>Anything you can run on Itanium is almost certainly going to work better on AMD64.
I worked on a project targeting hp superdomes (PA RISC). When that architecture was on its way out they started looking at amd64 as a replacement though Itaniun was the “successor” to hp risc and could run hpux (HP was involved somehow). It really never took off. The advance compilers that would give itanium software speed never really happened.