A few years ago, many analysts and industry spokespersons predicted that by 2020 spinning disks would be completely replaced as storage media by solid-state drives (SSDs). It is now perfectly clear that this simply did not happen. The total amount of data generated and then stored has grown so much, beyond all expectations, and as a result hard drives (HDDs) still play a vital role in the global storage business. HDD customers can take advantage of high total capacity plus attractive cost-per-capacity features.
One of the reasons for the continued success of HDDs is the technical innovations that have been achieved in recent times. Capacity HDDs with conventional air-filled technology reached their limit at 10TB a few years ago. The use of helium-sealed fill allowed the implementation of thinner configurations, but accommodated more platters, increasing the storage capacity to 14 TB. Smarter readheads enabled smaller magnetic bits and higher density levels, resulting in capacities of 16 TB in the usual 3.5-inch form factor.
16TB is considered the current technology limit for perpendicular magnetic recording (PMR), which is also sometimes referred to as conventional magnetic recording (CMR). Bit densities that support capacities greater than 16 TB require much smaller write heads, but they cannot generate enough magnetic flux to flip the magnetic bits in the media. To address this, additional (non-magnetic) energy must be injected – a principle known as assisted magnetic recording. In 2021, Toshiba introduced its first-generation microwave-assisted magnetic recording technology (MAMR), which uses a microwave-generating element to control and bundle the magnetic flux. This allows even smaller magnetic areas per bit to be achieved, enabling higher densities to be achieved – enabling storage capacities of 18 TB to be achieved. Further generations of MAMR, combined with a larger magnetic surface and more platters, will soon bring +20TB capacities to single HDD units.
Another way to put more data on the same magnetic surface is to write the tracks “overlapping”, like clapboards on a roof. Data can still be read, but the rewrite requires all overlapping tracks to be read and rewritten, leading to a kind of ‘uncertain’ write behavior. HDD manufacturers have compensated for the performance drop with smart caching/buffering architectures. Though questioned in the past, SMR technology is now fully accepted in client drives, as the benefit of up to twice the capacity on the same physical resource is very attractive, and the smart cache/buffer architecture more than compensates for performance degradation for nearly all real-life workloads.
- Major Online Storage Deployments – Modern society depends on an ever-expanding cloud-based universe composed of mobile apps, streaming movie/music content, e-commerce platforms, social media activities, etc. All related information is stored in huge data center facilities, which depend on HDDs as their main storage base. Often, these HDDs are not managed by hardware controllers, but by a software-defined storage (SDS) approach. For large offline archives, tape storage is still popular – and even tape is currently seeing significant growth rates. As it turned out that HDDs should remain the basis for large active online storage reserves in recent years, suppliers have optimized their capacity HDDs (above 10TB) not only for increasing capacity, but also for faster speed. A large number of these HDDs, combined with an SSD cache, can deliver the increased performance and increased overall capacity at the economic cost required by today’s data storage.
- The Lifespan of External USB HDDs – While some client applications such as network video recorders (NVR) for surveillance applications and low cost desktop PCs are still built on HDD storage, by 2022 SSDs will have replaced traditional HDDs in almost all other client applications such as laptops, all-in-one PCs, compact PCs and game consoles. For example, while the older generations of business laptops were usually equipped with 1TB HDD storage capacity, this has not grown but rather decreased to 500GB SSD storage in today’s devices, when the total capacity demand is actually in the 2~4TB range. . reach. Thus, client devices have a clear need for external storage expansion, and external USB-connected HDDs in the capacity range from 2TB to 4TB are becoming more popular than ever before.
- Gaming – Previously, game consoles relied on 1TB HDD storage capacity. The adoption of SSDs did not bring an increase in capacity, with neither the Xbox Series X nor the PlayStation 5 offering 1TB (about 825GB), although the memory requirements of games have grown enormously. Popular game titles can easily take up 50 GB or more. To free up disk space on the game console and safely cache memory-hungry games, external USB-connected HDDs are now a common accessory. They score with larger capacities at lower prices compared to external SSDs. Where an external SSD with 2TB currently costs more than 200 euros, external USB HDDs with 4TB capacity are available for well under 100 euros.
HDD manufacturers such as Toshiba are supporting these trends by expanding the range of external USB HDDs beyond the standard generic USB storage products through recent launches of custom-enhanced storage devices for gaming.
- Supervision – Another important trend that should be mentioned is surveillance. Surveillance systems are no longer just used to secure private homes or large businesses. By interacting with AI technology, facial recognition and smart monitoring, modern surveillance systems can retrieve valuable data for more complex tasks. Evaluation of such data can give stores insight into their customers’ buying behavior, traffic flows can be better managed, municipal resources better allocated, etc. Still, the storage solutions that support such systems must operate with the highest degree of reliability on a 24/7 basis. . Since this data often comes in waves, systems are sure to experience significant peak loads. Manufacturers such as Toshiba have recognized the need to provide customized and reliable surveillance solutions for both smaller and larger operations.
- Network Attached Storage (NAS) – It’s actually not that new, but NAS certainly represents an ongoing trend to be aware of. NAS systems have proven to be the ‘jack of all trades’, they can be used for smart home applications, as media servers for music/video content, for small businesses and home offices (something that has obviously gained a lot more traction in the past 2 years). Still, it’s important to find the right setup here. For most home users, 2-bay systems will suffice, as they can already provide several TB of storage and protect against hard drive failure. Sold as empty enclosures, the user will have to equip most NAS systems with hard drives. In principle, the devices work with almost all SATA drives, but users should definitely choose a NAS-optimized solution, such as the N300 from Toshiba. To avoid data loss, it is recommended that the HDDs in a 2-bay NAS be set up as RAID 1. This means that the system will then store all data mirrored on both disks, thus taking advantage of redundancy. Regular data backup should not really be considered a trend, it is an absolute necessity.
Flexible external storage solutions play an important role in backup storage across the consumer sector. Storing such data externally frees up space on mobile devices and PCs, improving performance. Whether backing up home office projects or for photo archives, external storage solutions such as Toshiba’s Canvio Flex offer a wide range of connectivity options that allow for fast retrieval of securely stored data.
Even the hyped cryptocurrency applications based on proof-of-capacity confirmed the tiering concept of optimized storage for each application. Generating (or plotting) is usually done via (small) fast SSD storage resources, while the generated patterns are stored on cheap 2nd-tier HDD-based storage. Similar concepts are used in media applications (with rendering and post-processing on SSDs and mass storage on HDDs), science/IT (with raw data and archiving of results on HDDs and analysis on RAM or SSDs).
In summary, HDD and SSD will continue to coexist, and discussions about whether SSD will ever completely replace HDD have now ended. The world’s ever-growing need for more online storage capacity at low cost can only be feasibly solved by HDDs, ensuring their future for many years to come. In 2020, the entire storage component industry produced about 1200EB (that is 1,200,000 TB) of the total capacity. Only about 200EB of this was based on SSD technology, with the majority of 1000EB being delivered through HDDs. That corresponds to a ratio of 5:1. The cost per capacity of SSDs continues to fall, but so do HDD costs – due to the aforementioned technical advancements. The ratio of 5:1 is expected to drop to about 4:1 in terms of total capacity split between HDD and SSD, but as total storage capacity continues to grow almost exponentially, there will be greater demand for both technologies. As the saying goes, “the rising tide lifts all boats.”
Author: Rainer W. Kaese (Senior Manager Business Development Storage Products at Toshiba Electronics Europe)