Intel Itanium IA-64 Support To Be Deprecated By GCC 10, Planned Removal In GCC 11

[L_A_G]

...

I think the later failure of the architecture has colored your perception pretty badly. In case your memory fails you or you never heard of this, Silicon Graphics and Compaq/DEC abandoned MIPS and Alpha respectively specifically to focus on making Itanium-based systems instead. Both IBM and Dell made servers using the chips completely out of their own will as shown by how HP couldn't sue them for breaking any contractual obligations like they did when Oracle decided it was time to abandon ship. IBM and Dell's exit from the Itanium server market didn't even happen until 2005, 4 years after the first Itanium chips came out and 2 years after the second series came out.

AFAIK Itanium server sales topped out at about two billion a year and the real phase-out of properly invested parties didn't really start until around 2010 when Intel dropped IA64 support from their then latest version of ICC and Microsoft announced their phase-out for the architecture.

As for AMD64, now more commonly known as x86_64 after Microsoft told Intel in no uncertain terms that they weren't going to support their alternative 64 bit x86 architecture, I highly doubt it was an act of desperation. All CPU makers outside of ones dedicated to embedded systems knew by the mid 90s that a move to 64 bit was inevitable and needed to get underway as soon as possible so AMD was obviously just doing what everyone knew when it started work on what would be known as AMD64.

[bison]

A few good ideas? I can't even think of one.

In-order execution, which is not susceptible to side channel attacks.

[jacob]

The whole story of IA64 is a kinda sad mess when you find out about what it was supposed to be and how things actually ended up going.

Intel originally intended it to replace 32 bit x86 and have AMD waste their time creating their own 64 bit x86, which they gave the rather unimaginative name "AMD64". The Itanimum hardware was supposed to offer much better performance while offering full backwards compatibility, but the hardware that actually came out wasn't much faster than the competition and ran 32 bit x86 code pretty slow due to having separate dedicated hardware for doing so. Some estimates said that the performance was about on par with a 100 MHz Pentium 1 when the original Pentium 4s were already on the market. To add insult to injury AMD soon released the original Opteron which not only traded blows with the Itanium on native code, but also ran 32 bit x86 applications much faster thanks to not needing separate dedicated hardware to do so.

It obviously didn't take long for Itanium to pick up the nickname "Itanic" as it failed to get support from end users and as a result hardware vendors like Dell and IBM along with software vendors like Microsoft and Oracle started dropping support. Silicon Graphics, then going by the abbreviation SGI, even went belly-up partially because of their failed bet on Itanium systems. Eventually it got to the point where HP, who co-developed the architecture together with Intel, started suing software vendors like Oracle and Microsoft to keep them from dropping support. Worse yet, with those court records it came out that HP was literally paying for software vendors to support Itanium and in the case of Oracle this amount was 690 million dollars annually.

Obviously Itanic never reached the lofty heights it was intended for either in terms of sales or performance. The only reason why it stayed around for this long was because of HP's continued investment and how credibly hard it's marketing department pushed their Itanic-based systems up until at least last year. Because of this I'm pretty sure that many companies who fell for the HP sales pitch won't be buying any HP products for a long time to come.

I don't remember all the details but it was actually pretty simple. The WLIW/EPIC concept originated at HP. Someone must have smoked something particularly heavy and thought that it would ever be a good idea, but HP needed a parter to implement it. Then there was Intel with two problems. On one hand, they really, really wanted to get AMD out of the market, but that required changing the instruction set, because they couldn't stop AMD from making x86-compatible CPUs (they tried, and failed). That was one of the primary motivation for Intel's many failed attempts at launching a new architecture (iAPX432, i860, i960 etc.) On the other hand, the Apple-IBM-Motorola alliance released its PowerPC processors which, Intel feared, could offer a better price/performance ratio than its then-flagship, the Pentium (and for some time, they indeed did). The result of all this was the Intel-HP alliance where Intel would implement and manufacture HP's design.

The thing is, nobody outside of HP (not even sure about Intel) seriously thought this would ever work. IIRC the nickname Itanic appeared on the NEXT DAY after Intel announced the Itanium brand. Then the first core (Merced) was released, extremely expensive, with lacklustre performance on native code and a x86-compatible mode that ran at the speed of a 100MHz Pentium and virtually everyone made their mind at that stage.

