Apple Inc., known for being a trendsetter, has continued along those lines with its new lighter and thinner MacBook Air -- which is less than a month old. But the U.S. company is facing competition in the ultrathin notebook category from Taiwan-based Asus, which is getting ready to release a slightly thinner device called the Asus UX21.

Both companies are pushing the boundaries of technology.

Since Apple released the first MacBook Air in 2008, the device has come to define what it means to be avant-garde in its category, and the latest MacBook Air is no exception -- sporting a sleek thin aluminum frame, a full-sized keyboard and screen and no moving parts.

Not to be outdone though, Asus announced earlier this year at the Computex computer expo that the company is preparing to unveil its own new UX series ultra-portable notebook, which will go on sale in September.

Quick Look at Specifications:

11-inch Asus UX21

Dimensions: 3 milimeters at its thinnest, 17 milimeters at its thickest; weighs 2.4 pounds, aluminum

Display: 11.6-inch, 1366x768 resolution

Processor: Intel Core i5-2557M 1.7GHz with option for upgrade to Core i7

RAM: 2 GB

Storage: 64 GB or 128 GB SSD SATA-III

Connector: USB 3.0 technology, two USB ports, Mini HDMI ports

Battery: 6-cell battery, lasts up to seven hours

OS: Windows 7

Price: Under $1,000

11-inch MacBook Air

Dimensions: 0.68 inches (17.27 milimeters) thick, 2.4 pounds, aluminum

Display: 11.6-inch, 1366x768 resolution

Processor: 1.6 GHz dual-core Intel Core i5 to 1.8 GHz dual-core Intel Core i7

RAM: 2 GB/4 GB

Storage: 64 GB or 128 GB Flash Storage, upgradable to 256 GB

Connector: two USB 2.0 ports, Thunderbolt, headphone port, MagSafe power port

Battery: Internal battery rated at five hours

OS: OS X Lion 10.7

Price: $999/$1,199

Mobility

The first MacBook Air boasted of being the "world's thinnest" laptop at the time of introduction. But it will be overtaken by the Asus UX21 when it gets released, which is just 0.66 inches thick at the maximum, less than the new MacBook Air's 0.68-inch thickness. 

Add to that, the Asus UX21 comes in a svelte aluminum alloy shell that has a "spun" finish on the polished surface. Asus is noted for its exquisite design, and nowhere else is this more evident than in the new UX Series, developed in close cooperation with Intel.

The artistry of the UX series draws inspiration from luxury timepieces, displaying sharp edges, an oversized keyboard and smartphone-like touchpad for added comfort, as well as reinforced hinges for extended longevity.

Asus UX21 overtakes the MacBook Air with its battery life. For a typical consumer though, there isn't much difference here. Up to  seven hour battery charges mean that the Asus UX21 is always ready for action -- and with the Instant On feature it resumes work in seconds.

But Flash gives MacBook Air the astonishing ability to remain in standby mode for up to 30 days. For the Asus UX21, the standby time is still unknown.

Performance

Both the MacBook Air and the Asus UX21 are built on top of Intel's Sandy Bridge architecture, giving them both the latest processor technology, among other things. But they differ in one very important detail.

The Macbook Air uses a low-voltage version of Intel's Core i5 processor that could be upgradeable to Intel Core i7. This is typical for ultra-portable notebooks, and is par for the course. But Asus was able to squeeze a full-powered i5 or i7 processor into UX21's diminutive body.

But when it comes to RAM space, the MacBook Air has a 2GB version, which is configurable to 4GB at the Apple Online Store. It also has a 4GB version.

In addition, the new MacBook Air comes with Apple's new OS X Lion, which has been declared by the company as the "the world's most advanced desktop operating system," touting the addition of more than 250 new features. On the other hand, Asus UX21 has Microsoft's Windows 7 operating system.

The new MacBook Air is priced at $999 for the 2GB model and $1,199 for 4GB model with 1333MHz DDR3 onboard memory. On the other hand, the Asus UX21 is expected to be priced under $1,000.

Conclusion

With each having its own allure, beauty is in the eye of the beholder. Typical consumers can get enough done on the road with either, but for the more demanding, performance-based mobile professional, the Asus UX21 wins. When it comes to RAM space, MacBook Air wins. And in terms of pricing, both devices are at the same level.