What's the desktop video card equivalent of ATI mobility radeon 5870?

Im planning to purchase the new asus g73jh that has the ATI mobility radeon 5870, but what's the desktop equivalent of that video card? Since I might also consider building my own PC gaming rig instead. Thanks and have a nice day.|||From what I see it's basically a Radeon HD 5770 with a slower clock speed (700Mhz as opposed to 850Mhz).|||ATi Radeon HD5870.