IBM recently stated that 2.5 quintillion bytes of data are created every day and that 90% of the world’s data has been created within the past several years.
A lot of focus has been put on processing that data and speeding up computation with more sophisticated algorithms or high-performance computing. One aspect of this issue that is sometimes overlooked is the technology being used to store the massive amount of data now being collected.
Engineers and designers developing devices for many applications are challenged by the issue of data storage. The increasing importance of power efficiency, fast read/write operations, reliability, capacity, and economy (how much each GB costs) are factors that change how we look at data storage.
As the IoT spreads and enables more in-depth data collection, we've seen improvements in extent memory technologies. SSDs, or Flash Memory, are low-power and compact data storage options that lean towards the more expensive side where more traditional HDDs give you more bang for your buck on capacity (but possibly less reliable because of the moving parts). In the more advanced realm, designers and manufacturers may be acutely aware of component supply issues, such as the current scarcity of NAND flash memory storage.
Let's take a look at some of the hardware associated with memory storage, both what's available and what's coming down the pipe.
A render of Seagate's multi-actuator HDD, which consists of two independent actuators. Image courtesy of Seagate.
Seagate is exploiting the concept of “parallelism” to increase read/write speed in traditional hard-drives. They accomplished this by using multi-actuator technology, in which two actuators with 16 read/write heads work independently to carry out operations. Both can be reading or writing at the same time or carrying out the opposite task. This doubles the speed for these operations.
Seagate has previously explored multi-actuator solutions for HDDs, but initially found it to be an ineffective solution due to increased complexity in design, increased materials required for manufacturing, and increased weight. However, HDDs are now cheap enough and come in high enough capacities that the added complexity of dual actuators becomes a viable solution.
The company sees multi-actuator HDDs being used in data centers, artificial intelligence, and IoT applications.
MAMR: Microwave-Assisted Magnetic Recording
MAMR increases coercivity of the disc being written to, allowing for higher granularity. Image courtesy of Western Digital Corp.
MAMR (microwave-assisted magnetic recording), invented by ECE professor Jimmy Zhu from Carnegie Mellon and developed/manufactured by Western Digital Corp, is a solution to expand capacity in HDDs. MAMR is said to be able to store 4TB of data in 1 square inch of space, with an expectation that HDDs can reach a capacity of 40TB by 2025.
This is made possible by a spin torque oscillator which records data at a high precision and density using generated microwave fields.
Western Digital is targeting big data applications and data centers with their materials based capacity solution.
HAMR: Heat-Assisted Magnetic Recording
Writing head for an HAMR HDD. Image courtesy of Regmedia.
HAMR (heat-assisted magnetic recording) is another capacity-focused solution, meant to increase density in HDDs. Just as the nomenclature suggests, HAMR uses a laser to heat the area of the disk which will have data written to it. This heating makes the material easier to magnetize so that data can be written in much finer resolution, increasing data density.
This technology takes advantage of a concept called coercivity, which is the ease in which magnetization can be changed. Before HAMR, the only way to increase coercivity and therefore increase the resolution of data writing, was to use an already highly coercive material. The coercivity of material is also related to temperature, which is where the heating laser comes in.
HAMR could possible write data at a density of 50TB per square inch and the required laser uses only a few miliwatts of data. This makes it an interesting high-capacity solution for many fields.
No HAMR HDDs have become commercially available yet since it seems that there are still design and manufacturing challenges. Seagate demonstrated HAMR HDDs being used in data servers 2015 and announced the first HAMR HDDs to be available in late 2018.
Helium Filled Harddrives
Helium-filled HDD takes a different approach to expand the capacity of hard drives. Photo by Lenny Sharp courtesy of Sandisk.
Helium-filled HDDs are another capacity solution, but in a different vein from HAMR and MAMR—instead, helium is used to cushion vibrations, smooth out movement among discs in an HDD, and cool the HDD, which allows for more discs to be stacked and used without issues. This also allows for more precise and granular data writing. The discs used are also thinner, providing even more opportunity to increase data density.
Helium is thinner than air, which is why it makes a good cushion and dampener. It's also fairly cheap to use. HGST, a subsidiary of Western Digital, has been developing helium HDDs for years, with consumer-available versions released in 2016. Seagate also offered their own helium-filled HDDs the same year.
Have you worked with any of these data storage technologies? Which do you think holds the most promise for your design needs? Share your experiences in the comments below.
Feature image courtesy of Seagate.