Initial research is revolving around increasing the density of flash memory, which isn't surprising as Fujio Masuoka – who invented flash memory when he was working at Toshiba – is one of the chief proponents. But benefits are expected across all types of silicon products, including CPUs.
Processors hit a clockspeed wall a few years ago, which forced a switch to a parallel multicore approach to boost computing speed instead. But a tenfold increase in frequency would still provide a proportional boost in computing performance.
Optical computers have also been touted as a future replacement for current silicon-based designs. However, photonic transistors would actually require more power than electronic ones. So, in reality, optical computing is not likely to be the future of supercomputing. However, an area where optics do win out is when data rates and distances rise, as less loss of data is incurred compared to electrical lines.
Optical fibre is already the main enabling technology of high-speed telecommunications, and optical Infiniband cabling has been shown to exceed its copper equivalent in performance. Now, optical connections are also starting to be considered for use inside the CPU.
In particular, the Optical Shared Memory Supercomputer Interconnect System (OSMOSIS), a joint project of Corning Incorporated and IBM, aims to create a photonic-switching fabric. This would provide high-speed switching and scheduling of all the CPUs in a massive parallel cluster.
The most recent results demonstrated the fastest optical packet switch in the world, with an aggregate capacity of 2.5Tbps. Another promising possibility for the future of a supercomputer CPU comes from a much more organic source: DNA.
A demonstration in 2002 by researchers from the Weizmann Institute of Science in Rehovot, Israel, showed off a example of DNA computing that gave a performance of 330 trillion OPS. Even now – six years later – this performance places it fourth in the TOP500 list, and astonishingly, this was achieved with a single DNA molecule. However, the technology is currently very limited in the kind of calculations it can perform, and it can only answer 'yes' or 'no' when asked a question.
The system isn't exactly a floating-point cruncher in the manner of traditional supercomputers, and it won't be making its way to a mainframe near you in the near future, but it could well come into its own at some point.
An even more esoteric answer to the problem of building a supercomputer comes from quantum physics. This is still a very new area, but small-scale calculations have been successfully demonstrated using the curious behaviour of matter at the quantum level, in particular entanglement and superposition. With entanglement, two or more objects have linked quantum states, meaning that when one changes, the other performs an identical transformation.
Superposition refers to the probabilistic way in which matter behaves at the quantum level. Taken together, these behaviours theoretically would allow quantum computers to perform calculations an order of magnitude quicker than traditional systems.
PFLOPS in your lounge
However, it's unlikely that any of these new CPU technologies will be making their way into supercomputing over the next few years. Developing a new and amazing processor design is great for the advancement of technology, but it must be realistic.
If the new design is 10 times faster, but a hundred times more expensive than designs derived from mainstream consumer products, then clusters of the latter will have a much more attractive price-performance proposition. This was the main reason why supercomputing hit a brick wall in the early 1990s, a period when many of the former big names were forced into bankruptcy.
Once upon a time, computer technology innovation flowed from the specialised high-end to the generalised consumer. But nowadays volume is a key requirement in order to provide the income necessary for the research and development of a new processor core design.
