Toshiba is rolling out 5 TB HDDs for serious applications next month. Toshiba primarily caters to the enterprise and OEM market, offering products on the SAS interface and SATA in various sizes.
Toshiba's MG04 series will feature 5 TB models in 3.5" form factors, with SAS and SATA models for nearline and midline attachments. Intended for applications where storage density and performance are more important than frugality. 5 TB per drive allows for more storage in the same physical space. The 7200 RPM spindle speed should help deliver higher performance, if not lower power consumption. Most 7200 RPM HDDs have approximately the same power envelope, so making a leap to 5 TB disks can lower the power use per GB of capacity in a one-to-one replacement over smaller units.
The MG04 series also touts other enterprise feature options, like persistent write cache and instant secure erasure, allowing drives to be quickly wiped. All disks will use 4 KB advanced sector formats, while also carrying support to emulate 512 byte native sectors in older systems.
While there isn't any price information at this time, it's reasonable to expect enterprise pricing (meaning, comparatively expensive). Tack on higher performance options like persistent write caching, and it's bound to get pricier. However, features, reliabilty record, and power consumption tend to weigh far more heavily in enterprise calculus, moreso than consumer products. That makes it a far easier sell for businesses, but consumers may have to wait a little longer for 5 TB disks aimed squarely at them.
SAS is generally more expensive, but also far more robust than SATA. Both models rely on 6 Gb/s signaling, though it's unclear just how much performance will be on tap. All other things being equal, more expensive SAS disks tend to experience far fewer errors in large deployments, besting more cost effective drives by an order of magnitude in downtime-related functional failures. Whether this is due entirely to SAS signaling, and not lower pricing (and margins) on SATA products is unclear.
Interestingly, Seagate hasn't yet introducted their high-cap technology, shingled magnetic recording, which purportedly allows existing 4 TB disk technology to hit 5 TB by cleverly utilizing read and write track size disparity. Toshiba hasn't made it clear how they're getting 5 TB on the MG04 series -- which includes MG04SGA (SAS) and MG04AGA (SATA) models -- but we'll find out when we get review samples early next month.