[zozbot123]

> I do not want a monopoly in x86.

Strictly speaking, x86-64 patents must be about to expire anyway - the first Intel EM64T implementation (which can be assumed to be fully compatible even with modern-day software--IIRC the original AMD64 ISA had some unfortunate quirks which make this less likely) is from 2004. So, it's only a matter of time until we see compatible x86-64 CPUs from other vendors.

[okl]

There are tons of patents regarding implementation details and instruction set extensions. I don't think you could sell Athlon 64 or Pentium D clones to anyone.

[zozbot123]

Not sure about the original Athlon 64, but Pentium D's can apparently run, e.g. Win10 for x86-64 and its associated software (barring ISA extensions, of course) - surely that's good enough for some users. Especially if you could reimplement the "clone" on a more recent physical node than an actual Pentium D.