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.