Fourth-generation Intel Core processors in Mac Book Air give you more time to do more things. Add that to an array of other smart & efficient features, & you have an incredible amount of power in your hands. While carrying next to nothing. ** Up to 12 hours of battery life. Power through your whole day.** Thanks to compact all-flash storage in Mac Book Air, there's plenty of room for a big battery. Working together with the new power-efficient Intel Core architecture, this battery can post some impressive numbers. Now the 13-inch model gets up to 12 hours of battery life on a single charge & the 11-inch model gets up to 9 hours. That gives you all-day power for word processing, presentations, email & more. & if you're watching i Tunes films, you get up to 10 hours of playback time on the 13-inch model & up to 8 hours on the 11-inch. Put Mac Book Air to sleep for more than 3 hours, & it enters standby mode to conserve battery life for up to 30 days. & if you enable Power Nap, you'll continue to receive new email & calendar invitations while your computer is asleep. ** Fourth-generation Intel Core processors. Performance, meet endurance.** Mac Book Air is powered by the all-new fourth-generation Intel Core i 5 & i 7 processors. This ultra-efficient architecture was designed to use less power & still deliver high performance. Which means not only can you do whatever you want -- you can keep doing it for longer than before. In addition, the new Intel HD Graphics 5000 offers up to 40 per cent faster graphics -- performance you'll especially notice with games & other graphics-intensive tasks. ** Up to 3x faster Wi-Fi. 802.11ac. The new definition of fast.** Mac Book Air now supports ultra-fast 802.11ac Wi-Fi. When connected to an 802.11ac base station -- including the new Air Port Extreme & Air Port Time Capsule -- wireless performance is up to 3x faster than with the previous generation of Mac Book Air. & your Wi-Fi range improves as well.