SSDs Not Expected to Completely Replace HDDs at Any Point

This article was written Rainer W. Kaese, senior manager business development storage products, Toshiba Electronics Europe.

In which applications are HDDs still indispensable?

Since the introduction of flash memory, the end of HDD has been predicted again and again – but the classic storage device persists and remains the standard in many application areas.

According to Trendfocus, 259 million HDDs were shipped last year – a case in point. Their total capacity reached 1.338ZB, an increase of almost one-third compared to 2020. Never before have HDDs been shipped with more combined storage capacity.

Here is Toshiba’s view on which HDDs are indispensable today and will remain so in the coming years.
• Online storage in core and cloud data centres: Digital services now permeate almost all companies and large parts of society. Whether it’s Industry 4.0 environments, connected vehicles, streaming platforms or social networks – the huge and ever-growing volumes of data are stored on HDDs in data centres. HDDs are simply the most economical medium for these large online storage facilities; their capacity is constantly increasing due to the advancement of technology, while the price per terabyte is continuously decreasing. Flash memory is much more expensive and could not be produced in sufficient quantities, so it is mainly used as a cache when the data throughput of HDD arrays is insufficient.
• Network storage in companies and households: NAS serve as central storage and backup storage for many small and medium-sized companies, but also in more and more households. There they take over tasks as media servers and control centres for the smart home. HDDs are the ideal storage medium for these versatile devices – not only for cost reasons. Moreover, they can comfortably handle the transfer speeds in most company and home networks, where the high performance of flash memory would only be noticeable when transferring very many small files. In this case a caching SSD, for which some NAS have a separate slot, is sufficient.
• Video surveillance: The market for video surveillance is booming because people’s need for security is growing, and the systems are becoming cheaper and cheaper, making them affordable for private users. The now mostly high-resolution cameras deliver a video stream that HDDs can store perfectly – sequential writing of data at high speed is one of their strengths, and even the parallel recording of several HD streams does not pose any problems. They also offer a lot of storage space at a low cost, making them ideal for the large amounts of data generated by modern 4K and 8K cameras.
• External storage for computer users and gamers: Flash memory has displaced the HDD from almost all client systems, but because the manufacturers of PCs, notebooks and games consoles often only install quite small SSDs for cost reasons, users today generally have less storage capacity available in the devices than in the HDD era. At the same time, their storage needs are increasing because, for example, private photo collections photo collections are growing and new more sophisticated games can take up several dozen gigabytes of storage space. Usually data will be stored externally in “the cloud”, but people may prefer to have access to locally situated storage – due to cost reasons or security concerns. External HDDs with 2 or 4TB are therefore extremely popular, and are a simple and inexpensive way for many users to expand their storage.
• Archiving: When it comes to long-term storage of data, HDDs are the storage medium of choice, along with tapes. HDDs are somewhat more expensive for the same capacity, but they score points for shorter access times when certain documents need to be retrieved for an audit. In addition, HDDs can use de-dupe mechanisms to reduce the amount of data to be archived, which can reduce costs, depending on the type of data.

“SSDs are not expected to completely replace HDDs at any point,” emphasises Kaese. “Since the need for storage space is growing virtually everywhere and only HDDs can deliver the high storage capacities at low costs that data centres, cloud and other application areas demand, both media will continue to coexist for years to come.”