> It’s equally plausible to me that Intel would have continued to see strong x86 sales and weak demand for Itanium and ended up shipping their own 64-bit extens

> It’s equally plausible to me that Intel would have continued to see strong x86 sales and weak demand for Itanium and ended up shipping their own 64-bit extension a few years later with less pressure from AMD simply because businesses weren’t keen on the “recompile everything, make a bunch of expensive optimizations, and it might be faster than the system it’s replacing” I agree it is plausible, but the "few" in "few years later" makes a huge difference. Itanium was not requested or driven by the market, not even wanted; it was dictated by Intel, who put in billions into it. Without any market pressure, they would have likely taken their sweet time - possibly 10 or more years - to let Itanium mature. They actually took the writeoff for Itanium as late as they could - I would guess no one wants to one such a colossal failure, and that would have been true even if AMD wasn't around. While IA-64 originated in HP, as another poster noted, it was in Intel's interest that HP would be out of the CPU market, and in that sense Itanium was a success -- it left Intel in a much stronger position in the long run, and if it wasn't for you meddling AMD kids, they would have gotten away with it in the short run as well.