6 ms·

Researchers Develop Transistor-Free Compute-in-Memory Architecture

colinthompson 4y ago
Are ferroelectric diodes more sensitive to external tampering than a “typical” memory circuit? As in, could a device like this be more easily “jammed” by a strong external electromagnetic source? That’s where my head went when reading about this circuit, but maybe it’s no less sensitive than “typical” circuitry?
- ilaksh 4y ago
  Compute-in-memory can increase computation performance by many orders of magnitude. The fact that most people just immediately try to find ways that these advancements can't work rather than trying to actually make them work is the reason that these things take so long to go from research to product. And it's also an example of the type of weak cognition that will mean un-augmented humans will be irrelevant within the next quarter century.
  - awesomeMilou 4y ago
    Cybernetics isn't even close to bringing any decent advantage to a healthy human physiology over the next 25 years wtf
    - ilaksh 4y ago
      It doesn't need to be close because these changes don't happen linearly. Look at for example computing in 1950 vs 1975 or 1975 vs 2000. With a new computing paradigm we should anticipate at least a 500X increase in compute per dollar over a period of 25 years. We also should anticipate quite a lot of progress in AI and brain-computer interfaces. Obviously what I suggested is speculation, but sensible speculation in these areas based on historical trends anticipates changes that are just as radical as the ones we have seen. "Moore's Law" came close to a wall a long time ago and has been braking hard. Compute-in-memory will allow us to speed up again.
  - meragrin_ 4y ago
    Isn't identifying flaws an important part of getting things to work?
    - ilaksh 4y ago
      Sure when you get to that stage. But instead of trying to make things work, people always try to shut down ideas just because they are new. Actually the bigger the advance, the harder people try to discount the ideas.
      - deleted 4y ago
        [deleted]
    - sroussey 4y ago
      Realistic optimists are required to effect change. Finding negatives is easy. Working through them to a positive result is gold.
- cogman10 4y ago
  > Are ferroelectric diodes more sensitive to external tampering than a “typical” memory circuit? Possibly? But the solution would be to put a Faraday cage around the memory. Something that effectively already happens when you have a heat sink on your memory. But further, you also have steal case surrounding your memory that helps there.
  - whatshisface 4y ago
    Although high permeability materials can route field lines around things to a certain extent, you can't get the kind of total magnetic shielding you'd want to say, protect a floppy disk from a strong magnet, without superconductors.
    - metadat 4y ago
      Why is this?
      - whatshisface 4y ago
        Conductors shield against electric fields and also catch EM radiation because it involves both E and M fields, but magnetic shielding relies on something analogous to electric polarization and consequently is more difficult.
  - amelius 4y ago
    A metal case is not an obstruction for a static magnetic field.
bilsbie 4y ago
I feel like this could be a really big deal?
- colonelpopcorn 4y ago
  It seems much more viable as an alternative to transistors than fiber optics does.
  - oh_my_goodness 4y ago
    Fiber optics is a fantastic alternative to copper cable. Has anyone claimed it's a reasonable alternative to transistors?
obblekk 4y ago
Exciting times. I wonder how scalable the materials tech is here. In the past basically everything lost to Dennard scaling of silicon transistors. Then everything lost to massive capital spend to scale silicon transistors via other optimizations. Now that we’ve clearly started hitting a wall (see Nvidia CEO recent statement on hardware no longer getting cheaper each cycle), these alternative paths may actually be able to compete on their own exponential learning curve. That would further hurt silicon transistor scaling as manufacturers like TSCM shifted resources toward new materials scaling, creating a strong positive feedback loop. As long as there’s some amount of scaling learning curve in a new material, it seems like the markets will shift rapidly (best guess 5-10 years) whereas before nothing could catch the exponential learning of silicon transistors.
hoosieree 4y ago
Non-von Neumann architectures have a lot of catching up to do on the software side. Nearly every mainstream programming language has "get one thing from memory, compute on it, put it back" semantics.
- naasking 4y ago
  Plenty don't though, like functional programming and relational databases. They're common enough these days.
  - chowells 4y ago
    Eh. Most functional languages actually serialize operations pretty linearly in their default evaluation model, which is why they have explicit constructs for parallelism and concurrency. There are some languages that are intended to parallelize implicitly, though. They tend to use keywords like "data-parallel" and "array language" to describe themselves. Futhark is a good example: https://futhark-lang.org/ https://futhark-lang.org/
    - naasking 4y ago
      > Most functional languages actually serialize operations pretty linearly in their default evaluation model, which is why they have explicit constructs for parallelism and concurrency. Yes, but evaluation models can adapt easier when the language does not have explicit mutation, so there's less "catching up" to do for functional languages. Also concurrent programming will always require a separate class of constructs from parallelism. There's also: https://wiki.haskell.org/GHC/Data_Parallel_Haskell https://wiki.haskell.org/GHC/Data_Parallel_Haskell
      - chowells 4y ago
        Data Parallel Haskell has been deprecated since roughly when I started using Haskell. It's basically seen as a failed experiment.
    - hoosieree 4y ago
FunnyBadger 4y ago
marshray 4y ago
Gain is an essential property of transistor-like circuit elements. Does this have the capability to amplify or oscillate? This seems more analogous to the old core memory or diode-based ROM.
solsane 4y ago
Based on the diagram this does matmul like a resistive crossbar array (something like https://arxiv.org/pdf/1410.2031.pdf https://arxiv.org/pdf/1410.2031.pdf). Talked about this in a ‘neuroprocessor’ class I took at uni. It’s practically ‘free’ since you perform multiplication by applying resistance to a current, and kirchoff’s law results in a sumnation of currents. Very elegant in concept. That being said, when scaling this approach, I recall one paper saying they had serious issues with signal integrity, in part from analog process mismatch. If this AlScN approach addresses that this would be really big. I’m interested to see if this can scale beyond a small model like mnist and also about how they map the weights.
- rowanG077 4y ago
  It's basic analog computing. However the 4-bit resolution is incredibly limiting. It's also not free since there will still be a setup and hold time you need to reach. Probably more power efficient but not free.
teleforce 4y ago
Previous HN discussions on the same topic: Rethinking the Computer Chip in the Age of AI: https://news.ycombinator.com/item?id=33129026 https://news.ycombinator.com/item?id=33129026
oh_my_goodness 4y ago
I guess for some people it'll always be 1987.

