Perhaps all the purple rack onyx had been dumped but we dug through ILMs boneyard looking to add to our cxfs cluster, but the FC bus speed was too low.
It is possible that R10k was different or that there were multiple chassis. The desk sides I had experience with required RAM in slot 1, with CPU in slot 2, with up to 4 CPUs on the board.
o200 was more restrictive, with 2 CPUs per chassis, with the ability to cray-link two chassis for a total of 4 CPUs, more required o2000.
But this was a quarter of a century ago or more by now…so I may misremember things.