Product
Vivo X21i
Vivo X21i
Xiaomi Black Shark
Xiaomi Black Shark
Battery
Charging 18W wired 18W wired, QC3
Type Li-Ion 3425 mAh, non-removable Li-Ion 4000 mAh, non-removable
Body
Build - Glass front, aluminum back, aluminum frame
Dimensions 154.4 x 75 x 7 mm (6.08 x 2.95 x 0.28 in) 161.6 x 75.4 x 9.3 mm (6.36 x 2.97 x 0.37 in)
SIM Nano-SIM + Nano-SIM Nano-SIM + Nano-SIM
Weight 159 g (5.61 oz) 190 g (6.70 oz)
Comms
Bluetooth 5.0, A2DP, LE 5.0, A2DP, aptX HD, LE
NFC No No
Positioning GPS, GLONASS GPS, GLONASS, BDS
Radio FM radio No
USB microUSB 2.0, OTG USB Type-C 2.0
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
Resolution 1080 x 2280 pixels, 19:9 ratio (~402 ppi density) 1080 x 2160 pixels, 18:9 ratio (~403 ppi density)
Size 6.28 inches, 98.4 cm2 (~85.0% screen-to-body ratio) 5.99 inches, 92.6 cm2 (~76.0% screen-to-body ratio)
Type Super AMOLED IPS LCD
Features
Sensors Fingerprint (rear-mounted), accelerometer, proximity, compass Fingerprint (front-mounted), accelerometer, gyro, proximity, compass
Launch
Announced 2018, May. Released 2018, May 2018, April. Released 2018, April
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, f/1.8, 1/2.9", 1.25µm, dual pixel PDAF 20 MP, f/1.8, 1.0µm, AF, 2x optical zoom
Features LED flash, HDR, panorama Dual-LED dual-tone flash, HDR, panorama
Video 1080p@30fps 4K@30fps, 1080p@30fps, 720p@120fps
Memory
Card slot microSDXC (uses shared SIM slot) No
Internal 64GB 6GB RAM, 128GB 4GB RAM 64GB 6GB RAM, 128GB 8GB RAM
  eMMC 5.1 UFS 2.1
Misc
Colors Black, Aurora White, Ruby Red, Night Purple Black, Gray, Royal Blue
Models X21i A SKR-H0, SKR-A0, SHARK KSR-H0
Network
2G bands GSM 850 / 900 / 1800 / 1900 GSM 850 / 900 / 1800 / 1900
3G bands HSDPA 850 / 900 / 2100 HSDPA 850 / 900 / 1900 / 2100
4G bands 1, 3, 4, 5, 8, 38, 39, 40, 41 1, 3, 4, 5, 7, 8, 12, 34, 38, 39, 40, 41
Speed HSPA, LTE HSPA 42.2/5.76 Mbps, LTE (3CA) Cat16 1024/150 Mbps
Technology GSM / CDMA / HSPA / LTE GSM / CDMA / HSPA / EVDO / LTE
  CDMA 800 & TD-SCDMA CDMA2000 1xEV-DO
Platform
Chipset Mediatek MT6771 Helio P60 (12 nm) Qualcomm SDM845 Snapdragon 845 (10 nm)
CPU Octa-core (4x2.0 GHz Cortex-A73 & 4x2.0 GHz Cortex-A53) Octa-core (4x2.8 GHz Kryo 385 Gold & 4x1.8 GHz Kryo 385 Silver)
GPU Mali-G72 MP3 Adreno 630
OS Android 8.1 (Oreo), Funtouch 4 Android 8.0 (Oreo)
Selfie camera
Single 24 MP, f/2.0, 26mm (wide), 1/2.8", 0.9µm 20 MP, f/2.2, (wide), 1/2.8", 1.0µm
Video 1080p@30fps
Sound
3.5mm jack Yes No
Loudspeaker Yes Yes, with stereo speakers
  32-bit/192kHz Hi-Res audio -