Comment by _ph_ | Hacker News Reader

Comment by _ph_ | Hacker News Reader

Of course the whole story is way more complex, but I have been saying for years that the Itanium might have succeeded, if AMD had not extended x86 to 64 bit. The 64 bit extensions did not only fix some of the x86 problems (it increased the register count, pushed 64 bit double floats) but it made x86 a choice for the more serious compute platforms and servers.

Back then, the whole professional world had switched to 64 bit, both from a performance and memory size perspective. That is why the dotcom time basically was based on Sparc Suns. The Itanium was way late, it still was Intels only offering in the domain. Until x86-64 came and very quickly entered the professional compute centers. The performance race in the consumer space then sealed the deal by providing faster CPUs than the classic RISC processors of the time, including Itanium.

It is a bit sad to see it go, I wonder how well the architecture would have performed in modern processes. After all, an iPhone has a much larger transistor count than those "large" and "hot" Itaniums.

The industry was already moving away from the big 64 bit SMP machines made Sun, SGI & IBM. In many cases a cluster of 32bit x86 machines made more sense than one expensive big machine with high priced support contracts and parts. 32 bit x86 machines already supported more than 4GB total memory with PAE, it was just that one process couldn’t use more than 4GB. Other 64bit chips were already well established (SPARC, POWER, MIPS), probably for most of the users they couldn’t easily move to a new CPU architecture. For other users by the time they needed the bigger machines x86 64bit was already available, including from Intel themselves. AMD was limited 8 sockets from what I remember, so their was still a small market for big Itanium systems (like SGI’s Altix).

At the time there were computers containing Alpha chips with quite a PC-ish design. I nearly bought one, so they were semi-affordable. They ran Linux well. So it seems a bit more likely that these might have succeeded if AMD hadn't extended x86.

What you also have to remember is that Itanic was a very weird architecture. It's hard to write compilers for it, and it made the cardinal error of baking microarchitectural decisions into the ISA.

Yeah, by mid-2000s most RISC workstations (Alpha, Sun, SGI, PowerPC tho not IBM POWER and certainly not the top of the range datacentre class servers) had converged on the mainstream PC architecture, e.g. a PCI bus, EIDE disk controllers, standard PC memory (168-pin DIMM's and such). I had a Sun Ultra-10 as the sole «PC» at home for some years running Solaris and later Linux. After quickly getting fed up with the standard Sun keyboard, I bought a generic, no-name USB PCI card, plugged it into my Ultra-10 and connected a Microsoft Natural keyboard. It just worked, with Solaris not even requiring extra drivers or kernel modules by virtue of being a USB keyboard.

That is also my point of view, Itanium only failed because Intel's competition was allowed access to x86 design and improve upon it.

Had it not been the case and Intel alongside its OS partners would have managed to push it no matter what.

In that case, another more proven RISC architecture like Alpha would have replaced x86. At that time, the only reason why x86 was still "competitive" was the enormous amount of x86 software (specifically Windows software). If Microsoft would have to switch to another ISA anyway, there wasn't really a reason to bet on something as risky as Itanium.

For what exactly, it isn't as if Solaris was winning any desktop usage.

Microsoft and HP were already on Intel side, also Microsoft already had experience with JIT compiling x86 thanks to their collaboration for Windows NT on Alpha.

Yeah, but once Microsoft would have realized that Itanium was a performance dead end, and AMD wouldn't have jumped in as the saviour of x86, I bet Microsoft wouldn't give a shit about their good Intel relationship any longer and instead move to Alpha.

I would argue that it would have gone to PowerPC given their decision with the Xbox 360.

Alpha was one of the first architectures that they left behind.

I mean, that happened and is still happening. ARM dominates markets that didn’t exist at the time, and is constantly chipping away and x86s strongholds.

Itanium failed because of VLIW instruction set, not because of any other reason.

Without alternatives, Windows and UNIX partners would have pushed it no matter what.

If x86 compatibility would have been left behind anyway it would have opened up Windows to Intel competitors (I remember that PA-RISC was pretty hot at the time, and Alpha was also still quite revelant, although that was in the years right before the Itanium). AMD essentially saved Intel from becoming the new IBM.

HP was also moving into Itanium.

To the massive disappointment of the last Amiga die hards ;)

Maybe. Who knows. Maybe PAE could have been stretched further

Or maybe, just maybe one of those other vendors would have gotten their head out of the sand and made a 64bit processor that ran windows. But I think Wintel was set too deep to anyone challenge that

I disagree. There was ARM which would have taken over the mantle. And given the recent wins of M1 just due to abilty to decode instructions better, x86 would have died much earlier.

At that time (early 2000s) there wasn’t a high-performance ARM design. There had been StrongARM in the late 1990s, but it was sold by DEC to Intel, who killed it off. The designers moved to AMD to work on amd64.

In addition to Alpha, PowerPC was shipping in volume, reasonably competitive with a high-end option, and Windows NT had already shipped support for it along with MIPS.

The selling point for Itanium was compatibility but when they failed so badly at that it leveled out the field since you were going to have to recompile anyway.

Outside Apple and IBM, no else cared for PowerPC in any significant size for desktop users.

Windows NT originally shipped with support for all major CPUs targeted by UNIX workstations, yet all of them faded away until Itanium.

Yes, but that was largely due to Itanium’s initial optimism. My argument would be that had Intel’s x86 line also faltered, you’d have seen a lot more interest in those alternatives which had much better price/performance and also simply things like a suitable range of parts (not many people want to listen to a huge power supply on their desk). I don’t think there’s any path where people would have plunged ahead with VLIW without a radically better compiler scene.

> Windows NT originally shipped with support for all major CPUs targeted by UNIX workstations, yet all of them faded away until Itanium.

Sure, and as any Linux advocate will tell you, most folks on Windows are stuck there due to the proprietary applications that only run there. They don't care much about the OS, but they need the apps that they know and which have their data locked away.

These apps didn't run on the other processors, so Windows on other arches was mainly a curiosity.

Actually they did on Alpha, and Microsoft has just recently did the same for ARM. They would have done the same for Itanium if AMD64 had not happened.

https://en.m.wikipedia.org/wiki/FX!32

https://learn.microsoft.com/en-us/windows/arm/apps-on-arm-x8...

And price

And because Itanium's performance was worse or at least not much better than their x86 parts.

> x86-64

That came after AMD64. It was Intel trying to prevent brand damage by saying their AMD compatible cpus were not knock-offs of a competitor that had plagued them with knock-offs.

Does anyone remember when first Intel processors with AMD64 support came out Intel called it "IA32e" to downplay the importance. To differentiate it from the IA32=x86 (32bit) IA64=Itanium

I remember it as "EM64T", but Wikipedia tells me that is just the marketing name for IA32e. TIL!

Actually, it was originally called x86-64. The AMD64 branding came around about the time the chips were actually released.

Back around 2002 or 2003, I sent away to AMD for a set of reference manuals, got back a nice five-volume set which said "x86-64" everywhere and a little note in the box saying "where it says x86-64, read AMD64"

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