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"The smallest gate was built with an AFM out ~7 atoms; that's about 8 orders of magnitude smaller than a transistor" I was thrown off by your statement, so her

by mrb 1y ago

"The smallest gate was built with an AFM out ~7 atoms; that's about 8 orders of magnitude smaller than a transistor" I was thrown off by your statement, so here are some numbers: a modern chip like Nvidia's GH100 manufactured at a 5 nm process is 80 billion gates in 814 mm². That means a gate is 100 nm wide which is the width of 500 silicon atoms. On a 2D area that's 250k atoms. I don't know the thickness but assuming it's also 500 atoms then a gate has a volume of 125 million atoms. So I guess you get your "8 orders of magnitude" difference if you compare the three-dimensional volume (7 atoms vs 125 million). But on one dimension it's only 2 orders of magnitude (7 atoms vs 500). And the semiconductor industry measures progress on one dimension so to me the "2 orders of magnitude" seems the more relevant comparison to make.

ZenoArrow 1y ago
You're missing the key point, which is that the size referenced as the semiconductor manufacturing node is no longer an accurate description of the true transistor size, it's more of a marketing term. Even if it's possible to build transistors that are 1.4nm in size (or smaller), that is not what "1.4nm" means in the context of this announcement. I get that this can be confusing, it's just a case of smoke and mirrors because Moore's Law is already dead and semiconductor manufacturers don't want to spook investors. The performance gains are still real, but the reasons for getting them are no longer as simple as shrinking transistor size. As for the true physical limits of transistor sizes, there are problems like quantum tunnelling that we aren't likely to overcome, so even if you can build a gate with 7 atoms, that doesn't mean it'll work effectively. Also note that "gate" does not necessarily mean "transistor".
- timschmidt 1y ago
  > Moore's law is dead People have said this for decades. Jim Keller believes otherwise and brought receipts: https://www.youtube.com/watch?v=oIG9ztQw2Gc https://www.youtube.com/watch?v=oIG9ztQw2Gc
  - SlowTao 1y ago
    Personally I wouldn't argue Moore's law is dead but I do wonder about the cost per chip. WE can still push smaller for a lot longer but the costs are starting to creep up a bit. I am not too worried though because adjusted for inflation, we are still saying a lot less for this tech than we were in pre-2000's tech. Economy of scale used to drop prices, complexity of manufacturing will slowly increase them again.
    - timschmidt 1y ago
      Similar concerns were expressed around the development of VLSI tooling in the '70s. We've been on this curve for a long time. I can speak with some experience that manufacturing of steel and wood products increases similarly in cost and complexity with scale. Beasts like these exist: https://en.wikipedia.org/wiki/Heavy_Press_Program https://en.wikipedia.org/wiki/Heavy_Press_Program As long as the scale of production is increasing, additional investments will be warranted.
      - SlowTao 1y ago
        That is very fair. We won't know when things finally tip over into a new state until it is in the rear view mirror.
- mrb 1y ago
  I know and acknowledged it: GH100 gates are 100nm wide despite the "5nm" process. We all know about this discrepancy. "Moore's Law is already dead" That's clearly false, have a quick look at this chart: https://semiconductor.substack.com/p/the-relentless-pursuit-of-moores https://semiconductor.substack.com/p/the-relentless-pursuit-...
  - ZenoArrow 1y ago
    > That's clearly false, have a quick look at this chart Feels like it's not detailed enough to make an assessment. For example, if die size is being increased to counter the lack of improvements from transistor shrinking, it may technically meet the criteria set out in Moore's Law, but not in the sense that most people use it as a yard stick for performance improvements.
    - godelski 1y ago
      > if die size is being increased to counter the lack of improvements from transistor shrinking This definitely doesn't fully explain everything that is happening. Die sizes aren't changing that fast. Even if it is a part, you're ignoring that it is still a difficult technical challenge. It it weren't we'd see much larger dies. We have a lot of infrastructure around these chips that we're stacking together and the biggest problem in supercomputing and data centers is I/O. People would love to have bigger chips. I mean that's a far better solution than a dual socket mobo.
      - ZenoArrow 1y ago
        > This definitely doesn't fully explain everything that is happening. Die sizes aren't changing that fast. Let's look at a real world comparison. Based on information I can find online... * Apple M1 silicon die was 118.91mm2, used TSMC 5nm process node, and had 16 billion transistors. * Apple M3 silicon die was 168mm2, used TSMC 3nm process node, and had 25 billion transistors. If you compare these two, you can see that the increased die size did allow for most of the improvements in transistor count. Even if it's not a completely like-for-like comparison, and is not necessarily always as straightforward as this, it's obvious to me that transistor count on it's own is a poor measure of semiconductor process improvements, and a much better measure is transistor density (e.g. comparing how many transistors can fit into a wafer of a fixed size, such as 100mm2).
- bradly 1y ago
  > You're missing the key point I think they understand the space well. What mrb is pointing out is that OP is comparing two different units. The 7 atoms is a count of atoms in a 3d space and is not size dimension. Comparing a count of atoms with physical size of a transistor is problematic.
- godelski 1y ago
  > You're missing the key point They're nitpicking. They also demonstrated knowledge of the very thing you're trying to explain to them. So if you think they are being rude or hostile to you, be aware that, even if unintentionally, you insulted them first. To be honest, even I feel a little offended because I don't know how you read that comment and come away thinking they don't know that 1) the 'x'nm number is not representative, 2) gains are coming from things other than literal physical size, 3) quantum tunneling. They actively demonstrated knowledge of the first two and enough that I suspect they understand the third. I mean it is a complex phenomena that few people understand in depth, but it is also pretty well known and many understand at a very high level. From a third party perspective: it comes off like you didn't read their comment. I think you're well intentioned, but stepped on a landmine.

