Enlarge / This cutaway view of a Western Digital 18TB Gold drive shows off its nine platters and triple-stage actuators. (credit: Western Digital) Earlier this month, Western Digital announced retail availability of its Gold 16TB and 18TB CMR drives, as well as an upcoming 20TB Ultrastar SMR drive. These nine-platter disks are the largest individual hard drives widely available today. Earlier this year, rival drive vendor Seagate promised to deliver 18TB and 20TB drives in 2020, but they have not yet materialized in retail channels.