This was explained here:
https://vizworld.com/2009/04/what-led-to-the-fall-of-sgi-cha...
https://vizworld.com/2009/04/what-led-to-the-fall-of-sgi-cha...
https://vizworld.com/2009/04/what-led-to-the-fall-of-sgi-cha...
https://vizworld.com/2009/04/what-led-to-the-fall-of-sgi-cha...
https://vizworld.com/2009/04/what-led-to-the-fall-of-sgi-cha...
https://vizworld.com/2009/05/what-led-to-the-fall-of-sgi-epi...