Researchers, he said, are working on a hybrid specification called Storage Class Memory (SCM) that blurs the lines between memory and storage, so could be used for either.
There are a number of potential technologies that can be used in SCM, such as Magnetic RAM, Solid Electrolyte RAM, Resistive RAM and Organic and Polymer Memory.
But the technologies showing most potential are Magnetic Racetrack Memory (MRM) and Phase Change Memory. MRM is still at the early stages of development but is an ‘extremely promising technology’. Phase Change, he added, is the leading contender to be the first SCM.
By 2013, Eleftheriou believes that there will be a SCM that costs less than $1 per gigabyte and is scalable. Currently, solid state memory capacities are still relatively small, meaning that for easily accessible data, hard disk drives are a more attractive option.
Ultra High Areal Density, a Phase Change Memory, is expected to scale up to about 500GB and would have extremely fast access times, but 1 terrabyte is a ‘real challenge’.
While hard disk storage continues to be popular, the use of magnetic tape for archiving purposes has not died the expected death. Magnetic tape has very high storage capacities, is cheap and extremely energy efficient, so costs less to run. But its main disadvantage is that access times are slow.
Eleftheriou believes tape can be scaled to 100GB/sq in, giving it a 10-fold advantage over hard disk drives. ‘So tape may not be dead, it may find its place in archiving applications.’