Apple updated its best-selling computer line with new 11.6-inch and 13.3-inch MacBook Pro models packing Intel's fourth-generation Core Haswell chips.

The MacBook Pro is very popular due to its slim and light profile, as well as its powerful features, but now the Cupertino tech giant significantly bumped up the power with the new Intel Haswell CPUs.

The Intel Haswell line of Core i5 and Core i7 CPUs will deliver considerably superior battery performance that lasts up to nine hours for the 11.6-inch MacBook Air and up to 12 hours for the bigger 13.3-inch model. The previous generation models lasted for five and seven hours, respectively.

"The 11-inch MacBook Air now lasts up to 9 hours between charges and the 13-inch model lasts up to an incredible 12 hours," Apple proudly touts. "So from your morning coffee till your evening commute, you can work unplugged. When it's time to kick back and relax, you can get up to 10 hours of iTunes movie playback on the 13-inch model and up to 8 hours on the 11-inch model. And with up to 30 days of standby time, you can go away for weeks and pick up right where you left off."

Intel HD graphics accompany the Haswell Core i5 and Core i7 CPUs and promises up to 40 percent faster graphics. The new MacBook Air models will also sport the new 802.11ac Wi-Fi (the fifth-generation wireless standard) and both models will now embrace SSD as the standard storage option, available in 128GB and 256GB configurations.

The base price for the new MacBook Air remains $999, which means it's the cheapest MacBook around, but this time interested buyers will get more for that sum: 128GB of SSD storage instead of last year's meager 64GB. The higher-end model, meanwhile, goes up to $1,199 but doubles the storage to 256GB. Moreover, upgrading to 512GB now costs less than it did last year: the 11-inch MacBook Air in a 512GB configuration now costs $1,499. It may not be cheap, but it's definitely more reasonable than last year. The Retina display, however, is still not on board.

Apple unveiled its new MacBook Air models at its Worldwide Developers Conference (WWDC) 2013 and both models are already available for purchase from Apple's store, with shipping slated to start in a few days.