Slashdot Mirror

← Back to Stories (view on slashdot.org)

Chips That Flow With Probabilities, Not Bits

Posted by samzenpus on from the new-angle dept.

holy_calamity writes "Boston company Lyric Semiconductor has taken the wraps off a microchip designed for statistical calculations that eschews digital logic. It's still made from silicon transistors. But they are arranged gates that compute with analogue signals representing probabilities, not binary bits. That makes it easier to implement calculations of probabilities, says the company, which has a chip for correcting errors in flash memory claimed to be 30 times smaller than a digital logic-based equivalent."

9 of 153 comments (clear)

  1. Analog Computers by timgoh0 · · Score: 4, Insightful

    It would seem that they have reinvented the analog computer, but this time entirely on a chip. And probably (hopefully) with some logic that prevents errors due to natural processes like capacitive coupling.

    1. Re:Analog Computers by Anonymous Coward · · Score: 5, Informative

      No, it does. We aren't trying to reduce error in logic operations. We're passing analog values between one and zero into logic circuits. Literally, at the lowest level, the "bits" pumping through the chip are probabilities. It's not analog in the sense that we use op amps, we still use gates, but the inputs and ouptuts of the gates are probabilities, not hard bits.

  2. There are 10 kinds of people in the world.. by Deus.1.01 · · Score: 5, Funny

    12.5% that understands binary 87.5 that don't...

    --
    My -1 Troll is actually a +1 funny. And my -1 flame is actually a +1 insightfull.
    1. Re:There are 10 kinds of people in the world.. by Thanshin · · Score: 4, Funny

      Probably.

      User: Are we in the right road to the beach?
      Google maps: Probably.
      User: the fuck?... Is this the beach road or not.
      Google maps: I'd say yes...ish. Most likely. ...
      User: The road is cut! It ends like right here!
      Google maps: Let me change my first answer to "I wouldn't bet on it. Much. I wouldn't bet much on it. ... Ok no, it's not likely to be the road. I'm turning off now. Good luck!"

  3. Probability in computers: it's called a float by Z8 · · Score: 4, Insightful

    The article mentions Bayesian calculations. Can these computers really speed up those calculations? Nowadays Bayesian calculations usually involve thousands of iterations of a technique called Markov Chain Monte Carlo (MCMC) unless the distributions in question are conjugate priors. The simulation then converges to the right answer.

    The issue I see is that all these techniques are just math. They are either analytic (conjugate priors) or require strict error bounds in order get sensible answers (MCMC). There's no separate system of math that Bayesians use. Like many others, Bayesians just need quick reliable floating point mathematics. So anyway, I don't see how this can help Bayesian statisticians, unless it also revolutionizes engineering, physics, etc.

    1. Re:Probability in computers: it's called a float by Frequency+Domain · · Score: 4, Informative

      [...] Nowadays Bayesian calculations usually involve thousands of iterations[...]. The simulation then converges to the right answer.

      The convergence you refer to is asymptotic. In practice it takes about 10000 iterations to get around a 1% bound on a single probability point estimate, and a factor of a hundred for each order of magnitude improvement. On top of that, if you're dealing with multiple distributions the overall expectation is not just a simple function of the component expectations unless the whole system is linear, you need to use convolution to combine results. And on top of that, lots of interesting problems are based on order statistics, not means/expectations. Having hardware that correctly manipulates distributional behavior in a few CPU cycles would blow the doors off of MCMC.

  4. Re:1 AND 1 = 1 : 0.8 AND 0.6 = 0.7 by selven · · Score: 4, Insightful

    If 0.8 AND 0.6 = 0.7 (I assume you're taking the average here), then 1 AND 0 would be 0.5, when it's supposed to be 0. The only answers I would accept for 0.8 AND 0.6 are 0.6 (min) and 0.48 (multiplication). An OR gate is constructed by attaching NOT (1 - x here) gates to the inputs and output of an AND gate, yielding 0.8 or 0.92 depending on which rule you go with.

  5. The actual thesis by Mathiasdm · · Score: 4, Informative

    By Ben Vigoda, Co-Founder and CEO: http://phm.cba.mit.edu/theses/03.07.vigoda.pdf

    --
    Join the anonymous, help develop the network: http://www.i2p2.de
    1. Re:The actual thesis by Born2bwire · · Score: 4, Funny

      By Ben Vigoda, Co-Founder and CEO: http://phm.cba.mit.edu/theses/03.07.vigoda.pdf

      Huh, I thought he was dead.