In depth comparison and review of Xiaomi Redmi 9 and Microsoft Surface Duo 2. 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 2 |
|---|
| 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 2. |
| Width | 77.01 mm | 92.1 mm | Microsoft Surface Duo 2 has greater width than Xiaomi Redmi 9. |
| Depth | 9.1 mm | 11 mm | Xiaomi Redmi 9 is narrower than Xiaomi Redmi 9. |
| Weight | 198 g | 284 g | Xiaomi Redmi 9 is lighter than Xiaomi Redmi 9. |
| Dimensions Details | - | Unfolded - 184.5 mm x 5.5 mm x 145.2 mm | |
| Body Colour | Carbon grey | Glacier | Obsidian | |
| Body Material | - | Corning Gorilla Glass | |
| Waterproof (Water-resistant) | - | - | |
| Repairability Index | - | 3.9 (out of 10) | |
| 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 2 |
|---|
| Display Type | - | OLED display | |
|---|---|---|---|
| Display Technology | - | AMOLED | |
| Foldable Display | - | Yes | |
| Display Design | - | Both directions folding | |
| Screen Size (Display Size) | 6.53" | 5.8" | Xiaomi Redmi 9 has larger screen size than Microsoft Surface Duo 2. |
| Screen Resolution (Display Resolution) | 2340 x 1080 pixels | 1344 x 1892 pixels | Microsoft Surface Duo 2 has better screen resolution than Xiaomi Redmi 9. |
| Display Format | Full HD+ | - | |
| Pixel Density | 394 ppi | 401 ppi | Microsoft Surface Duo 2 has better pixel density than Xiaomi Redmi 9. |
| Aspect Ratio | 19.5:9 | 13:9 | |
| Max Brightness | 400 cd/m² | 800 cd/m² | Microsoft Surface Duo 2 has better display brightness than Xiaomi Redmi 9. |
| Contrast Ratio | 1500:1 | - | |
| HDR | - | Yes | Microsoft Surface Duo 2 has HDR. |
| Display Enhancement Technology | Sunlight mode | - | |
| Display Refresh Rate | - | 90 Hz | |
| Display Features | Colour temperature adjustment, Dot Drop display, Reading mode 2.0 | DCI-P3 Wide colour gamut, 100% sRGB, Dual PixelSense Fusion Displays | |
| Display Protection (Screen Protector) | Corning Gorilla Glass 3 (scratch resistant glass) | Corning Gorilla Glass Victus (scratch resistant glass) |
| SECOND DISPLAY |
|---|
| Second Display Type | - | OLED display - colour | |
|---|---|---|---|
| Second Display Screen Size | - | 5.8" | |
| Second Display Resolution | - | 1344 x 1892 pixels |
| UNFOLDED DISPLAY |
|---|
| Unfolded Display Screen Size | - | 8.3 in | |
|---|---|---|---|
| Unfolded Display Resolution | - | 2688 x 1892 pixels |
| PROCESSOR | Xiaomi Redmi 9 | Microsoft Surface Duo 2 |
|---|
| Processor Type (CPU) | MediaTek Helio G80 | Qualcomm Snapdragon 888 5G | |
|---|---|---|---|
| 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 2 |
|---|
| RAM | LPDDR4X SDRAM - 4 GB | LPDDR5 SDRAM - 8 GB | Microsoft Surface Duo 2 has more RAM than Xiaomi Redmi 9. |
|---|---|---|---|
| Internal Memory Size (Storage Capacity) | 64 GB | 128 GB | Microsoft Surface Duo 2 has more internal memory than Xiaomi Redmi 9. |
| Supported Flash Memory Cards (Expandable Memory) | microSD | - |
| CAMERA | Xiaomi Redmi 9 | Microsoft Surface Duo 2 |
|---|
| MAIN CAMERA |
|---|
| Number of Main Cameras | 4 | 3 | |
|---|---|---|---|
| Sensor Resolution | 13 Megapixel | 12 Megapixel | Xiaomi Redmi 9 has better camera resolution than Microsoft Surface Duo 2. |
| Lens Type | Wide-angle lens | - | |
| Lens Aperture | F/2.2 | F/1.7 | Microsoft Surface Duo 2 has better lens aperture than Xiaomi Redmi 9. |
| Field of View (FoV) | 75.2 degree(s) | - | |
| Pixel Size | - | 1.4 μm | |
| Optical Image Stabiliser (OIS) | - | Optical Image Stabiliser (OIS) | Microsoft Surface Duo 2 has optical stabilisation. |
| Focus Adjustment | Automatic | - | |
| Digital Zoom | - | 10x | |
| Special Effects | HDR, Kaleidoscope | HDR | |
| Camera Modes | Portrait mode | Night mode, Auto mode, low-light shots, Panorama mode with wide dynamic range, slow motion video at 120 or 240fps | |
| Light Source | Flash | Dual LED flash | |
| Video Resolutions | 1920 x 1080 (1080p) at 30 fps, 1280 x 720 (720p) at 30 fps | 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 (Functions) | - | Dual Pixel Phase Detect Auto-Focus (PDAF), Smooth Zoom, HEVC (High Efficiency Video coding), HDR video recording, multi-frame photo capture, dynamic range scene detection |
| SECOND CAMERA |
|---|
| Sensor Resolution (2nd Camera) | 8 Megapixel | 12 Megapixel | Microsoft Surface Duo 2 has better second camera resolution than Xiaomi Redmi 9. |
|---|---|---|---|
| Lens Type (2nd Camera) | Ultra wide-angle lens | Telephoto lens | |
| Lens Aperture (2nd Camera) | F/2.2 | F/2.4 | Xiaomi Redmi 9 has better second camera lens aperture than Xiaomi Redmi 9. |
