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Crash course. The Memristor

November 2014

So long as technology continues to propel our daily lives forward, innovation will remain alive and well. Which is precisely why researchers and technologists are constantly working on developing the next emerging trend that will help address our most pressing challenges.
One such example is the Memristor, a breakthrough that packs some serious potential. The memristor is a new breed of technology that may lead to servers and other devices far more efficient than today’s machines.
But, what is the Memristor?
Demystifying the Memristor
The Memristor—short for memory resistor—is a new building block of computer processors that may make it possible. It’s a unique kind of resistor circuit that remembers the last voltage that has been applied to it, even after the power is turned off. This is achieved by removing electrons from oxides in the Memristor. This technology can make a faster, cheaper, replacement for DRAM, flash memory and even disk drives. By combining memory and storage, Memristors enable what we call “universal memory,” radically increasing computing efficiency, and speed.  
Another way to think of the Memristor is as a pipe that carries water, with the water being the electrical charge. The rate of the water flow is the electrical current, and the pressure at the input of the pipe is the voltage. The point of the Memristor is that the amount of electrical resistance of the pipe depends on how much current has flown through it in the past. So, the resistance depends on its memory, hence, “Memristor.” In a real Memristor, it’s the movement of ions over nanometer distances that creates this effect.
The history
First theorized in 1971 by Professor Leon Chua, a distinguished faculty member in the Electrical Engineering and Computer Sciences Department at the University of California Berkeley, the Memristor is the fourth fundamental circuit element alongside the resistor, capacitor, and inductor. Fabricated at the nanoscale in microchips, Memristor technology is set to revolutionize computing.
The involvement of HP Labs
Instances of Memristor-like behavior have been observed by researchers for more than 50 years, but it was difficult to prove the actual circuit element’s existence, primarily because Memristor-like behavior is much more noticeable in nanoscale devices.
Researchers at HP Labs were the first to understand that the Memristor-like behavior they were observing really was the result of actual memristance and “memristive behavior.” [1] What does that mean? Well, in layperson’s terms, they proved the existence of the fourth basic element, making it possible to develop computers that retain their current state even when the power is turned off. In addition to making them effectively immune to power cuts, there will be no more waiting for machines to boot up.
Earlier this summer, HP announced a research project to use Memristors at the core of an architecture it’s calling “The Machine,” which should be ready as soon as the end of the decade. The Machine will use electrons for processing, photons for communication, and ions for storage, and can scale from handheld to data center size, making it capable of completely replacing current computer architectures.

How could it help small businesses?
Computers today have to move data between as many as ten layers of memory and storage, from ultra-fast SRAM, to DRAM, to relatively slow Flash and hard drives, creating a major bottleneck for performance. But with Memristor technology, HP will be able to create a system that replaces this “memory hierarchy” with a universal memory pool, eliminating a bottleneck that is in virtually every computing device today, from smart watches to servers.
Another clear benefit of Memristor-based systems is that they wouldn’t require the time-consuming “boot-up” process that’s necessary in DRAM-based computers. Imagine a complete data center able to recover almost immediately from a power failure, a process that takes hours or days today.
But the most valuable applications that Memristor technology enables—petascale graph analytics, distributed mesh computing and possibly using Memristors as logic devices—are yet to come.
Primed for the future
With the majority of the researchers at HP Labs dedicated to working on The Machine, it’s clear that Memristor technology has the chance to change the shape of computing systems as we know it. How do you think your business will benefit?
More on Memristor
The Machine: A new kind of computer
The end of a necessary evil: Collapsing the memory hierarchy
Beyond DRAM and Flash: The end is nigh
[1] HP Memristor FAQ