iPad mini (Original) 

iPad mini 2
Display Size: 7.9" 7.9"
Resolution: 1024x768 2048x1536
Pixel Density: 163 ppi  326 ppi 
Processor Speed: 1.0 GHz  1.3 GHz 
Processor Type: Apple A5 Apple A7 
Architecture: 32-Bit 64-Bit
Motion Coprocessor: None Apple M7 
RAM:  512 MB  1 GB 
Original Storage:  16, 32, 64 GB  16, 32, 64, 128 GB
Current Storage:  Used Market Only 32 GB
Data Networks:  Wi-Fi/Wi-Fi & Cellular Data  Wi-Fi/Wi-Fi & Cellular Data 
MIMO Support:  No Yes
Bluetooth:  4.0 4.0
Front Camera:  720p (1.2 MP) 720p (1.2 MP)
Rear Camera: 1080p (5 MP)  1080p (5 MP) 
A-GPS:  No/Yes No/Yes
Microphone(s):  One Two
Max Battery Life:  9-10 Hours  9-10 Hours 
Original Color Options:  White/Silver, Black/Slate White/Silver, Black/Gray 
Current Color Options:  White/Silver, Black/Gray  White/Silver, Black/Gray 
Original iOS:  iOS 6  iOS 7
Maximum iOS:  iOS 9 iOS 10
Panorama (iOS 7):  No No
Panorama (iOS 8):  No Yes
Slide Over (iOS 9):  No Yes
Split View (iOS 9):  No No
Transit (iOS 9):  No Yes
Dimensions (In):  7.87 x 5.3 x 0.28 7.87 x 5.3 x 0.29
Weight (Lbs):  0.68, 0.69  0.73, 0.75 
 

Feature iPad 2 iPad 3 iPad 4
CPU: Dual-Core Apple A5 Dual-Core Apple A5X Dual-Core Apple A6X
Graphics: PowerVR SGX543MP2 PowerVR SGX543MP4 PowerVR SGX543MP4
Display: 1024x768 2048x1536 2048x1536
Memory: 512 MB 1 GB 1 GB
Storage: 16, 32, 64 GB 16, 32, 64 GB 16, 32, 64 GB
Camera: Front-facing and 720p rear-facing 720p Front-facing and iSight 5 MP rear-facing 720p Front-facing and iSight 5 MP rear-facing
Data Rate: 3G 4G LTE 4G LTE
Wi-Fi: 802.11 a/b/g/n 802.11 a/b/g/n 802.11 a/b/g/n
Bluetooth: 2.1 + EDR 4.0 4.0
Siri: NO YES YES
Accelerometer: YES YES YES
Compass: YES YES YES
Gyroscope: YES YES YES
GPS: 3G Version Only 4G Version Only 4G Version Only