Western Digital has unveiled an upgraded line of 1TB to 4TB 3.5-inch hard drives for data centres.

WD had released another 4TB enterprise hard drive, the Ultrastar 7K4000 made by its Hitachi Global Storage Technologies (HGST) unit, in April.

WD completed its acquisition of HGST, now known as Viviti Technologies Ltd., in March.

WD today expanded its enterprise-class storage offerings with the release of new WD RE SAS and WD RE SATA hard drives that offer capacities of up to 4TB, said to be the highest available capacity today.

The RE drives are available in 1TB, 2TB, 3TB and 4TB capacities for nearline SAS (serial-attached SCSI) and 2TB, 3TB and 4TB for drives based on the lower-performance SATA (serial ATA) specification.

The RE SAS drives have a sustained sequential data transfer rate of up to 182MB/s, while the RE SATA drives have a sustained sequential data transfer rate of up to 171MB/s.

Like the Ultrastar 7K4000 line, the new RE SAS and SATA 4TB drives, contain five 800GB platters.

Both the SAS and SATA drive products use the latest 6Gbps-interface specification.

Unlike the Ultrastar drives, the new RE SAS and SATA drives do not have a native encryption option. WD said it would be offering encryption on the RE SAS model in the future.

"The WD RE SAS and SATA 4TB drives are designed, tested and optimized for enterprise storage and applications, enabling 33% greater capacity than previously available drives and up to 2.4PB of raw capacity in a single enterprise rack," said Doug Pickford, a senior director of business marketing for WD.

Dell is one of WD's resellers offering the new drives in its PowerVault MD3 arrays, offering up to 240TB of capacity in a single array.

The new RE SAS and RE SATA drives offer a 1.4 million and 1.2 million hour mean time before failure, respectively. The 3.5-inch WD RE SAS and RE SATA hard drives are covered by a five-year limited warranty.

The new RE drives pricing schedule:

4TB RE SAS drive: $479

3TB RE SAS drive: $369

2TB RE SAS drive: $249

1TB RE SAS drive: $139

4TB RE SATA drive: $459

3TB RE SATA drive: $349

2TB RE SATA drive: $229