Intel Core i5 - i7 Turbo Boost up to 3.9 GHz

3.2GHz/ 3.3GHz AMD Radeon R9 M380/ M390/ M395 Configurable to AMD Radeon R9 M395X with 4GB of GDDR5 memory

8GB (two 4GB) of 1867MHz DDR3 memory; four SO-DIMM slots, user accessible Configurable to 16GB or 32GB

3.2GHz [1TB (7200-rpm) hard drive Configurable up to 3TB Fusion Drive or 256GB or 512GB of flash storage (SSD)]; 3.2GHz [1TB Fusion Drive Configurable up to 3TB Fusion Drive or 256GB, 512GB, or 1TB of flash storage (SSD)]; 3.3GHz [2TB Fusion Drive Configurable up to 3TB Fusion Drive or 256GB, 512GB, or 1TB of flash storage (SSD)]

27-inch (diagonal) Retina 5K display with IPS technology; 5120‑by‑2880 resolution with support for millions of colors

FaceTime HD camera

Height: 20.3 inches (51.6 cm), Width: 25.6 inches (65.0 cm), Stand depth: 8 inches (20.3 cm), Weight: 21 pounds (9.54 kg)2, *Depth (including built-in VESA adapter): 3.1 inches (7.9 cm)

Simultaneously supports full native resolution on the built-in display and up to two 4096-by-2160 external displays or one 5120-by-2880 dual-cable external display, Support for extended desktop and video mirroring modes

802.11ac Wi-Fi wireless networking IEEE 802.11a/b/g/n compatible

Bluetooth 4.0 wireless technology

3.5 mm headphone jack SDXC card slot Four USB 3 ports (compatible with USB 2) Two Thunderbolt 2 ports Mini DisplayPort output Support for HDMI, DVI, VGA, and dual-link DVI (adapters sold separately)

10/100/1000BASE-T Gigabit Ethernet (RJ-45 connector) Kensington lock slot

Magic Keyboard, Magic Mouse, Magic Trackpad

Sierra

Silver