On Wednesday, Seagate announced it was shipping the world's first 4TB external hard drive in the form of the 4TB GoFlex Desk Drive, which offers a high speed USB 3.0 interface. Obviously looking to steal a bit of Seagate's thunder - or should that be Thunderbolt - the very next day Hitachi Global Storage Technologies (GST) demoed its own 4TB external hard drives at IBC 2011 in Amsterdam in a two-drive, 8TB, RAID 0, G-RAID unit with Thunderbolt, FireWire 800 and USB 2.0 ports.

In keeping with Seagate's GoFlex line, the new 4TB drive can be paired with an adapter base that can be swapped for bases providing different connectivity options. The included base features a four LED capacity gauge and USB 3.0 connectivity, but FireWire 800/USB 2.0 bases are also available - as is an adapter base that turns a GoFlex drive into a network drive. A Thunderbolt adapter base is reportedly also on the way (which is definitely something we'd like to see sooner rather than later). The drive is Windows and Mac OSX compatible and comes with automatic backup software for both OS's. It measures 158(H) x 124(W) x 44(L) mm (6.22 x 4.88 x 44 in) and weighs 1080g (2.38 lb).

Meanwhile, the Hitachi GST 8TB G-RAID drive on show at IBC 2011 packs two 4TB 7,200 RPM drives within its all-aluminum enclosure that acts as a heat sink and features a quiet fan. Aimed at the creative professional audio/video Mac market, the demoed unit boasts a Thunderbolt port offering transfer speeds of up to 10Gbps and comes configured for OS X, although it can be reformatted for Windows PCs. Hitachi GST will also offer single-drive 4TB G-DRIVE's with eSATA, FireWire 400 and 800, Thunderbolt and USB 2.0 interfaces - no USB 3.0 though.

Seagate's 4TB GoFlex Desk Drive is available from the Seagate site now for US$249.99, with a GoFlex Desk for Mac, which sports FireWire 800 and USB 2.0 connectivity, set to hit Apple stores by the end of the month.

Hitachi GST will begin shipping its 4TB-based G-RAID and single-drive G-DRIVE drives with eSATA, FireWire 800 and USB 2.0 ports in October, with the Thunderbolt-packing models shipping in Q4. Pricing is yet to be announced.