| Field of View (2nd Camera) | 118 degree(s) | - | |
| Pixel Size (2nd Camera) | - | 1 μm | |
| Optical Image Stabiliser (OIS) | - | Optical Image Stabiliser (OIS) | Microsoft Surface Duo 2 has optical stabilisation of the second camera. |
| Optical Zoom | - | 2x | |
| Camera Features (2nd Camera) | - | Phase Detect Auto-Focus (PDAF) |
| THIRD CAMERA |
|---|
| Sensor Resolution (3rd Camera) | 5 Megapixel | 16 Megapixel | Microsoft Surface Duo 2 has higher resolution third camera than Xiaomi Redmi 9. |
|---|---|---|---|
| Lens Type (3rd Camera) | - | Ultra wide-angle lens | |
| Lens Aperture (3rd Camera) | F/2.4 | F/2.2 | Microsoft Surface Duo 2 has better third camera lens aperture than Xiaomi Redmi 9. |
| Field of View (3rd Camera) | - | 110 degree(s) | |
| Pixel Size (3rd Camera) | - | 1 μm | |
| Camera Functions (3rd Camera) | Macro camera | - | |
| Camera Features (3rd Camera) | - | Field of view, distortion correction |
| 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 | 12 Megapixel | Microsoft Surface Duo 2 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) | - | |
| Pixel Size (Front) | - | 1 μm | |
| Focus Adjustment | Focus free | - | |
| Special Effects (Front) | HDR | - | |
| Camera Modes (Front) | Portrait mode | - | |
| Light Source (Front) | Display flash | - | |
| Camera Features (Front) | Self-timer, Palm shutter | - |
| BATTERY AND CHARGING | Xiaomi Redmi 9 | Microsoft Surface Duo 2 |
|---|
| Battery Capacity (Battery Size) | 5020 mAh | 4449 mAh | Xiaomi Redmi 9 has larger battery capacity than Microsoft Surface Duo 2. |
|---|---|---|---|
| Talk Time | 1860 minutes | 1680 minutes | Xiaomi Redmi 9 has longer battery life when making calls than Microsoft Surface Duo 2. |
| 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 |
Talk: up to 1680 min Playback (local video): up to 15.5 hrs |
| CELLULAR | Xiaomi Redmi 9 | Microsoft Surface Duo 2 |
|---|
| Technology | WCDMA (UMTS) / GSM | WCDMA (UMTS) / GSM | |
|---|---|---|---|
| Mobile Broadband Generation | 4G | 5G | Microsoft Surface Duo 2 has more advanced generation mobile network. |
| Operating System | - | Android 11 | |
| Intelligent Assistant | - | Google Assistant | |
| Navigation | GPS, A-GPS, GLONASS, BeiDou | GPS, GLONASS, BeiDou, Galileo, QZSS |
| COMMUNICATIONS | Xiaomi Redmi 9 | Microsoft Surface Duo 2 |
|---|
| Data Transmission | GPRS, EDGE, HSDPA, HSUPA, HSPA+, VoLTE, FDD-LTE, TDD-LTE | GPRS, FDD-LTE, TDD-LTE, Gigabit LTE, LAA, 5G NR FR1 | |
|---|---|---|---|
| 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 42, Band 46, Band 48, Band 66, Band 71 | |
| 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 3500, TDD 5150, TDD 3600, FDD 1700 - 2110 AWS-3, FDD 600 | |
| 5G NR Band | - | N1, n2, n3, n5, n7, n20, n28, n38, n41, n66, n71, n77, n78, n79, n25 | |
| 5G NR Frequency | - | FDD 2100, FDD 1900PCS, FDD 1800, FDD 850, FDD 2600, FDD 800, FDD 700APT, TDD TD 2600, TDD TD 2500, FDD AWS-3, FDD 600, TDD TD 3700, TDD TD 3500, TDD TD 4500, FDD 1900 | |
| Wireless Interface | IEEE 802.11b/g/n | IEEE 802.11ax | |
| Bluetooth | Bluetooth 5.0 | Bluetooth 5.1 | |
| NFC | - | Yes | Microsoft Surface Duo 2 has NFC reader for mobile payments. |
| Messaging Services | SMS, MMS | - |
| MEDIA | Xiaomi Redmi 9 | Microsoft Surface Duo 2 |
|---|
| 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, RTX, OTA, MID, TWS, RTTL | |
|---|---|---|---|
| Supported Digital Video Standards | MKV, H.264, ASP, MP4 | MKV, FLV, AVI, MOV, MPEG-4, WMV, ASF, 3GP, H.264, TS, M2TS, WebM, HEVC, 3G2, HEIF, H.265 HEVC, HEIC | |
| Sound Enhancements | - | Qualcomm aptX HD audio, Qualcomm aptX Classic |
| FEATURES | Xiaomi Redmi 9 | Microsoft Surface Duo 2 |
|---|
| 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 | Hall sensor, Time of Flight (ToF), dual accelerometers, dual gyroscope, dual magnetometer, dual ambient light sensor, dual proximity sensor | |
| Security Devices | Face recognition, fingerprint reader | Fingerprint reader (side) | |
| Additional Phone Features | Fast Charging, AI face unlock | MIMO technology, Fast Charging, dual battery, Full Duplex communication, dual microphones with AI-based noise suppression and acoustic echo cancellation |
| OTHERS | Xiaomi Redmi 9 | Microsoft Surface Duo 2 |
|---|
| Included Accessories | SIM card removal tool, USB-C cable, TPU case, 10W charger | SIM card removal tool, USB-C headset, Surface Duo 2 USB-C cable | |
|---|---|---|---|
| Compliant Standards | - | HEARING AID M4/T3 |
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