In August, Seagate revealed that it had started shipping its first 8TB hard drive. Details were scarce at the time, but the drive has finally appeared on Seagate's website along with fresh information on what makes it tick.

As we suspected this summer, the new Archive HDD family uses Shingled Magnetic Recording (SMR). Instead of laying down tracks side-by-side with space between them, SMR uses overlapping tracks that can be packed more tightly. Seagate credits this approach with a 25% increase in storage density.

The SMR promo video isn't quite as catchy the classic Get Perpendicular, but it illustrates the shingling approach nicely:

The Archive HDD family comes in 8TB, 6TB, and 5TB capacities. It packs "up to" 1.33TB per platter, suggesting the smaller sizes have lower areal densities. The 8TB and 6TB units stack six platters, while the 5TB has only four.

All of the Archive HDDs sport 6Gbps interfaces and 128MB DRAM caches. The datasheet doesn't detail the rotational speed, but this Amazon listing indicates that the platters spin at 5,900 RPM. These drives are designed for archival storage and cold data that's accessed infrequently, so performance isn't a primary concern.

The Archive HDDs are rated for 180TB of writes per year, and they're covered by a three-year warranty. That lone Amazon listing prices a 20-pack of 8TB drives at $5,336, which works out to $267 apiece. The seller behind that listing expects to have stock in early January.