• monocasa 9 months 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 9 months 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.

      • mepian 9 months 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.

        • chx 9 months 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.

          • martinpw 9 months 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 9 months 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 9 months 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 9 months 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.

              • senkora 9 months ago

                Now there will be a twinge of sadness whenever I read a paper beginning with “Since the end of Dennard scaling…”.

                • bjourne 9 months ago

                  "The end of Dennard scaling and the impending repeal of Moore's law" is very overused in very many papers. :)

                • cpldcpu 9 months 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)

                • danso 9 months 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...

                  • scrlk 9 months 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.

                    • declan_roberts 9 months 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 9 months ago

                        Roger Penrose is 93 and as sharp as a tack!

                        • mhh__ 9 months ago

                          Another: Ed Thorpe is similarly old and still going strong, last time I saw.

                          • declan_roberts 9 months ago

                            Built different.

                        • undefined 9 months ago
                          [deleted]
                          • brcmthrowaway 9 months ago

                            wasnt there a 98 year old who got their second nobel?

                          • ayaen 9 months 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...

                            • blisterpeanuts 9 months ago

                              Bob Dennard enjoyed Scottish country dancing, which is how I knew him. He was a kind and humble man. R.I.P.

                              • vinaypai 9 months ago

                                DRAM pioneers don't die, they just stop their refresh cycle.

                                • petabyt 9 months ago

                                  Previous discussion from 4 months ago: https://news.ycombinator.com/item?id=40276464

                                  • osnium123 9 months ago

                                    He passed away months ago. RIP. He seems like a class act from what I’ve heard.

                                    • pkphilip 9 months ago

                                      May his memory live on

                                      • snvzz 9 months ago

                                        Wonder if he had some choice words about ECC.

                                        • undefined 9 months ago
                                          [deleted]
                                          • littlestymaar 9 months ago

                                            Not to be confused with Bob Denard[1] with 1 “n”.

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

                                            • drzzhan 9 months ago

                                              RIP.

                                              • gjvc 9 months ago

                                                (April)

                                                • petesoper 9 months ago

                                                  "By the early 1970s, DRAM was standard in virtually all computers."

                                                  Perfect bullshit.