The M4700 and M6700 pack Intel's latest third-generation Core i5 and i7 processors and come with a range of customisable hardware features.
Both machines launch with Microsoft's Windows 7, with Red Hat Enterprise Linux 6 available as an alternative in selected territories.
Dell describes the Precision M6700 as the industry's "lightest 17-inch mobile workstation", weighing in at 3.52kg. A special 'Covert' edition of the computer with an optional 3D screen and Nvidia glasses will also be available with a higher price tag.
Weighing in at around 2.78kg, the M4700 features a smaller 15.6-inch screen and runs off a six-cell battery, offering less run time than the high-end model's nine-cell.
Both models include optional Nvidia Quadro or Advanced Micro Devices' FirePro graphics card support, and are capable of displaying imagery at the high-definition 1920 by 1080-pixel resolution.
They also combine a 512GB solid-state drive, a 256GB SSD and a 750GB hard drive, as well as hosting USB 3.0 ports and USB 2.0/eSATA ports.
The 15-inch M4700 is available for £999 in the UK, while the 17-inch M6700 starts at £1,349.