Robert Dennard, DRAM Pioneer, has died
331 points by jnord a day ago | 27 comments
  • osnium123 a day ago |
    He passed away months ago. RIP. He seems like a class act from what I’ve heard.
  • declan_roberts a day ago |
    > 91

    I really hope I live as long as these guys. It's one thing to invent something useful, it's another to spend your life watching it grow.

    • adharmad a day ago |
      Roger Penrose is 93 and as sharp as a tack!
      • mhh__ a day ago |
        Another: Ed Thorpe is similarly old and still going strong, last time I saw.
        • declan_roberts 20 hours ago |
          Built different.
  • monocasa a day ago |
    This is the Dennard of Dennard Scaling, a chip scaling law that is arguably as important as Moore's Law.

    https://en.wikipedia.org/wiki/Dennard_scaling

    The end of Dennard scaling was why the Pentium 4 architecture was a dead end and never hit 10Ghz like it was supposed to, why the Cell processor never hit the 5Ghz it was supposed to, why we've been spending quite a bit of the transistor budget on more cores rather than a very fancy single CPU core of 10Bs of transistors, and why chips with lower thermal limits will see a lot of "dead silicon" where you can't actually light up the whole chip at once without melting it.

    • pclmulqdq a day ago |
      Dennard scaling, for people in the industry, was far more important than Moore's law when it was available.

      Moore made a high-level observation, but Dennard told you how to do it.

    • cpldcpu a day ago |
      Well, it's basically the technical implementation of Moore's law, since Moore's law is just an empirical observation. (And maybe also a self-fulfilling prophecy)
    • mepian a day ago |
      >The end of Dennard scaling was why the Pentium 4 architecture was a dead end and never hit 10Ghz like it was supposed to, why the Cell processor never hit the 5Ghz it was supposed to

      Around that time the PowerPC 970 aka G5 also failed to achieve 3 GHz, breaking the promise Steve Jobs publicly made at one of his keynotes for Apple.

    • senkora a day ago |
      Now there will be a twinge of sadness whenever I read a paper beginning with “Since the end of Dennard scaling…”.
      • bjourne 9 hours ago |
        "The end of Dennard scaling and the impending repeal of Moore's law" is very overused in very many papers. :)
    • martinpw a day ago |
      > The end of Dennard scaling was why the Pentium 4 architecture was a dead end and never hit 10Ghz like it was supposed to

      I've always been puzzled by this. Did Intel really not see this coming? I remember talking to Intel engineers way back when they were promising 10GHz in the near future - I think the codename at the time was Tejas. They seemed very confident. The architecture must have already been planned out - and yet it seems from the outside like the end of Dennard scaling was a total surprise to them?

      • throwup238 21 hours ago |
        Intel (and almost everyone else tbh) didn’t fully appreciate how Denard scaling would play out at smaller nodes. They expected to keep lowering the transistor threshold voltage alongside transistor size but that became increasingly difficult due to leakage currents.
        • osnium123 19 hours ago |
          They also played with tricks like strained silicon on 90nm and high-k metal gate in 45 nm in order to boost performance and lower leakage respectively.
      • Tuna-Fish 7 hours ago |
        It was a scaling law that had worked for three decades, and didn't show any signs of faltering. Even the most senior of the people building those designs had spent their entire careers in a world where it just was true.

        And then it went away in an instant.

    • chx 15 hours ago |
      But when Dennard Scaling was in full swing, it was glorious. It only took six years to go from the original Pentium 60Hz on March 22, 1993 to Pentium III 600 MHz on August 2, 1999 and just a year later you could buy a 1GHz one.
  • scrlk a day ago |
    RIP.

    I was surprised that it didn't get much attention on HN when the news broke back in April, considering Dennard's large contributions to technology.

  • gjvc a day ago |
    (April)
  • blisterpeanuts 21 hours ago |
    Bob Dennard enjoyed Scottish country dancing, which is how I knew him. He was a kind and humble man. R.I.P.
  • drzzhan 20 hours ago |
    RIP.
  • snvzz 20 hours ago |
    Wonder if he had some choice words about ECC.
  • petabyt 18 hours ago |
    Previous discussion from 4 months ago: https://news.ycombinator.com/item?id=40276464
  • pkphilip 17 hours ago |
    May his memory live on
  • danso 10 hours ago |
    Apparently he died 5 months ago, but seems to not have gotten a lot of notice on HN

    https://news.ycombinator.com/item?id=40276464

    Mainstream outlets did write obits at the time: https://www.nytimes.com/2024/05/16/technology/robert-dennard...

  • ayaen 10 hours ago |
    Maybe its just me but here are people who made the world around us possible, and yet theu go unnoticed, in shadows, we seriously should celebrate and discuss scientists and technologists more, there are so many out there as important as Einstein, Lorenz Feynman and yet no where to be found in todays culture...
  • vinaypai 8 hours ago |
    DRAM pioneers don't die, they just stop their refresh cycle.
  • littlestymaar 5 hours ago |
    Not to be confused with Bob Denard[1] with 1 “n”.

    https://en.m.wikipedia.org/wiki/Bob_Denard