You’re right - I was being inexact re AMD. Itanium is an interesting historical example. I think Intel learnt the wrong lesson though: ‘cling to x86 at all cos

You’re right - I was being inexact re AMD. Itanium is an interesting historical example. I think Intel learnt the wrong lesson though: ‘cling to x86 at all costs’ when it was really that Itanium was just the wrong product. If they’d pushed a high quality Intel only 64 bit RISC design instead of Itanium at the time they might have succeeded. Edit: Just to expand on this a bit. At the time of Itanium they had a clear process lead. They could have offered the best server CPUs on an Intel only RISC ISA and invested heavily in helping customers migrate. Arm got customers from aarch32 to aarch64 seamlessly.