The Apple MacBook Air "Core i5" 1.7 13" (Mid-2011/Thunderbolt) features a 32-nm "Sandy Bridge" 1.7 GHz Intel "Core i5" processor (2557M) with two independent processor "cores" on a single chip, a 3 MB shared level 3 cache, 4 GB of onboard 1333 MHz DDR3 SDRAM (which cannot be upgraded after purchase), 256 GB of flash storage, and an Intel HD Graphics 3000 graphics processor with 384 MB of DDR3 SDRAM shared with system memory. This all is packed in a razor-thin (0.11-0.68 inch), 2.96 pound, aluminum case with an integrated "FaceTime" video camera, a backlit full-size keyboard and an 13.3" widescreen TFT LED backlit active-matrix "glossy" display (1440x900 native resolution). Connectivity includes 802.11a/b/g/n Wi-Fi, Bluetooth 4.0, dual USB 2.0 ports and analog audio out as well as an SDXC card slot and a new "Thunderbolt" port that is backward compatible with Mini DisplayPort and likewise supports an external display at 2560x1600 and passes an audio signal as well. Thunderbolt also supports other peripherals that use the Thunderbolt standard which provides up to 10 Gbps of bandwidth in both directions. It lacks internal Ethernet (an external USB adapter was offered as a US$29 option) and lacks Firewire and optical audio in/out as well.