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What do you think are the wrong lessons that people take from IA-64? This list seems to be what you think are the "right" lessons, two of which I agree with and

What do you think are the wrong lessons that people take from IA-64? This list seems to be what you think are the "right" lessons, two of which I agree with and one I do not: A) That's still true. The best compilers for Itanium (and other VLIW architectures) are still bad and cannot make good use of the hardware. It's likely to stay that way a long time, unless programming languages and programmers adopt vector semantics ; they haven't yet. B) It's never a good time for a new ISA to succeed, except if it achieves something really novel (like GPUs for parallel processing, or ARM for power consumption). Things can succeed, but unseating an incumbent is exceptionally hard when improvement is marginal if any; Itanium, if a super smart compiler existed when it came out (they still don't ...) would have been a small improvement. It only made sense for Intel to bet on it the way they did was because they were a monopoly (or so they believed). C) I disagree; Intel didn't miss anything. They just thought they were able to dictate where the market is going. And they would have, except for AMD's guts to do AMD64. For a long time, people bought AMD64 to run 64-bit XP, so they could run with 4GB or even 8GB of RAM - even though every single process was 32-bit. But that feature was more-or-less supported also on 32-bit with bank switching and other memory extensions - the actual use of 64 bit programs (with more than 3GB per process) came much, much later.

ethbro 8y ago
The wrong lesson seems to be "Intel tried to foist something on the market that it didn't want, and AMD listened to the public." Usually by the desktop gaming crowd, who can't define VLIW or discuss the relative merits of different microarchitecture choices. On (A) and (B), I'll forgive Intel (and HP). Circa-1990, I can see it being much more debatable if making hardware (ILP) or software (VLIW) smarter were a more reliable path to performance. Especially with the market being smaller & more centralized (commercial compilers galore!). I mean, hell, AMD made the same wrong call circa-2011 in their GPU arch, no? Thus one of the reasons they ceded ML to the simpler SIMD design Nvida used which was more amenable to creating, e.g., something like CUDA? (correct me if I'm wrong) On (C), my impression was that bank switching and PAE were poorly supported by Windows at the desktop level. Which essentially made it a non-starter for the primary computer market at the time.
- beagle3 8y ago
  I don't think that lesson is wrong. I was involved with the semiconductor industry at the time, and that's how it looked from the inside (and it still does in retrospect). AMD/ATI in 2011 was still focused on graphics, ignoring the GPGPU revolution (as it was still called back then). In many ways they still haven't managed to turn around. > On (C), my impression was that bank switching and PAE were poorly supported by Windows at the desktop level. Which essentially made it a non-starter for the primary computer market at the time. I remember that while PAE was clunky, it did enable (say) running multiple processes on 8-core machines and giving each its own 2GB of memory; It was definitely poor compared to the real thing (AMD64 at the time), but like EMS, XMS and similar "extended memory" systems of the late '80s before it, it was good enough to stop people from moving to a decent architecture (e.g. Motorola 680x0) if it didn't provide backward compatibility.
  - ethbro 8y ago
    Fair. On PAE, I think the 4GB memory limit on contemporary Windows desktop OSes is what I'm remembering: https://en.wikipedia.org/wiki/Physical_Address_Extension#Microsoft_Windows https://en.wikipedia.org/wiki/Physical_Address_Extension#Mic...

ethbro 8y ago

The wrong lesson seems to be "Intel tried to foist something on the market that it didn't want, and AMD listened to the public." Usually by the desktop gaming crowd, who can't define VLIW or discuss the relative merits of different microarchitecture choices. On (A) and (B), I'll forgive Intel (and HP). Circa-1990, I can see it being much more debatable if making hardware (ILP) or software (VLIW) smarter were a more reliable path to performance. Especially with the market being smaller & more centralized (commercial compilers galore!). I mean, hell, AMD made the same wrong call circa-2011 in their GPU arch, no? Thus one of the reasons they ceded ML to the simpler SIMD design Nvida used which was more amenable to creating, e.g., something like CUDA? (correct me if I'm wrong) On (C), my impression was that bank switching and PAE were poorly supported by Windows at the desktop level. Which essentially made it a non-starter for the primary computer market at the time.

beagle3 8y ago
I don't think that lesson is wrong. I was involved with the semiconductor industry at the time, and that's how it looked from the inside (and it still does in retrospect). AMD/ATI in 2011 was still focused on graphics, ignoring the GPGPU revolution (as it was still called back then). In many ways they still haven't managed to turn around. > On (C), my impression was that bank switching and PAE were poorly supported by Windows at the desktop level. Which essentially made it a non-starter for the primary computer market at the time. I remember that while PAE was clunky, it did enable (say) running multiple processes on 8-core machines and giving each its own 2GB of memory; It was definitely poor compared to the real thing (AMD64 at the time), but like EMS, XMS and similar "extended memory" systems of the late '80s before it, it was good enough to stop people from moving to a decent architecture (e.g. Motorola 680x0) if it didn't provide backward compatibility.
- ethbro 8y ago
  Fair. On PAE, I think the 4GB memory limit on contemporary Windows desktop OSes is what I'm remembering: https://en.wikipedia.org/wiki/Physical_Address_Extension#Microsoft_Windows https://en.wikipedia.org/wiki/Physical_Address_Extension#Mic...