Product
Vivo X20
Vivo X20
Xiaomi Mi Max 3
Xiaomi Mi Max 3
Battery
Charging - 18W wired, QC3
Type Li-Ion 3250 mAh, non-removable Li-Ion 5500 mAh, non-removable
Body
Build Glass front, aluminum back, aluminum frame Glass front, aluminum back, aluminum frame
Dimensions 155.9 x 75.2 x 7.2 mm (6.14 x 2.96 x 0.28 in) 176.2 x 87.4 x 8 mm (6.94 x 3.44 x 0.31 in)
SIM Nano-SIM + Nano-SIM Nano-SIM + Nano-SIM
Weight 159 g (5.61 oz) 221 g (7.80 oz)
Comms
Bluetooth 5.0, A2DP, LE 5.0, A2DP, LE
Infrared port - Yes
NFC No No
Positioning GPS GPS, GLONASS, BDS
Radio No FM radio
USB microUSB 2.0, OTG USB Type-C
WLAN Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct, DLNA
Display
Protection - To be confirmed
Resolution 1080 x 2160 pixels, 18:9 ratio (~402 ppi density) 1080 x 2160 pixels, 18:9 ratio (~350 ppi density)
Size 6.01 inches, 93.2 cm2 (~79.5% screen-to-body ratio) 6.9 inches, 122.9 cm2 (~79.8% screen-to-body ratio)
Type Super AMOLED IPS LCD
Features
Sensors Fingerprint (rear-mounted), accelerometer, gyro, proximity, compass Fingerprint (rear-mounted), accelerometer, gyro, proximity, compass
Launch
Announced 2017, September. Released 2017, October 2018, July. Released 2018, July
Status Discontinued Discontinued
Main Camera
Dual 12 MP, f/1.8, AF 5 MP, f/2.4, (depth) 12 MP, f/1.9, 1/2.55", 1.4µm, dual pixel PDAF 5 MP, f/2.2, (depth)
Features LED flash, HDR, panorama Dual-LED flash, HDR, panorama
Video 1080p@30fps 4K@30fps, 720p/1080p@30fps (gyro-EIS), 720p@120fps
Memory
Card slot microSDXC (uses shared SIM slot) microSDXC (uses shared SIM slot)
Internal 64GB 4GB RAM 64GB 4GB RAM, 128GB 6GB RAM
  eMMC 5.1 eMMC 5.1
Misc
Colors Matte Black, Black/Gold, Gold, Rose gold, Blue, Pink Black, Champagne Gold, Blue
Models X20A, 1721 M1804E4A
SAR - 1.58 W/kg (head)     1.42 W/kg (body)    
Network
2G bands GSM 900 / 1800 - SIM 1 & SIM 2 GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2
3G bands HSDPA 850 / 900 / 1900 / 2100 HSDPA 850 / 900 / 1900 / 2100
4G bands 1, 2, 3, 5, 7, 8, 34, 38, 39, 40, 41 1, 3, 4, 5, 7, 8, 20, 34, 38, 39, 40, 41
Speed HSPA 42.2/5.76 Mbps, LTE (2CA) Cat6 300/50 Mbps HSPA, LTE
Technology GSM / CDMA / HSPA / LTE GSM / CDMA / HSPA / EVDO / LTE
  1, 2, 3, 4, 5, 8, - X20A CDMA2000 1xEV-DO
Our Tests
Audio quality - Noise -93.7dB / Crosstalk -94.0dB
Battery (old) - Endurance rating 115h
Camera - Photo / Video
Display - Contrast ratio: 1462 (nominal), 3.061 (sunlight)
Loudspeaker - Voice 68dB / Noise 71dB / Ring 83dB
Performance - AnTuTu: 119229 (v7) GeekBench: 4907 (v4.4) GFXBench: 6fps (ES 3.1 onscreen)
Platform
Chipset Qualcomm SDM660 Snapdragon 660 (14 nm) Qualcomm SDM636 Snapdragon 636 (14 nm)
CPU Octa-core (4x2.2 GHz Kryo 260 Gold & 4x1.8 GHz Kryo 260 Silver) Octa-core (4x1.8 GHz Kryo 260 Gold & 4x1.6 GHz Kryo 260 Silver)
GPU Adreno 512 Adreno 509
OS Android 7.1.1 (Nougat), upgradable to Android 8.0 (Oreo), Funtouch 3.2 Android 8.1 (Oreo), upgradable to Android 10, MIUI 12
Selfie camera
Single 12 MP, f/2.0, (wide), 1/2.8", 1.28µm 8 MP, f/2.0, 1/4.0", 1.12µm
Video 1080p@30fps
Sound
3.5mm jack Yes Yes
Loudspeaker Yes Yes, with stereo speakers
  32-bit/192kHz audio -