The main computer for the system is a dual-processor Linux PC. We chose the Linux operating system because it is compatible with much of the existing CAVE VR software tools developed for Irix. In particular, SGI's OpenGL Performer [10] toolkit is the basis for most of our current applications, and is only available for Irix and Linux. The primary drawback of Linux, compared to Microsoft Windows operating systems, is limited hardware support; in particular, fewer 3D accelerated graphics cards are supported. However, in the case of the dual-channel graphics cards that are needed for this system (discussed more in the next section), almost all consumer level cards are currently supported under Linux.
We use a computer with two CPUs because of the importance of multi-processing for reliable real-time performance; the main computer must perform application calculations and render the graphics, as well as communicating with the tracking and audio PCs.
The specific computer we are using for our prototype system has two 700 MHz Pentium III CPUs, 256 MB of 100 MHz memory, and a Matrox G450 AGP graphics card.