Solid state storage is fast but magnetic is still king in capacity. Seagate's latest announcement spans the enterprise storage needs from the Pulsar SSD to its near line storage Constellation. It addresses the full storage hierarchy. Many of these disks will wind up in embedded applications as well because of their performance and features. They are more durable than consumer disks.
The trend is definitely 6 Gibt/s SAS and 2.5-in drives. The 3.5-in drives are still found at the high capacity, near line storage. SATA is an option here here as well.
The latest products are grouped into three areas: solid state disks (SSD), fast SAS hard drives and near line storage. The SSDs are part of the Pulsar family. It comes in two flavors. The first is Pulsar XT.2 (Fig. 1). It is an SLC NAND-based SSD. It comes in capacities from 100 to 400 Gbytes. Performance is on the order of 48K/22K IOPS for random read/write. It supports up to 35 full drive writes per day and it comes with a 5 year warranty. This translates to a 24 petabyte (Pbyte) write lifetime.
The other SSD is Pulsar.2 that is based on MLC NAND flash. It comes in capacities from 100 to 800 Gbytes. It supports up to 10 full drive writes per day and it comes with a 3 year warranty. This translates to a 15 Pbyte write lifetime. The tradeoff is price, performance, and lifetime.
The Savvio 15K.3 (Fig. 2) and Savvio 10K.5 are 6 Gbit/s SAS hard drives. The names specify the rotational speed. The 15K drives come 146 Gbyte and 300 Gbyte capacities with a 2.5ms average read seek time. The 10K drives have a 300 Gbyte to 900 Gbyte capacity range. Seek times are a little longer starting at 3.4ms. These drives also available with a Fibre Channel although this more for transition support. SAS is definitely taken over the enterprise with SATA used in areas where cost is important and performance or reliability is less important.
Seagate had already delivered a 2.5-in 1 Tbyte Constellation drive. This time around they deliver the 3 Tybte Constellation ES.2 (Fig. 3). It comes in 6 Gbit/s SAS and SATA versions. The average read seek time is 8.5ms.
One of the new features in the Constellation ES.2 is RAID Rebuild. This is a rapid rebuild function that takes advantage of the fact that a drive has multiple heads. Typically one head will fail as a drive fails so the other heads can be used to read data as it is copied to a spare RAID drive. This feature requires driver and controller support.
One aspect that spans all the drives are security. Self encrypting drive (SED) support is available with instant drive sanitization in under a second. The SED drives use AES-256 encryption.
The SEDs also support T10 Protection Information (PI). PI is extra data associated with each sector. It requires driver and controller support but it provides app to disk security. This is a key advantage for the cloud especially when considering a multitier storage hierarchy.
Seagate is clearly targeting the enterprise space with these drives. They fit well into embedded applications because of their reliability and performance characteristics. The SED support is also becoming more important to embedded applications as well.