Athlon 64: How AMD turned the tables on Intel

I remember at the time thinking it was really silly for Intel to release a 64-bit processor that broke compatibility, and was very glad AMD kept it. Years later I learned about kernel writing, and I now get why Intel tried to break with the old - the compatibility hacks piled up on x86 are truly awful. But ultimately, customers don't care about that, they just want their stuff to run.

Intel might have been successful with the transition if they didn't decide to go with such radically different and real-world untested architecture for Itanium.

Well that and Itanium was eyewateringly expensive and standard PC was much cheaper for similar or faster speeds.

I think Itanium was a remarkable success in some other ways. Intel utterly destroyed the workstation market with it. HP-UX, IRIX, AIX, Solaris.

Itanium sounded the deathknell for all of them.

The only Unix to survive with any market share is MacOS, (arguably because of its lateness to the party) and it has only relatively recently went back to a more bespoke architecture

Absolutely not. Sun destroyed itself and Solaris, not Intel. The others were even more also-rans than Solaris.