Indigo2 is just convergent evolution. The Indigo2 family had EISA slots, so it was obliged to hold a full-length ISA card. There are only so many ways to skin

Indigo2 is just convergent evolution. The Indigo2 family had EISA slots, so it was obliged to hold a full-length ISA card. There are only so many ways to skin that cat: You want a small, thin desktop with quiet cooling that will also fit a full length ISA card. LPX and Indigo2 look similar because they were solving the same problem. See also: Octane and Origin 200 vis a vis ATX and WATX. When SGI adopted 64 bit PCI, their desktop-sized systems started to look a bit like ATX, despite a radically different underlying architecture ----------- The equivalent Sun and HP9000 kit could look quite different because they did not even try to offer EISA as an option Later Sun and HP9000 kit, with PCI64 slots, started to converge on an ATX "look" for similar reasons to the I2 and LPX