The Shifting Definition and Sustainability of Moore's Law
A significant portion of the discussion centers on the precise definition of Moore's Law and its historical evolution, with many users pointing out that the commonly accepted understanding (doubling of transistor density every two years) is not the original formulation.
- "Roughly every two years, the density of transistors that can be fit onto a silicon chip doubles. This is Moore’s Law." > "No. Moore's law is not about density," CalChris argued. "It's just about the number of transistors on a chip. Yes, density increases but so does die size. Anyways, in Moore's own word: 'The complexity for minimum component costs has increased at a rate of roughly a factor of two per year.'"
- Symmetry also weighed in on the definitional debate: "That's a common misconception. Moore's 1965 paper was about economics but when the phrase 'Moore's Law was coined in 1975 it was referring to Dennard Scaling as a whole."
- avereveard echoed this sentiment, stating, "that isn't about transistor density, but power density, which is not the same as 'the density of transistors that can be fit onto a silicon chip doubles' the whole article takes off from a flawed and fantasious misinterpretation and argue against that self created windmill."
The sustainability of Moore's Law, regardless of its precise definition, is also a major theme:
- jama211 opened by stating, "Moore’s law has been unsustainable for 20 years, I remember Pentium 4’s with 4ghz. But that hasn’t seemed to matter in terms of real day to day performance improvements."
- mandmandam expressed a sentiment about not creating unnecessary caps: "I don't expect Moore's law to hold for ever either, but I don't believe in creating unnecessary caps."
- Conversely, matthewdgreen suggested, "I think you could very easily give a cap that hinges on our current understanding of basic physical limitations, and it would arrive surprisingly soon."
- However, mandmandam countered this by noting, "That's the thing about Moore's law - it has assumed from the beginning that our 'current understanding of basic physical limitations' is incomplete, and been proven correct on that front many times over."
The "Software is Getting Slower" Phenomenon (Wirth's Law)
A significant counterpoint to the idea of hardware limitations is the observation that software performance has not kept pace with hardware advancements, a concept often referred to as Wirth's Law.
- WillAdams cited this directly: "The corollary is Wirth's Law: 'software is getting slower more rapidly than hardware is becoming faster.'" He further elaborated by attributing part of the saying to Martin Reiser: "'The hope is that the progress in hardware will cure all software ills. However, a critical observer may observe that software manages to outgrow hardware in size and sluggishness.'"
- ReptileMan provided a historical example to support this: "God of war 2 was made on 300mhz cpu and 32mb of ram. We haven't been bound by moore's law because we just waste computing power because programmers are expensive. No one is trying to optimize nowadays except in very niche places. And when push comes to shove we just start wasting slightly less. Like adding a JIT to a script language 15 years too late."
- WillAdams also expressed a desire for more software optimization: "I wish that there would be more instances of developments like to Mac OS X 10.6, where rather than new features, the software was simply optimized for a given CPU architecture, and the focus was on improving performance."
The Economics and Consolidation of the Semiconductor Industry
The economic realities driving the semiconductor industry and the resulting market consolidation are highlighted as a key factor in the perceived slowdown or unsustainability of Moore's Law.
- flomo pointed to the economic underpinnings: "> Gordon Moore always emphasized that his “law” was fundamentally rooted in economics, not physics. Effectively, it was always more of a 'marketing law' than an engineering one. Semiconductor chips only had 18-36 months to reap big profits, so Intel tried to stay ahead of that curve."
- jama211 also observed this trend in the broader market: "This article makes some great points about the scaling cost and reduced market opportunity for there to be more than 2 or 3 makers in the market, but that’s a trend we’ve seen in every market in the world, to be honest I’m surprised it took this long to get there."
- The increasing cost and exclusivity of manufacturing facilities are also noted: > kristianp remarked, "Roughly every five years, the cost to build a factory for making such chips doubles, and the number of companies that can do it halves." He then speculated, "So we may have Apple and NVidia as the only ones that can afford to build a fab." > > mepian countered this financially: "They can't afford to tank their margins like that, investors would be rather unhappy."
Future Computing Paradigms and Alternative Pathways
The discussion also speculates on the future of computing, including the role of current technologies and the potential for entirely new approaches beyond traditional silicon-based transistors.
- HarHarVeryFunny predicted a continuation of current trends: "I think the future of compute will look much like today! Given the power and ubiquity of smart phones, most people don't need any other computer in their personal life." He also suggested, "The same is somewhat true for business use too, especially if compute-heavy AI use becomes more widespread - some functions local and the heavy work done in AI-ready datacenters."
- There's a suggestion that alternative computational models might emerge, drawing parallels with biological systems:
- noelwelsh noted the transistor counts in GPUs relative to the human brain: "Current GPUs have a comparable number of transistors (92.2 billion in the current NVidia Blackwell according to [link] to the number of neurons in human brains (about 90 billion according to Wikipedia). Brains consume less energy and do more, though transistors beat them on density. This suggests there are alternative pathways to performing computation that will scale better."
- jojobas offered a caveat to this comparison: "It takes many transistors to replicate a single neuron, they work very differently in terms of speed, there is no direct comparison."
- noelwelsh clarified his point: "The article is musing about medium terms difficulties on the current pathway for producing computation. I'm musing that perhaps we are on the wrong pathway for producing computation."
- Symmetry referenced fundamental physical limits: "Landauer's principle governs how efficient computation can be, but we might have to transition to something other than transistors to hit that limit."
Persistence of Performance Gains Despite Stagnating Moore's Law
Several users express the sentiment that despite the slowdown in the raw doubling of transistor counts, real-world performance has continued to improve through other means.
- jama211 initially stated, "But that hasn’t seemed to matter in terms of real day to day performance improvements."
- ggm-at-algebras elaborated on how performance gains are achieved: "More parallelism. Less clock. More l1 cache per CPU and less disk stalls. Are there plenty of tricks in the sea, when clockspeed goes flat?"
- on_the_train spoke to the ongoing efforts in development: "There are a lot of people working on all the mentioned problems - and on many many more."
The Nuance of "Laws" and Misinterpretations
The discussion highlights that "laws" in technology, like Moore's Law, are often observations, predictions, or economic drivers rather than immutable physical principles. The article itself is criticized by some for building its arguments on a misinterpretation.
- CalChris emphasized the distinction between density and transistor count.
- avereveard explicitly stated the article was based on a flawed premise: "the whole article takes off from a flawed and fantasious misinterpretation and argue against that self created windmill."
- adrianN made a distinction between physical and engineering limitations: "Our understanding of basic physical limits seems reasonably good and hasn't changed for a couple of generations. Our understanding of engineering limitations on the other hand is not so good and updated frequently."
- Teever posited that Moore's Law is more of an "economical or social observation than a physical one."