Eventually the 11/20 became a bit of a bear to keep running and I moved on to other machines. I passed it along to a buddy who kept it running for a few more years.
I can't say I was sad the day I replaced the SGI machines with a PC graphics card. The 3DLabs Permedia II graphics chipset was the killer. It was the first PC card with a real OpenGL driver, it was cheap, it ran under Windows NT 4.0. Game over, SGI.
The big machines machines ended up in the dumpster. I don't know if anybody dived them or not. I also had a little Indigo2 which I gave to a local guy who wanted it.