Are ferroelectric diodes more sensitive to external tampering than a “typical” memory circuit? As in, could a device like this be more easily “jammed” by a strong external electromagnetic source? That’s where my head went when reading about this circuit, but maybe it’s no less sensitive than “typical” circuitry?

ilaksh 4y ago
Compute-in-memory can increase computation performance by many orders of magnitude. The fact that most people just immediately try to find ways that these advancements can't work rather than trying to actually make them work is the reason that these things take so long to go from research to product. And it's also an example of the type of weak cognition that will mean un-augmented humans will be irrelevant within the next quarter century.
- awesomeMilou 4y ago
  Cybernetics isn't even close to bringing any decent advantage to a healthy human physiology over the next 25 years wtf
  - ilaksh 4y ago
    It doesn't need to be close because these changes don't happen linearly. Look at for example computing in 1950 vs 1975 or 1975 vs 2000. With a new computing paradigm we should anticipate at least a 500X increase in compute per dollar over a period of 25 years. We also should anticipate quite a lot of progress in AI and brain-computer interfaces. Obviously what I suggested is speculation, but sensible speculation in these areas based on historical trends anticipates changes that are just as radical as the ones we have seen. "Moore's Law" came close to a wall a long time ago and has been braking hard. Compute-in-memory will allow us to speed up again.
- meragrin_ 4y ago
  Isn't identifying flaws an important part of getting things to work?
  - ilaksh 4y ago
    Sure when you get to that stage. But instead of trying to make things work, people always try to shut down ideas just because they are new. Actually the bigger the advance, the harder people try to discount the ideas.
    - deleted 4y ago
      [deleted]
  - sroussey 4y ago
    Realistic optimists are required to effect change. Finding negatives is easy. Working through them to a positive result is gold.
cogman10 4y ago
> Are ferroelectric diodes more sensitive to external tampering than a “typical” memory circuit? Possibly? But the solution would be to put a Faraday cage around the memory. Something that effectively already happens when you have a heat sink on your memory. But further, you also have steal case surrounding your memory that helps there.
- whatshisface 4y ago
  Although high permeability materials can route field lines around things to a certain extent, you can't get the kind of total magnetic shielding you'd want to say, protect a floppy disk from a strong magnet, without superconductors.
  - metadat 4y ago
    Why is this?
    - whatshisface 4y ago
      Conductors shield against electric fields and also catch EM radiation because it involves both E and M fields, but magnetic shielding relies on something analogous to electric polarization and consequently is more difficult.
- amelius 4y ago
  A metal case is not an obstruction for a static magnetic field.

