See also https://support.apple.com/kb/sp700
Display
The 13-inch Air looks the same as the last few models, sporting a svelte and elegant unibody aluminum chassis with rounded corners. The machine also feels sturdy. We've used another 13-inch Air for a few years in a row without so much as a dent or worn-down key. Apple's logo glows on the smooth lid, which doesn't pick up fingerprints.
Heat
The MacBook Air is one of the coolest-running ultraportables we've tested. After streaming a Hulu video at full screen for 15 minutes, the touchpad registered just 75 degrees. That's 20 degrees below our comfort threshold. The area between the G and H keys hit 80 degrees, while the bottom reached 81 degrees.
Performance
Apple now equips the MacBook Air with a 1.5-GHz Core i5 processor, up from 1.3 GHz on the previous model, along with 4GB of RAM and 128GB of PCIe-based flash storage. The result is a system that's fast and responsive -- whether you're editing photos in Pixelmator or opening multiple files at once -- but not superior to its predecessor in all ways.