The oldest gerbils probably think about magnetic tape in the context of data storage for Commodore VIC-20s and the like. The youngest gerbils probably think of tapes as the way their parents used to record TV shows before the days of online streaming and DVR boxes. Magnetic tape is alive and well in the realm of large-scale backup operations, and Sony and IBM have worked together to create a prototype system that can store a mammoth 330 TB of data on a single cartridge with a volume of one third of a liter. For comparison's sake, a standard 3.5" hard drive displaces about 0.4 L and currently tops out at a capacity of 12 TB.
Achieving the ludicrous 201 Gb/in² areal density needed to cram that much data into such a tiny volume requires closing the gap between the surface of the tape and the magnetic head. Sony contributed a new lubricant that bonds to the magnetic surface of the tape and reduces friction between the contact point of the magnetic head and the tape. IBM brought its 48-nm-wide-tunneling-magnetoresistive (TMR) read-write heads, advanced servo control technology, and signal processing algorithms that enable the high storage density.
The magnetic layer in the tape is also special. The prototype tapes have a magnetic layer that is applied using sputter deposition to achieve a more uniform crystalline structure. The sputtering method produces a nano-grained magnetic layer with an average grain size of 7 nm. Sony says this deposition method and a suite of other technologies allow packaging more than a kilometer (3280 ft) of tape inside a cartridge measuring 4.3" x 4.9" x 0.96" (or 11 cm x 13 cm x 25 cm).
Neither company provided any details about when to expect a product based on the new tech to hit the market, but when that happens, it will be in the realm of datacenter administrators with large budgets and data that cannot be lost under any circumstances. Users looking to back up their cat videos and gameplay footage will probably have to wait a bit longer.