What parts are actually in that XPS 17 you're looking at?
The CPU, graphics card and screen resolution could be any of several options.
The i7-2630QM clocks @ 2.0GHz and Turbo boosts up to 2.9GHz, its currently set at about 2.5GHz.
The GPU is as it says a 3GB GT 555m (with optimus)
And the screen is a 17.3" FHD 1080p (1920x1080)