bilsbie 4y ago

I feel like this could be a really big deal?

colonelpopcorn 4y ago
It seems much more viable as an alternative to transistors than fiber optics does.
- oh_my_goodness 4y ago
  Fiber optics is a fantastic alternative to copper cable. Has anyone claimed it's a reasonable alternative to transistors?

obblekk 4y ago

Exciting times. I wonder how scalable the materials tech is here. In the past basically everything lost to Dennard scaling of silicon transistors. Then everything lost to massive capital spend to scale silicon transistors via other optimizations. Now that we’ve clearly started hitting a wall (see Nvidia CEO recent statement on hardware no longer getting cheaper each cycle), these alternative paths may actually be able to compete on their own exponential learning curve. That would further hurt silicon transistor scaling as manufacturers like TSCM shifted resources toward new materials scaling, creating a strong positive feedback loop. As long as there’s some amount of scaling learning curve in a new material, it seems like the markets will shift rapidly (best guess 5-10 years) whereas before nothing could catch the exponential learning of silicon transistors.

hoosieree 4y ago

Non-von Neumann architectures have a lot of catching up to do on the software side. Nearly every mainstream programming language has "get one thing from memory, compute on it, put it back" semantics.

naasking 4y ago
Plenty don't though, like functional programming and relational databases. They're common enough these days.
- chowells 4y ago
  Eh. Most functional languages actually serialize operations pretty linearly in their default evaluation model, which is why they have explicit constructs for parallelism and concurrency. There are some languages that are intended to parallelize implicitly, though. They tend to use keywords like "data-parallel" and "array language" to describe themselves. Futhark is a good example: https://futhark-lang.org/ https://futhark-lang.org/
  - naasking 4y ago
    > Most functional languages actually serialize operations pretty linearly in their default evaluation model, which is why they have explicit constructs for parallelism and concurrency. Yes, but evaluation models can adapt easier when the language does not have explicit mutation, so there's less "catching up" to do for functional languages. Also concurrent programming will always require a separate class of constructs from parallelism. There's also: https://wiki.haskell.org/GHC/Data_Parallel_Haskell https://wiki.haskell.org/GHC/Data_Parallel_Haskell
    - chowells 4y ago
      Data Parallel Haskell has been deprecated since roughly when I started using Haskell. It's basically seen as a failed experiment.
  - hoosieree 4y ago

FunnyBadger 4y ago

marshray 4y ago

Gain is an essential property of transistor-like circuit elements. Does this have the capability to amplify or oscillate? This seems more analogous to the old core memory or diode-based ROM.

solsane 4y ago

Based on the diagram this does matmul like a resistive crossbar array (something like https://arxiv.org/pdf/1410.2031.pdf https://arxiv.org/pdf/1410.2031.pdf). Talked about this in a ‘neuroprocessor’ class I took at uni. It’s practically ‘free’ since you perform multiplication by applying resistance to a current, and kirchoff’s law results in a sumnation of currents. Very elegant in concept. That being said, when scaling this approach, I recall one paper saying they had serious issues with signal integrity, in part from analog process mismatch. If this AlScN approach addresses that this would be really big. I’m interested to see if this can scale beyond a small model like mnist and also about how they map the weights.

rowanG077 4y ago
It's basic analog computing. However the 4-bit resolution is incredibly limiting. It's also not free since there will still be a setup and hold time you need to reach. Probably more power efficient but not free.

teleforce 4y ago

Previous HN discussions on the same topic: Rethinking the Computer Chip in the Age of AI: https://news.ycombinator.com/item?id=33129026 https://news.ycombinator.com/item?id=33129026

oh_my_goodness 4y ago

I guess for some people it'll always be 1987.