (Size) | Nano SIM | Nano SIM, Electronic SIM card (e-SIM) | |
| SIM Card Qty | Dual-SIM | Dual-SIM |
| DISPLAY | Xiaomi Redmi 9 | Microsoft Surface Duo |
|---|
| Display Type | - | OLED display | |
|---|---|---|---|
| Display Technology | - | AMOLED | |
| Foldable Display | - | Yes | |
| Display Design | - | Both directions folding | |
| Screen Size (Display Size) | 6.53" | 5.6" | Xiaomi Redmi 9 has larger screen size than Microsoft Surface Duo. |
| Screen Resolution (Display Resolution) | 2340 x 1080 pixels | 1800 x 1350 pixels | Xiaomi Redmi 9 has better screen resolution than Microsoft Surface Duo. |
| Display Format | Full HD+ | - | |
| Pixel Density | 394 ppi | 401 ppi | Microsoft Surface Duo has better pixel density than Xiaomi Redmi 9. |
| Aspect Ratio | 19.5:9 | 4:3 | |
| Max Brightness | 400 cd/m² | - | |
| Contrast Ratio | 1500:1 | - | |
| Display Enhancement Technology | Sunlight mode | - | |
| Display Features | Colour temperature adjustment, Dot Drop display, Reading mode 2.0 | PixelSense Fusion Displays | |
| Display Protection (Screen Protector) | Corning Gorilla Glass 3 (scratch resistant glass) | Corning Gorilla Glass (scratch resistant glass) |
| SECOND DISPLAY |
|---|
| Second Display Type | - | OLED display - colour | |
|---|---|---|---|
| Second Display Screen Size | - | 5.6" | |
| Second Display Resolution | - | 1800 x 1350 pixels |
| UNFOLDED DISPLAY |
|---|
| Unfolded Display Screen Size | - | 8.1 in | |
|---|---|---|---|
| Unfolded Display Resolution | - | 2700 x 1800 pixels |
| PROCESSOR | Xiaomi Redmi 9 | Microsoft Surface Duo |
|---|
| Processor Type (CPU) | MediaTek Helio G80 | Qualcomm Snapdragon 855 | |
|---|---|---|---|
| Clock Speed | 2 GHz | - | |
| Processor Core Qty | 8-core | 8-core | Both phones have the same number of phone cores. |
| 64-bit Architecture | Yes | - | Xiaomi Redmi 9 has 64-bit architecture. |
| Graphics System (GPU) | Mali-G52 MC2 | - |
| MEMORY | Xiaomi Redmi 9 | Microsoft Surface Duo |
|---|
| RAM | LPDDR4X SDRAM - 4 GB | 6 GB | Microsoft Surface Duo has more RAM than Xiaomi Redmi 9. |
|---|---|---|---|
| Internal Memory Size (Storage Capacity) | 64 GB | 128 GB | Microsoft Surface Duo has more internal memory than Xiaomi Redmi 9. |
| Memory Interface | - | UFS 3.0 | |
| Supported Flash Memory Cards (Expandable Memory) | microSD | - |
| CAMERA | Xiaomi Redmi 9 | Microsoft Surface Duo |
|---|
| MAIN CAMERA |
|---|
| Number of Main Cameras | 4 | 0 | |
|---|---|---|---|
| Sensor Resolution | 13 Megapixel | - | |
| Lens Type | Wide-angle lens | - | |
| Lens Aperture | F/2.2 | - | |
| Field of View (FoV) | 75.2 degree(s) | - | |
| Focus Adjustment | Automatic | - | |
| Special Effects | HDR, Kaleidoscope | - | |
| Camera Modes | Portrait mode | - | |
| Light Source | Flash | - | |
| Video Resolutions | 1920 x 1080 (1080p) at 30 fps, 1280 x 720 (720p) at 30 fps | - |
| SECOND CAMERA |
|---|
| Sensor Resolution (2nd Camera) | 8 Megapixel | - | |
|---|---|---|---|
| Lens Type (2nd Camera) | Ultra wide-angle lens | - | |
| Lens Aperture (2nd Camera) | F/2.2 | - | |
| Field of View (2nd Camera) | 118 degree(s) | - |
| THIRD CAMERA |
|---|
| Sensor Resolution (3rd Camera) | 5 Megapixel | - | |
|---|---|---|---|
| Lens Aperture (3rd Camera) | F/2.4 | - | |
| Camera Functions (3rd Camera) | Macro camera | - |
| FOURTH CAMERA |
|---|
| Sensor Resolution (4th Camera) | 2 Megapixel | - | |
|---|---|---|---|
| Camera Functions (4th Camera) | Depth camera | - |
| FRONT CAMERA |
|---|
| Number of Front Cameras | 1 | 1 | |
|---|---|---|---|
| Sensor Resolution (Front) | 8 Megapixel | 11 Megapixel | Microsoft Surface Duo has better front camera resolution than Xiaomi Redmi 9. |
| Lens Aperture (Front) | F/2.0 | F/2.0 | Both phones have the same front camera lens aperture. |
| Field of View (Front) | 77.8 degree(s) | 84 degree(s) | Microsoft Surface Duo has larger front lens field of view than Xiaomi Redmi 9. |
| Pixel Size (Front) | - | 1 μm | |
| Focus Adjustment | Focus free | - | |
| Special Effects (Front) | HDR | HDR | |
| Camera Modes (Front) | Portrait mode | Burst mode, Panorama, low-light shots, Portrait mode with adjustable depth control | |
| Light Source (Front) | Display flash | High CRI LED flash | |
