In May we tested the first 4TB hard disks, the 7K4000 and 5K4000 from Hitachi. At the time we had hoped that the two other players, Seagate and Western Digital, would also come with their first 4TB disks. That took a lot longer than we expected, but WD does have its first 4TB on the market now, in the shape of the WD RE 4TB for servers. Hardware.Info tested it to find out what it's capable of.
Hitachi used five 800GB platters for its 4TB hard drive, but WD uses four 1TB platters. The higher data density could in theory improve the performance. WD does not yet have a consumer 4TB disk, but a Western Digital Caviar Black 4TB has been announced.
The WD RE we tested is an Enterprise disk, optimised and validated for workstations and servers in particular. It carries an Enterprise-worthy pricetag of £323, quite a bit higher than the £213 Hitachi 7K400.
The 7200rpm disk uses a Serial ATA 600 interface and has 64 MB of cache memory, and is also available as a SAS model. WD gives five years of warranty, and the MTBF of the enterprise disk is 1.2 million hours. The improved reliability is provided by things such as anti-vibration and by a technology that ensures that the read/write head never physically touches the platters. They also have a feature that prevents them from falling out of a RAID array when they are recovering data.