HDD Manufacturers Turn to New Technologies to Drive Capacity
As the storage wars between SSDs and HDDs drag on, SSDs have seemed to be gaining a decisive upper hand. Companies like Toshiba, Seagate, and Western Digital have shown off their next-generation technologies like Energy-Assisted Magnetic Recording (EAMR, WD) and Microwave-Assisted Magnetic Recording (HAMR, Seagate), but both companies seem to be having trouble shipping drives in significant quantities.
One of the major questions facing the magnetic spinning industry is whether to push forward towards 10-platter designs. Those of you who last looked up from your SSD performance graphs when 5-platter drives were all the rage may be surprised, but we’re already up to nine platters. StorageNewsletter writes:
In recent weeks, though, supply chain chatter has signaled that 10-platter designs may emerge sooner than originally planned, with some information pointing to 10-disk designs to support 20TB CMR capacities as a possibility. Granted, these plans could change, depending on pre-MAMR/HAMR areal density achievements, and technologies such as Western Digital’s EAMR approach may be employed to raise drive capacities over the next gen to obviate the need for a tenth disk.
Ultra-thin substrates of less than 0.5mm are also under investigation. The new glass platters Seagate is adopting as part of its move to HAMR technology are thinner than aluminum, and therefore theoretically allow room to squeeze another platter in. Theoretically, even 11-12 platter designs might be possible. Statements from the glass substrate manufacturer Hoya back up this interest in thinner substrates.
The reason there’s interest in the higher platter counts is that HDD manufacturers can still drive absolute capacities higher, even if technologies like MAMR, HAMR, and EAMR all fail to materialize as quickly as originally anticipated. There seems to be some doubt as to whether Seagate and WD will hit their aggressive capacity ramps. COVID-19 has done little to help matters on this front.
A 12-platter drive with 2TB platters would have an unformatted capacity of 24TB — significantly larger than any drive currently available. StorageNewsletter initially thought 24TB drives would be in-market by 2022, but the company is a bit less certain of what kinds of technologies the spinning disk manufacturers will use to get there. These could be drives with higher platter counts and conventional technology, or HAMR / EAMR products with fewer platters and higher areal densities.
As for SSDs, research is continuing into Penta Level Cell (PLC, 5-bit) NAND. While it would have even lower performance and less endurance than its QLC counterpart, there are advanced storage concepts like Zoned Name Spaces for SSDs that are intended to reduce write amplification and could allow PLC drives to further chew into HDD’s capacity advantage.
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