Seagate has launched a pair of 20TB disks for immediate use. One model is the Exos server class disk and the other is the Iron Wolf series. Both disks are transferring data 16MB/sec faster than the WD drives of the same capacity.

Seagate’s Exos X20 enterprise HDD is designed for maximum storage capacity and the highest rack-space efficiency. Built with cloud storage in mind, the 20TB Exos X20 delivers performance for hyperscale data centers and massive scale-out applications. With low latency of 4.16ms and repeatable response times, Exos X20 provides enhanced caching that performs up to three times better than solutions that only utilize read or write caching. Exos X20 also delivers an increased sustained data rate (SDR) of up to 285 MB/s.

Seagate’s new IronWolf Pro 20TB HDD offers network attached storage (NAS)-optimized AgileArray™ technology to provide exceptional RAID reliability and compatibility during the heaviest NAS workloads that SMBs might require. Designed with built-in rotational vibration (RV) sensors, IronWolf Pro 20TB offers RV mitigation to provide reliable performance for NAS systems with little lag or downtime.

The Seagate drives only have a 256MB cache capacity, while WD’s 20TB pair are fitted with 512MB ones. It must be down to better caching software. Seagate said these new disks are not SMR or HAMR. Instead they are conventional 9 plate disks with 2.2TB per plate.

The Exos X20 is a 24×7 data centre drive with a 550TB/year workload rating while the IronWolf Pro is a NAS drive with a user workload limit of 300TB/year. They differ in their mean time before failure (MTBF) rating as well. The Exos is a 2.5 million hour MTBF while the IronWolf Pro makes do with 1.1 million hours.

The 20TB Exos costs $670 while the 20TB Iron Wolf Pro will set you back $650, which includes three years of Rescue Data recovery. Most likely most of the disks will be sold to Azure, Alphabet and AWS etc before they find their way into consume NAS boxes.

Toshiba is likely to surface with a 20TB disk some time in 2022. WD is also likely to surface with new media as well. The demand for more capacity has been insatiable.