Toshiba Electronics Europe has started shipping samples of its M12 Series 3.5-inch nearline hard disk drives, using Shingled Magnetic Recording to reach capacities between 30 and 34 TB. A Conventional Magnetic Recording variant offering up to 28 TB is expected to enter sampling in Q3 2026.
The announcement, timed to coincide with World Backup Day, reflects the steady upward pressure on storage density from hyperscale and cloud providers. AI training workloads, video distribution, and the general proliferation of cloud-hosted services continue to push data centre operators toward higher-capacity drives that can deliver more terabytes per rack unit without proportional increases in power consumption.
The M12 Series achieves its capacity gains through several engineering changes. Toshiba has moved from aluminium to glass disk substrates, which are thinner and more rigid, enabling the drives to accommodate 11 platters within the standard 3.5-inch enclosure. The drives combine helium-filled casings with Toshiba's proprietary Flux Control Microwave-Assisted Magnetic Recording (FC-MAMR) technology alongside SMR.
SMR increases recording density by overlapping data tracks, but this creates write amplification penalties for random workloads. The M12 Series uses a host-managed SMR architecture, placing the responsibility for data placement with the host system rather than the drive firmware. This approach suits the sequential, bulk-write patterns common in hyperscale environments but requires software stack support that not all deployments have in place.
On performance, Toshiba quotes a maximum sustained transfer rate of 282 MiB/s — roughly 8% higher than the previous generation — while power consumption per terabyte drops by approximately 18%. The drives are rated for continuous operation with a 550 TB annual workload and an MTTF of 2.5 million hours.
Toshiba has signalled that Heat Assisted Magnetic Recording and 12-disk configurations are next in its roadmap, having verified the 12-disk stacking technology in October 2025.