Meanwhile AMD feared that if the Itanic caught up, it would indeed lose its market. They created AMD64 as a desperate attempt to stay relevant by offering the first affordable 64-bit CPU for the masses. So Intel had its Itanic and AMD had a design that offered excellent performance at a fraction of Intel's cost and, at the same time, had basically no downsides as in the absolutely worst case, it would just run 32-bit software like any ordinary x86 processor with no penalty. The rest, as they say, is history.

[jacob]

OMG.. WTF? I never even heard of it, and it is absolutely gloriously insane:

Instruction length: 6 to 321 bits.. yes, bit aligned
Object oriented instructions... Yes really
Hardware defined and enforced software data types....
Hardware garbage collection........

The Atari Jaguar was another beauty. The purportedly "64 bit" architecture had in fact a M68000 combined with two proprietary 32 bit cores which were kinda-sorta-but-not-really compatible with each other. It wasn't a SMP architecture but rather a weird brand of master/slave architecture in which any of the cores could be used as master. Now of course some parts were big endian and some little endian, which was especially "fun" to code for. As an extra garnish, in the great Atari tradition there was zero documentation, no compiler to speak of, no development environment and when the Atari technical support team was asked questions at developer conferences, their honest answer typically was that they had no idea.

[L_A_G]

The whole story of IA64 is a kinda sad mess when you find out about what it was supposed to be and how things actually ended up going.

Intel originally intended it to replace 32 bit x86 and have AMD waste their time creating their own 64 bit x86, which they gave the rather unimaginative name "AMD64". The Itanimum hardware was supposed to offer much better performance while offering full backwards compatibility, but the hardware that actually came out wasn't much faster than the competition and ran 32 bit x86 code pretty slow due to having separate dedicated hardware for doing so. Some estimates said that the performance was about on par with a 100 MHz Pentium 1 when the original Pentium 4s were already on the market. To add insult to injury AMD soon released the original Opteron which not only traded blows with the Itanium on native code, but also ran 32 bit x86 applications much faster thanks to not needing separate dedicated hardware to do so.

It obviously didn't take long for Itanium to pick up the nickname "Itanic" as it failed to get support from end users and as a result hardware vendors like Dell and IBM along with software vendors like Microsoft and Oracle started dropping support. Silicon Graphics, then going by the abbreviation SGI, even went belly-up partially because of their failed bet on Itanium systems. Eventually it got to the point where HP, who co-developed the architecture together with Intel, started suing software vendors like Oracle and Microsoft to keep them from dropping support. Worse yet, with those court records it came out that HP was literally paying for software vendors to support Itanium and in the case of Oracle this amount was 690 million dollars annually.

Obviously Itanic never reached the lofty heights it was intended for either in terms of sales or performance. The only reason why it stayed around for this long was because of HP's continued investment and how credibly hard it's marketing department pushed their Itanic-based systems up until at least last year. Because of this I'm pretty sure that many companies who fell for the HP sales pitch won't be buying any HP products for a long time to come.

[jacob]

ONE of the worst? It was several of the worst ideas put together, with a few good ideas thrown in as garnish.

A few good ideas? I can't even think of one. Except maybe some stuff like SMT, which other CPUs have too and which is basically contrary to the very concept of the Itanium. They implemented it as a band-aid trying to make up for a fundamentally terrible design.

[carewolf]

Lest we forget iAPX 432… 😏

OMG.. WTF? I never even heard of it, and it is absolutely gloriously insane:

Instruction length: 6 to 321 bits.. yes, bit aligned
Object oriented instructions... Yes really
Hardware defined and enforced software data types....
Hardware garbage collection........

[carewolf]

The Itanic will be remembered as one of the worst ideas in CPU design history, with a botched implementation to match.

ONE of the worst? It was several of the worst ideas put together, with a few good ideas thrown in as garnish.

[jacob]

I guess we could say iAPX 432 was too CISCy, while IA-64 was too RISCy. History shows that the sweet spot lies somewhere between the two philosophies.

I think if you want high performance, the sweet spot is a CISC instruction set dynamically translated and executed on an internal RISC core. That's what modern CPUs do. For low cost/low power consumption, RISC is great. The iAPX432 was extremely complex and at the same time, it always looked like a solution in search of a problem.

[Veto]

Lest we forget iAPX 432… 😏

Yeah, intel really does not have a "stellar" history of introducing new CPU architectures or product lines. I know a lot of users where burned, when they abandoned the i960 and the StrongARM/XScale basically overnight in both cases. At this point I will personally only trust intel to keep making i86 CPUs...