Apple iMac MK472LL/A 27-Inch Retina 5K Desktop (Discontinued by Manufacturer) 3.2GHz quad-core Intel Core i5 Turbo Boost up to 3.6GHz 8GB Onboard Memory (Configurable up to 32GB) 1TB Fusion Drive AMD Radeon R9 M390 graphics processor with 2GB of GDDR5 memory 27" Retina 5K Display 5120 x 2880 Resolution 3.2 GHz Intel Core i5 8GB of 1867 MHz DDR3 Onboard Memory 1TB Fusion Drive AMD Radeon R9 M390 graphics processor with 2GB of GDDR5 memory 802.11ac Wi-Fi, Bluetooth 4.0 2x Thunderbolt 2 and 4x USB 3.0 Ports FaceTime HD Camera, Dual Mics, Speakers Mac OS X El Capitan