Number three in the hard drive maker’s league, Toshiba, has announced products of 24TB and 28TB. These are the 24TB MG11, which is conventional magnetic recording (CMR) HDD technology, and the 28TB MA11, which uses shingled magnetic recording (SMR) technology.
Seagate was the first to market around a year ago with similar drives, the CMR 24TB Exos X24 and an SMR variant at 28TB. Western Digital followed at the end of 2023 with its Ultrastar DC HC580 (24TB) and HC680 (28TB SMR). Toshiba’s previous HDD flagship capacity-wise was the 22TB conventional MG10F.
Toshiba’s new MG11 and MA11 hard disk drives (HDDs) come in 3.5in form factor. They comprise 10 platters per HDD, are helium-filled, have 1GB of NAND flash as cache and revolve at 7,200rpm. That cache size allows for a maximum throughput of 309MBps. That compares to the Seagate and Western Digital products which have cache of 515MBps and top out at 295MBps and 298MBps respectively.
Toshiba hard drives use its exclusive FC-MAMR technology. This is flux-control microwave-assisted magnetic recording, in which writes are facilitated by changing the magnetic qualities of the disk platter by use of microwaves.
Without this mechanism, the magnetic field of the head – such as on a conventional HDD – is less precise and more extended. This means the data occupies a greater area, with less stored per track, so the total capacity is lower.
The MG11 can connect via 6Gbps SATA and 12Gbps SAS. The MA11 only offers 6Gbps SATA connectivity. That makes its throughput about half of the MG11, in the region of 150MBps.
Shingled magnetic recording technology superposes or overlaps successive data tracks in a pattern reminiscent of the way roof tiles overlap.
But SMR hard drives face a particular constraint because it’s not possible to modify the contents of a track without rewriting tracks around it. This means SMR drives can only really be used for data that’s written once-and-for-all, such as backups, archives or documents stored to be read-only.
SMR hard drives are commonly used by hyperscalers for cold storage services because they can employ the skills needed to deal with constraints that come with HDDs with superposed disk tracks.
In the coming weeks, Seagate is set to announce HDDs of the next generation, namely 30TB in conventional recording and 32TB SMR.
All that comes against a backdrop of spinning disk (SAS and SATA) hard drive prices that remain significantly less costly than flash drives.
HDD costs per gigabyte have held steady for the past year or so, and are currently at around $0.039/GB, compared with $0.085/GB for flash.
That cost per gigabyte for spinning disk was $0.041/GB in early April. The current average pricranges from $0.041/GB for SAS and $0.036/GB for SATA.
Earlier this year, Rainer Kaese, senior manager in business development for storage products at Toshiba Electronics Europe, told Computer Weekly in a podcast that he expected hard disk drives to reach capacities of 40TB or 50TB in the coming decades, with hundreds of terabytes possible but not necessarily commercially viable.