PowerPC is the one I’d have bet on - Apple provided baseline volume, IBM’s fabs were competitive enough to be viable, and Windows NT had support. If you had the same Itanium stumble without the unexpectedly-strong x86 options, it’s not hard to imagine that having gotten traction. One other what-if game is asking what would’ve happened if Rick Belluzzo had either not been swayed by the Itanium/Windows pitch or been less effective advocating for it: he took PA-RISC and MIPS out, and really helped boost the idea that the combination was inevitable.
I also wouldn’t have ruled out Alpha. That’s another what-if scenario but they had 2-3 times Intel’s top performance and a clean 64-bit system a decade earlier. The main barrier was the staggering managerial incompetence at DEC: it was almost impossible to buy one unless you were a large existing customer. If they’d had a single competent executive, they could have been far more competitive.
Interesting to note that all state of the art video game consoles of the era (xbox 360, PS3 and Wii) used PowerPC CPUs (in the preceding generation the xbox used a Pentium III, the PS2 used MIPS and the GameCube was already PPC).
I also wouldn’t have ruled out Alpha. That’s another what-if scenario but they had 2-3 times Intel’s top performance and a clean 64-bit system a decade earlier. The main barrier was the staggering managerial incompetence at DEC: it was almost impossible to buy one unless you were a large existing customer. If they’d had a single competent executive, they could have been far more competitive.