Optical media: dead or alive?

Optical media is very much alive and thriving. It is entirely complementary to cloud, SSD and HDD storage because it has advantages that they don’t. That’s not to say they don’t have their place; they most certainly do; immediacy of access and potentially massive capacity being the two most obvious. They also have weaknesses which we’ll discover as we examine optical media usage.

A vast amount of digital data is being generated each year, a trend that shows no sign of stopping. According to IDC figures, in zettabytes (1ZB = 1,000,000,000,000,000,000,000 bytes) the global volume grew from 0.9ZB in 2008, 33ZB in 2018 and is expected to reach 175ZB in 2025. The trend is ever upwards, no matter what line of business you’re in.

Keeping all the data in computer hardware or in the cloud (which is usually other people’s computer hardware anyway) is an expensive way to preserve valuable information that’s not needed today but may be needed in the future. All companies are obliged to keep some data to comply with legislation and regulations. Some want to keep it for other historical reasons. Individuals, of course, like to preserve their bulky personal data such as music, photo collections and important documents. CDs, DVDs and Blu-ray discs offer different storage capacities, from 700MB to 100GB and keep their data in perfect condition.

Traditionally, corporate archives have been stored on magnetic tape, not least because of its vast capacity. What’s less well known is that the tapes need to be rewritten every few years, due to degradation of the magnetic recording. Also data on tapes is usually accessed serially which is fine for recovery of data stores but not so good if you want to access items more randomly. HDDs are electromechanical devices which makes their longevity somewhat unpredictable. And SSDs cannot be relied upon for long term storage. Just like tape, it’s best to refresh data on both HDDs and SSDs every two or three years. Alternatively, you can keep duplicate copies of data on different devices for good protection but this comes at significant extra expense.

Optical media improves all the time, in both reliability and capacity. Verbatim’s current top-of-the-range Blu-ray BDXL discs each store up to 100GB and will last hundreds of years without degradation. In fact, industry standard ISO/IEC 10995 tests gave them a mean lifetime of 1,332 years, with just 5% of discs showing signs of data loss after 667 years.

Because they’re inert, their storage requires nothing beyond a small amount of space. And, because of very strong and consistent recording standards, optical discs will remain readable for the foreseeable future. The important thing is to have a clear strategy with respect to which data you need to keep and to store it in a durable standard format (e.g. pdf, Jpeg, and so on.)

To answer the question posed in the headline: “Is optical media dead or alive?” The answer is, “Very much alive. And improving all the time.”