Comment by westurner
1 year ago
> Specifically, the researchers operate a transistor under what are called "punch-through conditions." This happens when charges build up in a semiconductor in a way that can allow bursts of current to cross through the transistor even when it's in the off state. Normally, this is considered a problem, so processors are made so that this doesn't occur. But the researchers recognized that a punch-through event would look a lot like the spike of a neuron's activity.
> The team found that, when set up to operate on the verge of punch-through mode, it was possible to use the gate voltage to control the charge build-up in the silicon, either shutting the device down or enabling the spikes of activity that mimic neurons. Adjustments to this voltage could allow different frequencies of spiking. Those adjustments could be made using spikes as well, essentially allowing spiking activity
> [...] All of this simply required standard transistors made with CMOS processes, so this is something that could potentially be put into practice fairly quickly.
ScholarlyArticle: "Synaptic and neural behaviours in a standard silicon transistor" (2025) https://www.nature.com/articles/s41586-025-08742-4
How do these compare to memristors?
Memristors: https://en.wikipedia.org/wiki/Memristor
From "A Chip Has Broken the Critical Barrier That Could Ultimately Begin the Singularity" (2025) https://www.aol.com/chip-broken-critical-barrier-could-17000... :
> Here we report an analogue computing platform based on a selector-less analogue memristor array. We use interfacial-type titanium oxide memristors with a gradual oxygen distribution that exhibit high reliability, high linearity, forming-free attribute and self-rectification. Our platform — which consists of a selector-less (one-memristor) 1 K (32 × 32) crossbar array, peripheral circuitry and digital controller — can run AI algorithms in the analogue domain by self-calibration without compensation operations or pretraining.
Can't these components model spreading activation?
Spreading activation: https://en.wikipedia.org/wiki/Spreading_activation
Memristor is cool, and it is all in one (including memory), but it is not standard CMOS process.
That is whole difference.
Any way, will be sort of CCD matrix to use any of these techs (may be something like modern Flash as storage, or DRAM cell with refresh), but CMOS is very straightforward to produce and to use.
Why I mention CCD - it is analog storage with multiple levels, organized as multiple lines with output line on one side. It could also be used as solid-state circular buffer to access separate cells.
So, these CMOS transistors will work as neuron, but weights will be stored as analog value in CCD.
Is that more debuggable?
Re: the Von Neumann bottleneck, debuggability, and I guess any form of computation in RAM; https://news.ycombinator.com/item?id=42312971
It seems like memristors have been n years away for quite awhile now; maybe like QC.
Wonder if these would work for spiking neural behavior with electronic transistors:
"Breakthrough in avalanche-based amorphization reduces data storage energy 1e-9" (2024) https://news.ycombinator.com/item?id=42318944
Cerebras WSE is probably the fastest RAM bus, though it's not really a bus it's just addressed multiple chips on the same wafer FWIU.
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