Memristor — 4th Basic Element of Circuits

esocid writes "Researchers at HP Labs have solved a decades-old mystery by proving the existence of a fourth basic element in integrated circuits that could make it possible to develop computers that turn on and off like an electric light. The memristor — short for memory resistor — could make it possible to develop far more energy-efficient computing systems with memories that retain information even after the power is off, so there's no wait for the system to boot up after turning the computer on. It may even be possible to create systems with some of the pattern-matching abilities of the human brain. Leon Chua, a distinguished faculty member at the University of California at Berkeley, initially theorized about and named the element in an academic paper published 37 years ago. Chua argued that the memristor was the fourth fundamental circuit element, along with the resistor, capacitor and inductor, and that it had properties that could not be duplicated by any combination of the other three elements."

Re:Sure, it's neat

[eebra82]

Practical use, probably 15 to 20 years.

Insanely expensive prototypes with virtually no functionality in modern use, probably 4 to 10 years.

To call it the forth element...

[mkiwi]

I wouldn't say this is the 4th basic circuit element- that is quite a stretch.

Basically you have Ohm's law which is v =Ri. There is a component for each variable: Capacitors for voltage, inductors for current, resistors for resistance. It is all there, in nice little differential equations.

Yes, this is a great discovery. But please stop with the sensationalist headlines. This is getting out of hand.

I'll admit I don't understand the classification

[Chris Burke]

I don't understand what makes it a "fundamental" part of a circuit, while say a diode or MOSFET isn't. You can't make a transistor out of resistors, capacitors, and inductors... That's why it always showed up as the magical "voltage-controlled current source" in entry-level circuit analysis courses. I thought the three classic "basic" elements were because they were just the simplest.

Or maybe they're "basic" because every circuit (that's not superconducting), whether or not it contains semiconductors or more exotic stuff, has some amount resistance, capacitance, and inductance. Even if you don't want it, in which case you call it "parasitic". I don't think you're going to accidentally create two separate layers of titanium oxide.

So while I get why this discovery is totally awesome, I don't get what they mean by "fourth fundamental circuit element". Anyone got the skinny?

What a non-article

[Moryath]

According to their description, it's a memory cell that retains information without needing power. In other words, non-volatile RAM. It actually (according to their description) looks pretty darn similar to FeRAM.

Of course, to "Read" this stuff, you have to pass current through it to measure its resistance... so then you have to refresh it back to state... not sure how serious the power savings can be compared to simply improving the power required for other memory devices there.

In fact, the whole article is a bit misleading. They've come up with a new "memory element", just like how FeRAM and MRAM and now PRAM are new memory elements jockeying for position, and each of those comes with the same pie-in-the-sky pronouncements: computers that retain state when turned off without needing to cache to disk, lower power consumption/resiliency, neural networks, blabbity blah blah blah.

Some of the real jokes come later - pattern recognition, facial recognition, etc. Those come from either improving your software, or actually making a non-binary machine so that it's easier to express multiple states, not from just having a new way to store the same data set.

In a way, the stuff in this article reminds me a lot of people eating with their butts [wikipedia.org].

might, might, might, could, could, could

[EmbeddedJanitor]

It is easy to make a whole lot of might and could style predictions for some discovery that works in a controlled lab environment, but it is a lot harder to deliver them in product form: reliable enough and low cost enough to be useful. The tecno development hiway is littered with technologies such as bubble memory that just never worked out.

We've had Non-volatile state storage for ages (eg. FeRAM and floating gates (as used in flash) and battery backed up RAM). State storage is only part of the picture.

Whatever the mechanism, freezing state is not sufficient to instantly boot a modern computer. Pretty much all modern computers have some communication with an external device that needs to be renegotiated and reconnected, be that a mouse, disk or network.

Re:Leakage Current?

[mollymoo]

I think where you're really going astray is in assuming that a system which doesn't typically need to perform a full reboot would somehow be incapable of doing so; you even imply OS developers might forget that's a requirement, which is a huge insult to every OS developer. Having a system be able to boot itself from a clean slate (as it would have to for a new install, replacement of memristor-RAM sticks etc.) is not only a blindingly obvious requirement, but code that would be required anyway to boot the first system. Of course they'll be able to perform a full reboot, even if doing so is not the default.

As to the comparison with hibernate, it sounds far more like suspend than hibernate. On a system with memristor-RAM everywhere, including the peripherals, suspend would be much simpler - you just stop the clocks and cut the power. You'd still need to code for the apparent huge shifts in external time suspending would produce, but you have to do that now, in addition to saving and restoring the internal state of peripherals and associated data structures.