The trouble with the CISC vs RISC interpretation is that the x86 was CISC but trashed all other architectures in the 1990s especially RISC architectures including
I think it’s as simple as a mass market architecture that sells more units can justify more investment than anything that sells fewer units. If DEC had been able to steal market share from the 386 with a VAX based product it might have been able to take the 386’s place but from a business perspective they didn’t want to cannabalize sales of higher margin minicomputers. The transition from bipolar to CMOS was also difficult because it did mean a regression in performance, IBM addressed this in the 390 by introducing a clustering solution but it was a bold and risky move.
x86 isn’t a VAX though, not all CISC architectures are equally complex (or RISC arch’s reduced), and VAX does have a reputation for being a particularly CISCy CISC. We don’t really know fully if the same tricks would have worked as well with it.
What I've read was that DEC had a huge amount of regret over the PDP-11 having too small of an address space. It could be that experience led them to think the answer to their problems was to be early to market in the 64-bit age with the Alpha. They did have VMS for the Alpha and later Win NT but high-powered RISC processors were a crowded space in the 1990s.
And, in fact, Mashey specifically discusses what you identified, and what Houle wrote (rushing to post a gotcha on HN, obviously without having read Mashey's lengthy writings).
Yeah, always good to read it. He goes into some detail about a hypothetical VAX-based x86 killer, tho some of it is "when I had beers with the guys designing the VAX..." reminiscing.
Comp.arch was something really special. Guys like Mash, John McCalpin, Bob Colwell, Eugene Maya, Mitch Alsup, Terje Mathisen...folks who really, really understood computers, what the real tradeoffs are, did actual homework instead of guessing, and were generally able to discuss the issues without being jerks. Good times.
The trouble with the CISC vs RISC interpretation is that the x86 was CISC but trashed all other architectures in the 1990s especially RISC architectures including
https://en.wikipedia.org/wiki/DEC_Alpha
and Intel’s own
https://en.wikipedia.org/wiki/Itanium
I think it’s as simple as a mass market architecture that sells more units can justify more investment than anything that sells fewer units. If DEC had been able to steal market share from the 386 with a VAX based product it might have been able to take the 386’s place but from a business perspective they didn’t want to cannabalize sales of higher margin minicomputers. The transition from bipolar to CMOS was also difficult because it did mean a regression in performance, IBM addressed this in the 390 by introducing a clustering solution but it was a bold and risky move.
x86 isn’t a VAX though, not all CISC architectures are equally complex (or RISC arch’s reduced), and VAX does have a reputation for being a particularly CISCy CISC. We don’t really know fully if the same tricks would have worked as well with it.
What I've read was that DEC had a huge amount of regret over the PDP-11 having too small of an address space. It could be that experience led them to think the answer to their problems was to be early to market in the 64-bit age with the Alpha. They did have VMS for the Alpha and later Win NT but high-powered RISC processors were a crowded space in the 1990s.
And, in fact, Mashey specifically discusses what you identified, and what Houle wrote (rushing to post a gotcha on HN, obviously without having read Mashey's lengthy writings).
Yeah, always good to read it. He goes into some detail about a hypothetical VAX-based x86 killer, tho some of it is "when I had beers with the guys designing the VAX..." reminiscing.
Comp.arch was something really special. Guys like Mash, John McCalpin, Bob Colwell, Eugene Maya, Mitch Alsup, Terje Mathisen...folks who really, really understood computers, what the real tradeoffs are, did actual homework instead of guessing, and were generally able to discuss the issues without being jerks. Good times.
Another link for some history from the DEC side is this [1].
[1] https://simh.trailing-edge.com/dsarchive.html
If you want to learn about the history of VAX chips I very strongly recommend this oral history:
Supnik, Robert oral history
https://www.computerhistory.org/collections/catalog/10273826...
If you have any interest in VAX or DEC or chip design in the 80s. This is a must watch.
Later also goes into how Alpha was created in Part 2.