Didn't they also put in the NUMA stuff in Linux kernel? Also, cutting bottlenecks between CPU's and GPU's that happens today was a large part of how their early boxes achieved their performance. PC architecture just looked dumb after you saw how SGI boxes did it. Also, might consider them an early inventor of blade systems if you look at a SGI Origin with case open and a blade box. Lining up a bunch of modules in one chassis with shared power, data bus, pluggable hardware, and management system are both systems MO except SGI's had single-system image. That's if blades did come later, which I'm fuzzy on.