Seagate is now ramping up to mass produce a new 18 TB hard disk based on perpendicular recording. These should be widely available in Q2-2020.
In 2003, a 160 GB hard disk was about as big as they could make them. Now hard disks are 100 times as large. Capacity improvement have been much faster than semiconductor improvements.
At present the shop has a few 4 TB disks and one 8 TB disk. More 8 TB disks are being considered due to the relative low cost. Incrementally increasing disc capacity makes sense as redundant backups are helpful in the face of ransomware and other horrors. An old machine with some large disks can be fashioned into a cheap NAS easily.
The existing 4 TB disks appear to have 2 plates while the 8 TB disk has 4 plates. Increasing areal density is the only solution to keep the 4 plate design in place.
Later on in 2020, Seagate is expected to finally offer the first commercial HAMR hard disk. Seagate has been testing them for over 12 months now and so far they have held up well so they are now ramping up the first generation of them. HAMR is poised to reach 50 TB by 2026. Seagate is hoping to be able to eventually increase capacity even more as the HAMR technology matures.
Earlier Seagate suggested 60 TB would be achievable but it seems that capacity points may be slightly different depending in the platter materials and the ability to achieve a reasonable error control mechanism.
The shingled disks are still sold to data centers and consumers where archives are generally static. Backup archives are static and they tend to be ideal for shingled disks. Shingled disks are fast for reads but writes are a comparatively slow process.
Seagate suggests that PMR will peter out at about 20 TB late in 2020. To reach a higher capacity will force the HAMR hand into 2022-2023. The current 16 TB EXOS disk uses 9 plates to achieve its capacity. The existing 8 TB consumer class disk uses a more manageable 4 platters.
Actively updates games are better off on a SSD or perpendicular hard disks which can handle the demands. Old static games tend to be more archivable which the archive disk look attractive.
Seagate also has been developing a new dual actuator design. The goal is to boost throughput to blur the line between SATA SSD products and hard disks. Dual actuators improves seek times as well. Having two heads mean double the throughput is realized.