Toshiba is using energy assist technology in its first 18TB disk drive. The MG09 – out later this year – will be its highest capacity HDD to date, but rivals Seagate and Western Digital are already shipping 20TB drives.
The MG09 is a 9-platter design in a 3.5-inch format helium-filled enclosure. It comes in 16TB and 18TB capacities, has a Marvell controller and preamplifier, spins at 7,200rpm, has a 550TB/year workload rating and features either a 12Gbit/s SAS or 6Gbit/s SATA interface.
The drive is an evolution of Toshiba’s MG08 series which tops out at 16TB. The MG09 data transfer speed is 268MiB/s (281MB/sec) – better than the MG08’s 262MiB/s (274MB/s).
The drive uses flux control – microwave assisted magnetic recording (FC-MAMR) energy assistance – to overcome the difficulty of writing data bits to a recording medium that strongly retains magnetic polarity at room temperature. This is similar to Western Digital’s microwave-assisted magnetic recording (MAMR) technology.
We note that WD has not yet actually launched a drive that uses full MAMR technology. The company’s 18TB uses a precursor of MAMR called partial microwave-assisted magnetic recording technology (ePMR) to increase write efficacy with a write bias current.
For its 20TB drive, Western Digital uses ePMR plus shingling. Shingled magnetic recording crams more read tracks on a platter than conventional disks and so increases drive capacity. However, this technique slows write performance compared to the conventional recording used in the Western Digital, Seagate and Toshiba 18TB drives, and Seagate’s 20TB drive.
Seagate has taken a different tack for its 20TB drives, using HAMR (Heat Assisted Magnetic Recording), using heat to overcome the same difficulty (which is technically known as high coercivity).
Sample shipments of Toshiba’s 18TB MG09 Series disk drive are expected to start at the end of March 2021.
