Operating altitude: tested up to 10,000 feet.Relative humidity: 0% to 90% noncondensing.Operating temperature: 50° to 95° F (10° to 35° C).60W MagSafe Power Adapter with cable management system MagSafe power port.Built-in 63.5-watt-hour lithium-polymer battery.Multi-Touch trackpad for precise cursor control supports inertial scrolling, pinch, rotate, swipe, three-finger swipe, four-finger swipe, tap, double-tap, and drag capabilities.Full-size backlit keyboard with 78 (U.S.) or 79 (ISO) keys, including 12 function keys and 4 arrow keys (inverted “T” arrangement) with ambient light sensor.Support for audio line out (digital/analog).Support for Apple iPhone headset with remote and microphone.802.11n Wi-Fi wireless networking 3 IEEE 802.11a/b/g compatible.HDMI audio and video output using third-party Mini DisplayPort to HDMI Adapter (sold separately).Dual-link DVI output using Mini DisplayPort to Dual-Link DVI Adapter (sold separately).VGA output using Mini DisplayPort to VGA Adapter (sold separately).DVI output using Mini DisplayPort to DVI Adapter (sold separately).Dual display and video mirroring: Simultaneously supports full native resolution on the built-in display and up to 2560 by 1600 pixels on an external display, both at millions of colors.2.9GHz dual-core Intel Core i7 processor (Turbo Boost up to 3.6GHz) with 4MB 元 cache.

2.5GHz dual-core Intel Core i5 processor (Turbo Boost up to 3.1GHz) with 3MB 元 cache.13.3-inch (diagonal) LED-backlit glossy widescreen display with support for millions of colors.

Retina macbook pro 13in 8gb vs 16gb ram