by mrb 1y ago

ZenoArrow 1y ago

You're missing the key point, which is that the size referenced as the semiconductor manufacturing node is no longer an accurate description of the true transistor size, it's more of a marketing term. Even if it's possible to build transistors that are 1.4nm in size (or smaller), that is not what "1.4nm" means in the context of this announcement. I get that this can be confusing, it's just a case of smoke and mirrors because Moore's Law is already dead and semiconductor manufacturers don't want to spook investors. The performance gains are still real, but the reasons for getting them are no longer as simple as shrinking transistor size. As for the true physical limits of transistor sizes, there are problems like quantum tunnelling that we aren't likely to overcome, so even if you can build a gate with 7 atoms, that doesn't mean it'll work effectively. Also note that "gate" does not necessarily mean "transistor".

timschmidt 1y ago
> Moore's law is dead People have said this for decades. Jim Keller believes otherwise and brought receipts: https://www.youtube.com/watch?v=oIG9ztQw2Gc https://www.youtube.com/watch?v=oIG9ztQw2Gc
- SlowTao 1y ago
  Personally I wouldn't argue Moore's law is dead but I do wonder about the cost per chip. WE can still push smaller for a lot longer but the costs are starting to creep up a bit. I am not too worried though because adjusted for inflation, we are still saying a lot less for this tech than we were in pre-2000's tech. Economy of scale used to drop prices, complexity of manufacturing will slowly increase them again.
  - timschmidt 1y ago
    Similar concerns were expressed around the development of VLSI tooling in the '70s. We've been on this curve for a long time. I can speak with some experience that manufacturing of steel and wood products increases similarly in cost and complexity with scale. Beasts like these exist: https://en.wikipedia.org/wiki/Heavy_Press_Program https://en.wikipedia.org/wiki/Heavy_Press_Program As long as the scale of production is increasing, additional investments will be warranted.
    - SlowTao 1y ago
      That is very fair. We won't know when things finally tip over into a new state until it is in the rear view mirror.
mrb 1y ago
I know and acknowledged it: GH100 gates are 100nm wide despite the "5nm" process. We all know about this discrepancy. "Moore's Law is already dead" That's clearly false, have a quick look at this chart: https://semiconductor.substack.com/p/the-relentless-pursuit-of-moores https://semiconductor.substack.com/p/the-relentless-pursuit-...
- ZenoArrow 1y ago
  > That's clearly false, have a quick look at this chart Feels like it's not detailed enough to make an assessment. For example, if die size is being increased to counter the lack of improvements from transistor shrinking, it may technically meet the criteria set out in Moore's Law, but not in the sense that most people use it as a yard stick for performance improvements.
  - godelski 1y ago
    > if die size is being increased to counter the lack of improvements from transistor shrinking This definitely doesn't fully explain everything that is happening. Die sizes aren't changing that fast. Even if it is a part, you're ignoring that it is still a difficult technical challenge. It it weren't we'd see much larger dies. We have a lot of infrastructure around these chips that we're stacking together and the biggest problem in supercomputing and data centers is I/O. People would love to have bigger chips. I mean that's a far better solution than a dual socket mobo.
    - ZenoArrow 1y ago
      > This definitely doesn't fully explain everything that is happening. Die sizes aren't changing that fast. Let's look at a real world comparison. Based on information I can find online... * Apple M1 silicon die was 118.91mm2, used TSMC 5nm process node, and had 16 billion transistors. * Apple M3 silicon die was 168mm2, used TSMC 3nm process node, and had 25 billion transistors. If you compare these two, you can see that the increased die size did allow for most of the improvements in transistor count. Even if it's not a completely like-for-like comparison, and is not necessarily always as straightforward as this, it's obvious to me that transistor count on it's own is a poor measure of semiconductor process improvements, and a much better measure is transistor density (e.g. comparing how many transistors can fit into a wafer of a fixed size, such as 100mm2).
bradly 1y ago
> You're missing the key point I think they understand the space well. What mrb is pointing out is that OP is comparing two different units. The 7 atoms is a count of atoms in a 3d space and is not size dimension. Comparing a count of atoms with physical size of a transistor is problematic.
godelski 1y ago
> You're missing the key point They're nitpicking. They also demonstrated knowledge of the very thing you're trying to explain to them. So if you think they are being rude or hostile to you, be aware that, even if unintentionally, you insulted them first. To be honest, even I feel a little offended because I don't know how you read that comment and come away thinking they don't know that 1) the 'x'nm number is not representative, 2) gains are coming from things other than literal physical size, 3) quantum tunneling. They actively demonstrated knowledge of the first two and enough that I suspect they understand the third. I mean it is a complex phenomena that few people understand in depth, but it is also pretty well known and many understand at a very high level. From a third party perspective: it comes off like you didn't read their comment. I think you're well intentioned, but stepped on a landmine.