Not to be outdone by Seagate’s 4TB GoFlex Desk, Hitachi’s G-Technology unit has now unleashed a jumbo-sized external HDD of its own, with the 8TB, dual-drive G-RAID. Demoed at this week’s IBC conference in Amsterdam, the company’s new storage house consists of two 4TB drives nestled within an aluminum enclosure, each of which clocks in at 7,200 RPM. Configured for OS X, the G-RAID also sports a Thunderbolt port that offers transfer speeds of up to 10Gbps, though it can also support Windows with some simple reformatting. G-Technology will begin shipping its 4TB drives in October (with eSATA, FireWire 800 and USB 2.0 ports), whereas its “4TB-based” Thunderbolt-equipped drive won’t hit the market until Q4 — though it’s still unclear whether either model will ship as single drives, or as a two-headed, 8TB beast. Pricing remains a mystery for the moment, but you can find more details in the full PR, after the break.