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IBM Businesses Apple Hardware

POWER Processors, SMT and the True Origins of AI 34

Crow writes "IBM developerWorks has posted an interview with John McCalpin, one of the guys who works on the POWER line of processors. He discusses work on POWER5 (and how the design process works at IBM -- he's also involved in work on the POWER7) and defends the decision that IBM doesn't hand-tune their ICs (as has often been criticized on Ars Technica. Also covers some of the features in the POWER processors, like SMT, the Hypervisor and virtualization -- even addresses the question of whether AIX was designed by space aliens or not. The POWER5 just broke the 3 million transactions per minute barrier on the TPC-C benchmark."
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POWER Processors, SMT and the True Origins of AI

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  • AI (Score:3, Insightful)

    by jbloggs ( 535329 ) * on Tuesday November 23, 2004 @05:06PM (#10903646)
    Where's the bit on the true origins of AI?
  • by infinite_improbabili ( 833732 ) on Tuesday November 23, 2004 @05:31PM (#10903926)
    dW: That is a shame. I have one more on the subject of OSes -- was AIX really designed by space aliens?
    McCalpin: I hadn't heard that one. It feels like it was designed by, [not space aliens, but] in some part by people with mainframe backgrounds..."

    Apparently the aliens have embedded mind control in AIX!
  • Comp Eng at IBM (Score:4, Insightful)

    by KingOfTheNerds ( 706852 ) on Tuesday November 23, 2004 @07:18PM (#10904977) Homepage
    I worked recently as a contractor for IBM where I helped contribute to the design decisions for the POWER7. This article is great because it describes how the design decisions happen at IBM and it is right on the money. It's interesting because the way IBM does it is different from most other companies.
    • Could you elaborate on the differences?

      I see:
      "We spend a gread deal of time in meetings"
      and
      "So, the issues as far as the design of the system are argued out in many meetings by the technical leadership, some of whom are first and second line managers and some of whom are STSM's and DE's [Distinguished Engineers --eds.] and Fellows. We eventually come to a level of consensus about which of the items that have been proposed are fundable and the remainder are not. "

      How is that different from the other compan
  • by CaptKilljoy ( 687808 ) on Tuesday November 23, 2004 @09:31PM (#10906042)
    A good quote to break out when people claim that cluster supercomputers are "better" than vector supercomputers (when they're really two different types of systems with differing strengths that can't be directly compared):

    >McCalpin: The majority of high-end systems are used for throughput workloads of one kind or another. The vector machines, both from NEC and Cray(TM), are very well-liked by the end users because vectorization is a relatively easy thing to understand, how to write code that will vectorize. And the machines -- with relatively little effort -- give you a good utilization, you'll get a good fraction of the peak theoretical performance without a whole lot of work. And customers find that comforting. You put the code on there, you get 35% of the theoretical peak performance and you say, "Well, that's pretty good and I don't need to mess with it anymore."

    On the machines that IBM sells and that HP sells and AMD(TM) and all of the others, the costs are much lower, but it's harder to get very high utilization on those machines, in part because they don't have so much expensive memory bandwidth. So there's an interesting discrepancy between the end users who love vector machines because they're easy to use and then the purchasing manager who doesn't like vector machines because they cost too much.
  • by user9918277462 ( 834092 ) on Tuesday November 23, 2004 @11:57PM (#10906851) Journal
    The IBM POWER line (including PPC) is the one and only true threat to Intel's dominance of the hardware market. Remember that AMD pays royalties to Intel for every chip it sells, which pretty much condemns them to permanent second-place competitor.

    Once the PPC 970 (or some successor) starts shipping in commodity beige boxes, however, the entire marketplace will be turned upside down. Can you imagine buying the generic equivalent of a dual proc G5 for $600? Sweet.
    • Um, ya. Go read some newsgroup posts from around '90 on the google groups archives. Apperently we were all supposed to be using Moterolas, SPARCS, MIPS or something like it by '95 and have all this Intel crap as just a memory. Hmmm, let me check my systems here, oh look what they have.

      Its going to take a hell of a lot more then just a beige PPC box to change the status quo.
      • In the early 90s Intel's dominance was just ramping up. Remember back then? The cheapest PC you could get cost $1500 and was a 33 MHz 486 with 4MB RAM.

        In 2004 it's going on 20 years. We all know that market leadership is temporary, it is inevitable that someone will knock Intel from the pedestal. The question is not if but when, and by whom.
    • by zpok ( 604055 ) on Wednesday November 24, 2004 @06:49AM (#10907981) Homepage
      Suppose a 90% Windows marketshare - and be very nice and political and give Linux and the Mac each 5%.

      So what you mean is the whole Linux 5% would switch over to PPC beige boxes?

      Considering the fact they already can today (well, beige is a bit out of the question, but Linux on PPC is a definite - and pretty cool - option today, and there's always Darwin, BSD and related options) don't you think that even a 5% increase of PPC's is far-fetched in this scenario?

      Or is Windows supposed to support IBM chips suddenly?

      Seriously, am I missing something?
    • >Remember that AMD pays royalties to Intel for every >chip it sells, which pretty much condemns them to >permanent second-place competitor.

      When or why would/does AMD have to pay Intel royalties? Is that still in effect or did it end with the AMD64's? I thought x86 in general was an open architecture, hense the tons of IBM-clones that hit the market. Remember reading once, that Intel specifically left x86 open, because the money was in software and not so much in the architecture, but that was 5-

  • This interview was absolutely fascinating. The comment I found most interesting was McAlpin's opinion that 128-bit processing won't be coming to PC's any time soon. Excellent choice...
    • Its just like 64 bit processing. What does it buy you? In 99.999% of the cases it means more crud to move around and less effecent use of memory. Going from 32 bits to 64 bits didn't buy as much as going from 16 to 32 did and going 64 to 128 is almost pointless. Now a 32 bit machine that can munch on 1024 bit data at a time in an effecent way would be useful but now they call that a "video card"

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