From usenet recently, comp.arch newsgroup, a different and slightly more cynical take on Itanium, or Itanic, as it was known:-
In article <email@example.com>,
Quadibloc <firstname.lastname@example.org> wrote:
>Even if the performance problems of the Itanium architecture could be fixed, so
>as to make it something almost rivaling the Mill, Intel right now is rather too
>busy looking over its shoulder at AMD to worry about that.
Fix IA-64? There's nothing to fix.
IA-64 was a wild success that achieved it's top 2 goals before Merced
hit the market:
1) It got HP access to Intel's fabs, making PA-RISC CPUs much more
competitive for 2 years.
2) It got several mid-level managers in HP Servers promoted to outside
IA-64 started in HP Labs as PA-WideWord (called PA-WW). This was basically
the final IA-64, with the added fun benefit of fixed data cache latency
with no interlocks. (Don't laugh).
Once interlocks were added, the result was pretty much IA-64: rotating
registers, the register stack, speculation with Not-A-Thing bits, predication,
fixed bundles, etc. All the details weren't finalized, yet.
And PA-WW wasn't going anywhere inside HP.
So, midlevel managers at HP knew about PA-WW, and with evil genius
they sold this to Intel as IA64: a solution to Intel's 64-bit problem, and
as a solution for HP to have access to Intel's fab's to make PA-RISC
CPUs run faster. HP had success moving to new architectures with emulation support, so they knew they could move PA-RISC and x86 to IA-64, with a penalty of course, but it would work. And they had the detailed HP Labs data showing how fast PA-WW was going to be.
Once Intel bit, IA-64 became a train that could not be stopped inside HP.
And Intel's internal politics worked similarly: this was a way for a
down-and-out design group in Intel to show up the x86 guys.
Technically, inside HP, IA-64 was viewed as just the next thing to do:
Not much better, but not worse. And it had the "potential" to be much better.
And some folks liked the idea of working on something other people would
use (HP servers made good money, but were not popular in universities).
So there was no strong pushback. And there definitely were interesting
technical challenges that sucked folks in: VLIW, speculation, etc.
And IA-64 had the mantra "the compiler can handle this", which lots of
people suspected was not true, but which is hard to prove. IA-64 is the
proof the world needed that in-order was dead (performancewise).
And, within 3 years (and before Merced shipped), all the mid-level HP managers
involved had been promoted to positions outside HP. It's a skill to
get out before your chickens come home to roost. And PA-RISC CPUs
hit new MHz targets, doubling in speed in 2 years, on Intel fabs.
So IA-64 was clearly successful.
Oh, you mean as a computer to actually buy? Oh, that's different.
And PA-RISC CPUs got even faster on an IBM SOI fab, doubling in speed in
another 2 years, making access to the Intel fabs unnecessary.
IA-64 was foisted onto the world so some managers could be
big-wigs for a while and get promotions.