Western Digital has officially taken the wraps off 16TB and 18TB Gold enterprise-class hard drives. The company is also making Ultrastar 16TB and 18TB versions more widely available and said today a 20TB Ultrastar drive should ship next quarter.
The WD Gold family are conventional magnetic recording (CMR) drive and previously topped out at 14TB. The range is designed for enterprise-class server and storage systems and so carries a five-year warranty. Unlike their Ultrastar counterparts, they feature a SATA interface only.
The 18TB drive data transfer rate is 269MB/s, and the 16TB drive is 262MB/s. Both have 512MB cache buffers. WD Gold drives handle workloads up to 550TB per year, and are rated at up to 2.5M hours MTBF.
Ultrastar DC HC550
WD said today that the Ultrastar DC HC550 is now available for “cloud, large enterprise customers and other data center architects” in 16TB and 18TB capacities. Select hyperscale and enterprise OEM customers have been able to buy the drive since March.
Like the Gold family, the DC HC550 is a CMR drive, but is available with either SATA 6Gb/s or SAS 12Gb/s host interfaces and includes a 512MB cache buffer. According to WD, sustained transfer rates for these models are 257MB/s for the 18TB capacity, and 250MB/s for the 16TB.
WD also has a 20TB Ultrastar disk drive, the DC HC650. This is currently shipping for qualification by OEMs and is expected to become generally available next quarter.
The 20TB Ultrastar DC HC650 range are host-managed SMR drives, which means they use shingled magnetic recording in order to deliver their full storage capacity. SMR, recently the cause of much controversy, takes advantage of the fact that disk write heads are wider than read heads to partially overlap tracks as they are written, enabling more tracks to be crammed onto each disk platter.
This complicates matters when blocks have to be rewritten, and so SMR drives are not recommended for random write use cases because the write performance can be unpredictable and much slower in comparison with a CMR drive.
Host-managed SMR means that all the complexity is handled by software in the host system rather than the drive itself. This means such drives must be used in systems or with applications that can manage them.
JBODs
WD today also updated its Ultrastar Data60 and Data102 JBODs, plus the Serv60+8 storage server with the enterprise-class 16TB and 18TB Ultrastar DC HC550 hard drives. Ultrastar platforms with upgrades that support the Ultrastar DC HC650 20TB SMR drives are expected to follow next quarter.
The Ultrastar Data60 and Data102 JBODs have up to 24 drive slots and are described as key elements of next-generation disaggregated storage and software-defined storage, while the Ultrastar Serv60+8 is a high-capacity hybrid storage server. Both lines are targeted at enterprise customers, OEMs, cloud service providers and integrators that require dense, shared HDD or hybrid storage.
