Re: In-Memory Computing

On 18/11/2024 19:09, Michael S wrote:

On Mon, 18 Nov 2024 15:25:37 -0000 (UTC)
John Levine <johnl@taugh.com> wrote:
 

According to Lawrence D'Oliveiro  <ldo@nz.invalid>:

On Sun, 17 Nov 2024 21:32:29 +0000, MitchAlsup1 wrote:
 

... doing arithmetic in ferrite cores has been around for a very
long time, indeed.

>
Memristors are a new kind of electronic component, where the
resistance is proportional to the integral of applied voltage over
time.

>
This is a rather capacious version of "new" since memristors were
invented in 1971.
>
My impression is that they are real, they work, but they don't work
well enough to replace conventional components.
>
There is a very long article about them in Wikipedia.

 My impression from Wikipedia article is different. Memristors are not
real.
I.e. there are no physical devices that approximate mathematical
abstraction proposed in 1971. There are some devices taht look like
that, but only before researcher starts to pay attention to details.
After researcher starts to pays attention to details it typically turns
out that device resistance does not really depend on charge, but on
something else that happens to correlate with charge on bigger or
smaller parts of characteristic curves.
 

All electronic devices are approximations.  There is no such thing as a pure resistor, or a pure capacitor, or pure inductor.  Current memristors are no different in principle, but are - for now, at least - poorer approximations than the more common components.  Whether they will ever be close enough to be of practical use, remains to be seen.

What does exist and does work and does not work well enough relatively
to conventional tech are various variants of ReRAM. But memory elements
of those various ReRAMs are *not* memristors. That applies as much to
HP's not quite working "memristor" ReRAM as to all others ReRAMs in
existence including those that work relatively better.
 

Yes, that is my understanding too - there are a variety of memory devices that have been made with different properties and niches, but I don't believe any of them are based on devices that are close enough to ideal memristors to justify using the term.