With Perpendicular Magnetic Recording (PMR) technology very close to the data density limit per platter, hard disk manufacturers are working on other recording methods to increase storage capacity. Both Shingled Magnetic Recording (SMR) and Heat-assisted Magnetic Recording (HAMR) promise higher storage capacity, but neither have been perfected enough to put into use.
HGST, a subsidiary of Western Digital, has unveiled a different technique to solve the capacity problem which involves using helium instead of air in the hard disk. Helium has the advantage of being a far less dense gas, greatly reducing drag and vibrations, while also providing better thermal conductivity. This allows for thinner platters and for them to be spaced close together.
With thinner platters and platter spacing, up to 7 platters can be used instead of the current limit of 5 with air filled HDDs, improving capacity by 40% and reducing power consumption by 23%. By using today's 1TB platters, 7 platters would give a hard disk capacity of 7TB.
HGST expects to bring Helium-filled hard disks to the market in 2013, however it is unclear whether this would be early or later in the year. At present, they are still working on a suitable casing that can be mass-produced since these must be both hermetically sealed and filled with helium, unlike existing hard disks that use a breather-hole to equalise the pressure.
The first Helium filled hard disks will have an SATA interface, with SAS interface models planned later on. HGST claims that these Helium-filled hard disks will deliver the same IOPS performance as current hard disks for the same spindle speed. So far no pricing has been announced, but with the more complicated mass-production, these hard disks will likely be considerably more expensive than current hard disks.
