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Chips That Flow With Probabilities, Not Bits
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."
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.
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.
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.