In 2008, scientists at HP invented a fourth fundamental component to join the resistor, capacitor, and inductor: the memristor. Theorized back in 1971, memristors showed promise in computing as they can be used to both build logic gates, the building blocks of processors, and also act as long-term storage.

At its HP Discover conference in Las Vegas today, HP announced an ambitious plan to use memristors to build a system, called simply "The Machine," shipping as soon as the end of the decade. By 2016, the company plans to have memristor-based DIMMs, which will combine the high storage densities of hard disks with the high performance of traditional DRAM.

John Sontag, vice president of HP Systems Research, said that The Machine would use "electrons for processing, photons for communication, and ions for storage." The electrons are found in conventional silicon processors, and the ions are found in the memristors. The photons are because the company wants to use optical interconnects in the system, built using silicon photonics technology. With silicon photonics, photons are generated on, and travel through, "circuits" etched onto silicon chips, enabling conventional chip manufacturing to construct optical parts. This allows the parts of the system using photons to be tightly integrated with the parts using electrons.

If HP can build such a computer, it may prove revolutionary. The memory hierarchy is, for many computing applications, the fundamental performance bottleneck. Memory can be very fast but very small, such as the cache on a processor, or very slow but very large, such as spinning hard disks. RAM (fast, small) and flash (slower but larger than RAM, faster but smaller than hard disk) fall somewhere in between. Shuffling data between these different kinds of memory, and ensuring that the right data is in the right place for optimal performance, is a significant bottleneck.

High-speed optical interconnects combined with memristor memory could shake all that up by alleviating, if not removing entirely, that size/performance trade-off. At Discover, HP said that this could enable, for example, databases that can handle hundreds of billions of updates per second.

Bloomberg Businessweek reports that work on The Machine started two years ago when Martin Fink was made head of HP Labs, the part of HP that conducts R&D and that invented memristors in the first place. Fink pitched the idea of this cutting edge machine to HP CEO Meg Whitman, saying that it would need about 75 percent of HP Labs' staff to be working on the project. Whitman agreed to it.

In tandem with the hardware development, HP is also working on a new operating system that'll be designed for machines that have vast amounts of near-instantly accessible persistent storage. Conventional operating systems aren't; they're built for the hierarchy of memory technologies that are found in current computers.

Fink told Bloomberg that The Machine isn't (yet) on any official HP product roadmaps; at its earliest, it might arrive in 2017, at its latest by 2020. Skepticism is warranted, as memristors have hitherto been only a research project. Turning them into a viable, potentially mass-produced product hasn't been done before, and making that transition is rarely trivial. Over the years all manner of exotic memory technologies have been heralded as the next big thing, but while some, such as Ferroelectric RAM have come to market in limited quantities, none have managed to displace conventional DRAM and NAND flash. Memristors could be the one to buck the trend, but that's by no means a certainty.