HPE SuperDome
Having spent many years supporting systems utilising several generations of Itanium on HPE SuperDome 2 running HP-UX, I have to defend it a bit.
We were able to successfully host multiple environments (database count into the hundred's) on each vPAR partition with minimal cores. The system performed well and was extremely stable.
However.... we saw the writing on the wall, and re-platformed the applications onto X86-64 and Linux a few years ago. RIP Itanium