Product
Vivo X21 UD
Vivo X21 UD
Xiaomi Mi Mix 3 5G
Xiaomi Mi Mix 3 5G
Battery
Charging 18W wired 18W wired, QC4
Type Li-Ion 3200 mAh, non-removable Li-Po 3800 mAh, non-removable
Body
Build Glass front (Gorilla Glass 3), aluminum back, aluminum frame Glass front (Gorilla Glass 5), ceramic back, aluminum frame (7000 series)
Dimensions 154.5 x 74.8 x 7.4 mm (6.08 x 2.94 x 0.29 in) 157.9 x 74.7 x 9.4 mm (6.22 x 2.94 x 0.37 in)
SIM Nano-SIM + Nano-SIM Nano-SIM
Weight 156.2 g (5.50 oz) 225 g (7.94 oz)
Comms
Bluetooth 5.0, A2DP, LE 5.0, A2DP, LE, aptX HD
NFC No Yes
Positioning GPS, GLONASS GPS (L1+L5), GLONASS (L1), BDS (B1), GALILEO (E1+E5a), QZSS (L1+L5)
Radio FM radio No
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
Display
Protection Corning Gorilla Glass 3 Corning Gorilla Glass 5
Resolution 1080 x 2280 pixels, 19:9 ratio (~402 ppi density) 1080 x 2340 pixels, 19.5:9 ratio (~403 ppi density)
Size 6.28 inches, 98.4 cm2 (~85.2% screen-to-body ratio) 6.39 inches, 100.2 cm2 (~85.0% screen-to-body ratio)
Type Super AMOLED Super AMOLED, HDR
Features
Sensors Fingerprint (under display, optical), accelerometer, proximity, compass Fingerprint (rear-mounted), accelerometer, gyro, compass
  - Virtual proximity sensing
Launch
Announced 2018, March. Released 2018, March 2019, February. Released 2019, May
Status Discontinued Discontinued
Main Camera
Dual 12 MP, f/1.8, 1/2.55", 1.4µm, dual pixel PDAF 5 MP, f/2.4, (depth) 12 MP (wide), f/1.8, 1/2.55", 1.4µm, dual pixel PDAF, 4-axis OIS 12 MP (telephoto), 1/3.4", 1.0µm
Features LED flash, HDR, panorama LED flash, HDR, panorama
Video 1080p@30fps 4K@30/60fps, 1080p@30/60/240fps, 1080p@960fps; gyro-EIS
Memory
Card slot microSDXC (uses shared SIM slot) No
Internal 128GB 6GB RAM 64GB 6GB RAM, 128GB 6GB RAM
  eMMC 5.1 UFS 2.1
Misc
Colors Black, Ruby Red Sapphire Blue
Models X21UD A M1810E5GG
SAR - 1.56 W/kg (head)     1.58 W/kg (body)    
Network
2G bands GSM 850 / 900 / 1800 / 1900 GSM 850 / 900 / 1800 / 1900
3G bands HSDPA 850 / 900 / 1900 / 2100 HSDPA 850 / 900 / 1700(AWS) / 1900 / 2100
4G bands 1, 2, 3, 5, 8, 34, 38, 39, 40, 41 1, 2, 3, 4, 5, 7, 8, 20, 28, 34, 38, 39, 40, 41
5G bands - 78 NSA/Sub6
Speed HSPA 42.2/5.76 Mbps, LTE (2CA) Cat6 300/50 Mbps HSPA 42.2/5.76 Mbps, LTE (5CA) Cat18 1200/150 Mbps, 5G (2+ Gbps DL)
Technology GSM / CDMA / HSPA / LTE GSM / CDMA / HSPA / EVDO / LTE / 5G
  CDMA 800 & TD-SCDMA CDMA2000 1xEV-DO
Platform
Chipset Qualcomm SDM660 Snapdragon 660 (14 nm) Qualcomm SM8150 Snapdragon 855 (7 nm)
CPU Octa-core (4x2.2 GHz Kryo 260 Gold & 4x1.8 GHz Kryo 260 Silver) Octa-core (1x2.84 GHz Kryo 485 & 3x2.42 GHz Kryo 485 & 4x1.78 GHz Kryo 485)
GPU Adreno 512 Adreno 640
OS Android 8.1 (Oreo), Funtouch 4 Android 9.0 (Pie), MIUI 12
Selfie camera
Dual - Manual pop-up 24 MP, f/2.0, 26mm (wide), 1/2.8", 0.9µm Manual pop-up 2 MP, depth sensor
Features - LED flash, HDR
Single 12 MP, f/2.0, (wide), 1/2.8", 1.28µm -
Video 1080p@30fps 1080p@30fps
Sound
3.5mm jack Yes No
Loudspeaker Yes Yes
  32-bit/192kHz Hi-Res audio -