Apple iMac 21.5-Inch Desktop - 3.1 GHz Quad-core Intel Core i7 (4th-Gen Intel Haswell CPU), 512GB Flash Storage, 16GB 1600MHz DDR3 SDRAM, NVIDIA GeForce GT 750M, Mac OS X Yosemite (NEWEST VERSION) 3.1GHz Quad-core Intel Core i7(4th-Gen Intel Haswell CPU), Turbo Boost up to 3.9GHz, NVIDIA GeForce GT 750M Graphics (1GB) 21.5-inch (diagonal) LED-backlit display with IPS technology; 1920-by-1080 resolution with support for millions of colors 16GB of 1600MHz DDR3 memory, Mac OS X Yosemite, FaceTime HD camera 512GB Flash Storage, 802.11n Wi-Fi wireless networking; 2 IEEE 802.11a/b/g compatible Simultaneously supports full native resolution on the built-in display and up to a 30-inch display (2560 by 1600 pixels) on an external display. Support for extended desktop and video mirroring modes