MacBook Air 2013 - 13"

Compared to its predecessor, this model has effectively the same external enclosure, but it has a much more efficient processor and architecture -- which results in significantly improved battery life -- as well as faster graphics (that reserve more system memory), faster storage, and faster Wi-Fi.
The Apple MacBook Air "Core i7" 1.7 13-Inch features a 22-nm "Haswell" 1.7 GHz Intel "Core i7" processor (4650U) with two independent processor "cores" on a single chip, a 4 MB shared level 3 cache, 4 GB of onboard 1600 MHz LPDDR3 SDRAM-8 GB, 256 GB of PCIe-based flash storage, and an "integrated" Intel HD Graphics 5000 graphics processor that shares system memory.
This all is packed in a razor thin (0.11-0.68 inch), 2.96 pound, aluminum case with an integrated 720p "FaceTime HD" webcam, a backlit full-size keyboard and an 13.3" widescreen TFT LED backlit active-matrix "glossy" display (1440x900 native resolution).