If you don't have 1 GB of hard drive space for Descent 3, you'll need a CD-ROM to play the movies (and to access data files on a bare minimum install).
The Vaio Digital Studio 547 computer includes a 500MHz Pentium III processor, 128 MB of RAM, a 8x DVD-ROM drive, a 4x Rewritable CD (CD-RW) drive, and a 20 GB hard drive.