Retina display 15.4-inch (diagonal) LED-backlit display with IPS technology; 2880-by-1800 native resolution at 220 pixels per inch with support for millions of colors Supported scaled resolutions: 1920 by 1200 1680 by 1050 1280 by 800 1024 by 640 300 nits brightness Standard color gamut (sRGB) 900:1 contrast ratio Processor 2.2GHz 2.2GHz quad-core Intel Core i7 processor (Turbo Boost up to 3.4GHz) with 6MB shared L3 cache Configurable to 2.5GHz quad-core Intel Core i7 (Turbo Boost up to 3.7GHz) with 6MB shared L3 cache or 2.8GHz quad-core Intel Core i7 (Turbo Boost up to 4.0GHz) with 6MB shared L3 cache. 2.5GHz 2.5GHz quad-core Intel Core i7 processor (Turbo Boost up to 3.7GHz) with 6MB shared L3 cache Configurable to 2.8GHz quad-core Intel Core i7 (Turbo Boost up to 4.0GHz) with 6MB shared L3 cache. Memory 16GB of 1600MHz DDR3L onboard memory Storage1 2.2GHz - 256GB 256GB PCIe-based flash storage Configurable to 512GB or 1TB flash storage. 2.5GHz - 512GB 512GB PCIe-based flash storage Configurable to 1TB flash storage. Size and Weight Height: 0.71 inch (1.8 cm) Width: 14.13 inches (35.89 cm) Depth: 9.73 inches (24.71 cm) Weight: 4.49 pounds (2.04 kg)2 Graphics and Video Support Intel Iris Pro Graphics​ 2.2GHz - 256GB Intel Iris Pro Graphics 2.5GHz - 512GB Intel Iris Pro Graphics AMD Radeon R9 M370X with 2GB of GDDR5 memory and automatic graphics switching Dual display and video mirroring: Simultaneously supports full native resolution on the built-in display and up to 3840 by 2160 pixels on up to two external displays, both at millions of colors Thunderbolt digital video output Native Mini DisplayPort output DVI, VGA, dual-link DVI, and HDMI output supported using Mini DisplayPort adapters (sold separately) HDMI video output Support for 1080p resolution at up to 60Hz Support for 3840-by-2160 resolution at 30Hz Support for 4096-by-2160 resolution at 24Hz Camera 720p FaceTime HD camera MagSafe 2 power port Two Thunderbolt 2...