iMac 21.5-inchiMac 21.5-inch with Retina DisplayiMac 27.5-inch with Retina Display

Display121.5-inch display 1920 x 1080 resolution21.5-inch Retina 4K display 4096 x 2304 resolution27-inch Retina 5K display 5120 x 2880 resolution
Memory8GB8GB8GB
Storage 21TB hard drive1TB hard drive1TB hard drive or 1TB or 2TB Fusion Drive
ProcessorDual-core or quad-core Intel Core i5Quad-core Intel Core i5Quad-core Intel Core i5
GraphicsIntel HD Graphics 6000 or Intel Iris Pro Graphics 6200Intel Iris Pro Graphics 6200AMD Radeon R9 M380, M390 or M395 with 2GB GDDR5
Wireless802.11ac Wi-Fi Bluetooth 4.0802.11ac Wi-Fi Bluetooth 4.0802.11ac Wi-Fi Bluetooth 4.0
Connections and ExpansionTwo Thunderbolt 2 ports Four USB 3 ports SDXC card slotTwo Thunderbolt 2 ports Four USB 3 ports SDXC card slotTwo Thunderbolt 2 ports Four USB 3 ports SDXC card slot
CameraFaceTime HD cameraFaceTime HD cameraFaceTime HD camera
Keyboard and MouseMagic Keyboard Magic Mouse 2Magic Keyboard Magic Mouse 2Magic Keyboard Magic Mouse 2