For many years IBM has developing Phase-change Memory (PCM) a non-volatile method of storing data optically. Last month IBM announced that they have been able to extend the storage capability of the method from storing a single bit per cell, now allowing 3 bits to be stored, which will allow them to create cheaper and higher density devices.
This technology which manipulates the behaviour of chalcogenide glass has already been used for storing data on rewriteable Blue-ray disks. It works by applying an electrical current to change each PCM cell to or from its amorphous or crystalline state, allowing a representation of 1’s and 0’s to be stored.
The major advantages PCM has over flash memory is that not only are the data transfer speed near the levels of DRAM but the reliability is a lot higher, reportedly allowing 10 million cycles of each cell, rather than 3,000 write cycles. Such advantages could be revolutionise the storage industry, especially for mobile devices, where the boot time could be significantly reduce while improving the reliability. IBM are predicting that it could be used for storing entire database in an enterprise environment, with hybrid devices a possibility, allowing time-critical servers to process queries at a much higher speed.
While this technology does not currently pose a threat to the SSD and HDD markets, it not difficult to imagine that although further advances are unlikely to challenge the overall capacity of these devices at least without a significant increase in density, PCM may become an integral part of hybrid data storage devices.