California-based hard disk drive (HDD) manufacturer HGST has taken the next step in data storage volumes with the 10 terabyte HDD, the world’s largest volume yet.

Largely developed in Japan, the HDD was pioneered using helium gas as the medium for the device’s internal atmosphere.

HGST broke the 4 terabyte barrier for data storage in 2013 by filling the HDD itself with helium gas and sealing it in, launching the 6 terabyte HDD. It’s latest HDD succeeds the fellow helium-filled 8 terabyte HDD introduced in 2014, making it the third generation product in the series.

To understand the technology behind HDD’s is to understand the magnitude of this breakthrough itself. There are currently two commonly used types of HDD, one having a disk diameter of 3.5 inches – used in major servers and data centres for large data storage – and one thinner, lighter HDD having a disk diameter of 2.5 inches, used mainly for personal computers, Blu-ray/DVD recorders, and car navigation equipment.

In general, the HDD has a structure like that of a traditional record player; when rapidly revolving, the internal disk utilises the flow of the air generated on the surface of the disk, causing the magnetic head of the HDD – like the needle on a record player – to levitate. Data is then read and recorded accordingly. However, for the housing surrounding the disk a standard of one inch is set for the 3.5 inch HDD – this causes problems in terms of how many internal disks can be stored in the device. In conventional HDD’s filled with air, only five disks could be storage. Further still, when used where the air was thin at a high altitude, sufficient buoyancy could not be obtained for reading and writing, and there was a notable performance drop-off as a result.

Therein lies helium as the solution. Due to the density of helium gas as 1/7th that of air, and with little resistance when revolving the disk at high speed, even if a thin disk is used, stable reading writing can be obtained with the magnetic head. This enabled the ability to store seven disks in the HDD, as well as resulting in 23% less power consumption due to the low viscosity of helium creating more efficient disk revolution. All of which paved the way for the development of the 10 terabyte HDD of today, achieving a 25% greater volume than before by combining shingled magnetic recording (SMR) with a large amount of helium gas.

For 3.5 inch HDD’s, speed in reading and writing data has been a key factor in the past. However, with the increasing demand for cloud storage and online back-ups, there is a growing drive for large storage volumes to match; reading and writing speed has become a secondary concern. The introduction of the 10 terabyte HDD is therefore considered a significant milestone in data storage.