Seagate this week unveiled the industry’s first hard disk drive platform that uses heat-assisted media recording (HAMR). Tom’s Hardware:
The new Mozaic 3+ platform relies on several all-new technologies, including new media, new write and read heads, and a brand-new controller. The platform will be used for Seagate’s upcoming Exos hard drives for cloud datacenters with a 30TB capacity and higher. Heat-assisted magnetic recording is meant to radically increase areal recording density of magnetic media by making writes while the recording region is briefly heated to a point where its magnetic coercivity drops significantly.
Seagate’s Mozaic 3+ uses 10 glass disks with a magnetic layer consisting of an iron-platinum superlattice structure that ensures both longevity and smaller media grain size compared to typical HDD platters. To record the media, the platform uses a plasmonic writer sub-system with a vertically integrated nanophotonic laser that heats the media before writing. Because individual grains are so small with the new media, their individual magnetic signatures are lower, whereas magnetic inter-track interference (ITI) effect is somewhat higher. As a result, Seagate had to introduce its new Gen 7 Spintronic Reader, which features the “world’s smallest and most sensitive magnetic field reading sensors,” according to the company. Because Seagate’s new Mozaic 3+ platform deals with new media with a very small grain size, an all-new writer, and a reader that features multiple tiny magnetic field readers, it also requires a lot of compute horsepower to orchestrate the drive’s work. Therefore, Seagate has equipped with Mozaic 3+ platform with an all-new controller made on a 12nm fabrication process.
Abstract credit: https://hardware.slashdot.org/story/24/01/19/1149214/30tb-hard-drives-are-nearly-here
To be fair, I doubt that they were saying they didn’t believe drives could be that big. It’s that 5TB is an unusual size, and as far as I can tell only come in external drives. I personally have never seen one or even knew they existed until now, but I only buy bare drives.
It may very well be a 6TB with bad sectors
No, there are a few that I found once I went looking. One was a 2.5 inch which is likely used in external drives, the others were enterprise level drives. They are just not things I normally search for, but they do exist.
5TB is used in 2.5” form factors because it appears to cap out whatever manufacturing process they use for those. There’s no 6TB 2.5”s
There are no platter drives above 5TB. There are plenty of 2.5 inch SSDs available above that size. This is less a technical limitation and more of a business decision though.