Specs Alienware x51 R2 i5-4440 Desktop Intel® Core™ i5 16 GB DDR3-SDRAM 1000 GB HDD Windows 7 Home Premium Mini PC Black PCs/Workstations (ALWX51D-2628)
X51 R2 documentation. NZXT H510 Case and standard power supply. - Dell Community
Alienware X51 R2 user manual (English - 18 pages)
Dell Alienware X51 specifications
User manual Alienware Area 51-R2 (English - 133 pages)