| Video Resolutions (Front) | - | 1920 x 1080 (1080p) at 30 fps, 1920 x 1080 (1080p) at 60 fps, 3840 x 2160 (4K) at 30 fps, 3840 x 2160 (4K) at 60 fps | |
| Camera Features (Front) | Self-timer, Palm shutter | Phase Detect Auto-Focus (PDAF), FOV optimised with AI (for front and rear), dynamic range scene detection, Super-resolution zoom, super zoom up to 7x, gyro-based digital video stabilisation |
| BATTERY AND CHARGING | Xiaomi Redmi 9 | Microsoft Surface Duo |
|---|
| Battery Capacity (Battery Size) | 5020 mAh | 3577 mAh | Xiaomi Redmi 9 has larger battery capacity than Microsoft Surface Duo. |
|---|---|---|---|
| Standby Time | - | 240 hours | |
| Talk Time | 1860 minutes | 1620 minutes | Xiaomi Redmi 9 has longer battery life when making calls than Microsoft Surface Duo. |
| Run Time Details | Talk: up to 1860 min Continuous navigation: up to 19 hrs Playback (video): up to 19 hrs Playback (Music): up to 185 hrs |
Standby: up to 240 hrs Talk: up to 1620 min Playback (local video): up to 15.5 hrs |
| CELLULAR | Xiaomi Redmi 9 | Microsoft Surface Duo |
|---|
| Technology | WCDMA (UMTS) / GSM | WCDMA (UMTS) / GSM | |
|---|---|---|---|
| Mobile Broadband Generation | 4G | 4G | Both phones have the same mobile network generation. |
| Operating System | - | Android 10 | |
| Intelligent Assistant | - | Google Assistant | |
| Navigation | GPS, A-GPS, GLONASS, BeiDou | GPS, GLONASS, BeiDou, Galileo, QZSS |
| COMMUNICATIONS | Xiaomi Redmi 9 | Microsoft Surface Duo |
|---|
| Data Transmission | GPRS, EDGE, HSDPA, HSUPA, HSPA+, VoLTE, FDD-LTE, TDD-LTE | GPRS, FDD-LTE, TDD-LTE, LAA | |
|---|---|---|---|
| 2G Band | - | 850 GSM, 900 GSM, 1800 GSM, 1900 GSM | |
| 3G UMTS Band | Band 1, Band 2, Band 4, Band 5, Band 8 | Band 1, Band 2, Band 5, Band 8 | |
| 3G UMTS Frequency | 2100, 1900, 1700, 850, 900 | 2100, 1900, 850, 900 | |
| 4G LTE Band | Band 1, Band 2, Band 3, Band 4, Band 5, Band 7, Band 8, Band 20, Band 28, Band 38, Band 40, Band 41 | Band 1, Band 2, Band 3, Band 4, Band 5, Band 7, Band 8, Band 12, Band 13, Band 14, Band 19, Band 20, Band 25, Band 26, Band 28, Band 29, Band 30, Band 38, Band 39, Band 40, Band 41, Band 46, Band 66 | |
| 4G LTE Frequency | FDD 2100, FDD 1900 PCS, FDD 1800+, FDD 1700 - 2110 AWS, FDD 850, FDD 2600, FDD 900, FDD 800 DD, FDD 700 APT, TDD 2600, TDD 2300, TDD 2500 | FDD 2100, FDD 1900 PCS, FDD 1800+, FDD 1700 - 2110 AWS, FDD 850, FDD 2600, FDD 900, FDD 700a, FDD 700c, FDD 700 PS, FDD 800 upper, FDD 800 DD, FDD 1900+, FDD 850+, FDD 700 APT, FDD 700d, FDD 2300 WCS, TDD 2600, TDD 1900, TDD 2300, TDD 2500, TDD 5150, FDD 1700 - 2110 AWS-3 | |
| Wireless Interface | IEEE 802.11b/g/n | IEEE 802.11ac | |
| Bluetooth | Bluetooth 5.0 | Bluetooth 5.0 | |
| Messaging Services | SMS, MMS | - |
| MEDIA | Xiaomi Redmi 9 | Microsoft Surface Duo |
|---|
| Supported Digital Audio Standards | AAC, PCM, MP3, FLAC, AAC +, eAAC+, APE (Monkey's Audio), AMR-WB, AMR-NB | WAV, AAC, AMR, MP3, FLAC, OGG, MIDI, M4A, apt-X, IMY, RTTTL, RTX, OTA, MID | |
|---|---|---|---|
| Supported Digital Video Standards | MKV, H.264, ASP, MP4 | MKV, FLV, AVI, MOV, WMV, 3GP, TS, WebM, H.265 HEVC, MP4 | |
| Sound Enhancements | - | Qualcomm aptX audio |
| FEATURES | Xiaomi Redmi 9 | Microsoft Surface Duo |
|---|
| Phone Functions | Speakerphone, voice control, call timer, conference call, flight mode, voice dialing, vibrating alert | Speakerphone, voice control, call timer, conference call, flight mode, voice dialing, vibrating alert | |
|---|---|---|---|
| Sensors | Accelerometer, ambient light sensor, digital compass, distance sensor, infrared (IR) sensor | Proximity sensor, hall sensor, dual accelerometers, dual gyroscope, dual magnetometer, dual ambient light sensor | |
| Security Devices | Face recognition, fingerprint reader | Fingerprint reader (side) | |
| Additional Phone Features | Fast Charging, AI face unlock | MIMO technology, Fast Charging, dual microphones with noise suppression and echo cancellation, Full Duplex communication, 360° hinge, stylus support, two apps side-by-side |
| OTHERS | Xiaomi Redmi 9 | Microsoft Surface Duo |
|---|
| Included Accessories | SIM card removal tool, USB-C cable, TPU case, 10W charger | SIM card removal tool, USB-C headphones, 18W charger, Surface Duo Bumper (Glacier) |
|---|
cs
sk
de
it
es
fr
hu
pt
ru
pl
br
ro
