POV-Ray was my first introduction to HPC clusters. In the early aughts a few of us in college participated in a summer program at Wright Patterson Air-force Base to build a MPIPOV [1] cluster out of 10 old Sun SPARCStation 20s with "Happy Meal" NICs.
We documented the process of installing Linux (Debian), configuring the network, compiling MPIPOV from source and clustering them together.
It was a thing of beauty to watch the rendering speeds increase and the blinkenlights putting on a show in that lab when we were done.
If I remember correctly they planned to take what we documented and use for a much larger cluster they were building, but never found out the specifics.