With 10-platter conventionally recorded disk drives touting capacities of up to 20TB by 2021, the arrival of HAMR and MAMR drives could slip back to 2022.

Trendfocus, a research firm specialising in data storage, suggests the launch of conventional technology in 18TB capacities in the second half of 2020 could delay the adoption of shingled magnetic recording (SMR) until the following year. Such SMR drives would have a 20TB capacity.

Seagate's HAMR to drop in 2020: Multi-actuator disk drives on the way READ MORE

In a 4 October report to subscribers, Wells Fargo analyst Aaron Rakers said SMR nearline volumes remained low. Vendors must sort out their host-managed schemes to better meet performance requirements before large-scale adoption takes place, Trendfocus added.

In turn, this could shift HAMR/MAMR adoption to 2022.

In the meantime, disk manufacturers could add capacity by bringing 10-platter drives to market. An 18TB nine-platter drive would then become a 20TB 10-platter product, assuming no increase in areal density. All HDD manufacturers continue to assess backup plans for such 10-platter drives, Trendfocus said. That would imply they would arrive in 2021.

Spinning platters

Conventional disk drives use perpendicular magnetic recording technology. There is a limit to their areal density, and therefore capacity. This is caused by increasing recorded bit state unreliability. As the bit areas become smaller, with areal densities beyond 1,200Gb per square inch, binary value becomes harder and harder to read, and can reverse as the bits are prone to flip.

Seagate and Western Digital have turned to alternative technologies to increase capacity beyond this limit.

The Cupertino firm's HAMR (Heat-Assisted Magnetic Recording) and WD's MAMR (Microwave-Assisted Magnetic Recording) HDDs are classed as nearline drives, and rotate at 7,200rpm. They are filled with helium to allow thinner and more platters than air-filled disks – helium resistance is lower than air.

Seagate and Western Digital are currently making nine-platter drives. WD's DC H550 tops out at 18TB and the SMR DC H650 reaches 20TB. They use some aspects of WD's MAMR technology but are not full MAMR drives.

Seagate's Exos X16 is a 16TB, nine-platter conventionally recorded drive with 1,000Gb per square inch area density. The company expects to introduce 18TB conventional HAMR drives and 20TB SMR HAMR drives with production ramping in the first half of 2020, both with nine platters. ®