Toshiba edging nearer to 26TB capacity nearline disk drives?

Japanese disk drive media manufacturer Showa Denko K K (SDK) is shipping 26TB capacity disk drive platters. It has not revealed its customer, but Toshiba uses Showa Denko platters in its nearline 3.5-inch disk drives.

Nearline disks are high-capacity (15TB-plus) drives spinning at 7.200rpm, typically with a SATA interface.

SDK says its new disk media supports energy-assisted magnetic recording and shingled magnetic recording (SMR) because its has fine crystals of magnetic substance on the aluminum platter surface. It includes technology to improve the media’s rewrite-cycle endurance. SDK says it produces disk platter media by growing epitaxial crystals at the atomic level, forming more than ten layers of ultra-thin films with a total film thickness of no more than 0.1μm.

SMR drives need host management of data writes to zones of overlapping write tracks – a data change in any part of the zone requires the whole zone to be copied, edited, and rewritten. This effectively limits their use to hyperscaler customers who can have their system software modified to manage SMR drives. Such drives are unlikely to appear in standard enterprise datacenters or video-surveillance farms or even desktop PCs, unless system software is altered to support them.

Like Western Digital, Toshiba uses energy-assisted recording to strengthen data writing in the very small bit areas of 18TB-plus drives. Its specific technology is called MAMR (microwave-assisted magnetic recording). Seagate has an alternate HAMR (heat-assisted magnetic recording) technology in development.

Western Digital and Seagate are shipping 20TB conventionally recorded (CMR) nearline drives with Toshiba at the 18TB level. Seagate is sample shipping a 20TB-plus drive with Western Digital sample shipping 22TB CMR drives and 26TB shingled magnetic recording (SMR) drives. SDK and Seagate are partnering to build HAMR disk drives.

Toshiba has a 20TB CMR HDD on its roadmap and a 26TB SMR drive. The Showa Denko 26TB HDD media news indicates that this could be announced for sample shipping quite soon.

We could see both Western Digital and Toshiba shipping 26TB SMR drives in the summer but not Seagate, unless its 20TB-plus drive has an SMR variant at the 26TB capacity level.

SDK said it plans to produce nearline disk drive media with a greater than 30TB capacity by the end of 2023.