by Kevin OBrien

Hitachi G-RAID With Thunderbolt Review (8TB)

Hitachi's G-Technology line of external hard drives has long been a favorite for creative professionals and others who generally need some combination of reliability, performance, capacity and redundancy. While Hitachi has several products in the G-Tech line that specialize in one or more of those qualities, their latest effort is an external storage generalist that can just about do it all. The G-RAID with Thunderbolt offers up to 4TB of capacity over two mirrored drives, or 8TB if configured for maximum throughput in RAID0 over Thunderbolt, while providing legendary reliability from Hitachi's latest Deskstar 7K4000 hard drives.

While the 4TB in RAID0 or 8TB spanned max capacity is great, the real highlight of course is the Thunderbolt interface, this is the first time Hitachi has used Thunderbolt in their G-Tech line. While Hitachi has never shied away from experimenting with new interfaces before, with Apple and Intel backing, Thunderbolt is here to stay for some time. And why not, Mac users have long deserved an interface that can deliver faster throughput than FireWire, in this case the G-RAID is capable of delivering over 300 MB/s read and write performance which is pretty impressive over a 4TB volume. 

Hitachi's G-Technology G-RAID with Thunderbolt family is currently available through Apple. They come in 4TB, 6TB and 8TB capacities with suggested pricing of $699.99, $849.99 and $999.99 respectively. Like most Thunderbolt solutions, Thunderbolt cables must be purchased seperately. G-RAID products carry a three year warranty and free technical support by reps experienced with content creation applications.

Hitachi G-RAID With Thunderbolt Specifications

  • Capacities
    • 4TB (GRATHNB40002BAB)
    • 6TB (GRATHNB60002BAB)
    • 8TB (GRATHNB80002BAB)
  • Interface: (2) Thunderbolt
  • Disk Drives: Type – 2x SATA III
  • RPM – 7200
  • Cache – Up to 32MB per drive (64MB on 6TB and 8TB units)
  • Cooling System: Thermo-regulated, quiet smart fan
  • RAID Controller: Hardware RAID 0
  • Size (LxWxH): 9.25" x 5.125" x 3.374"
  • System Requirements: Mac OSX 10.6 or higher
  • Supports multi-stream HDV, DVCPro HD, XDCAM HD, ProRes 422 and uncompressed SD workows

Design and Build

The Hitachi G-RAID is constructed of thick metal alloy with a long footprint for maximum stability on a desk surface. The inside chassis is also metal, with perforations for optimal airflow, bringing in air from the front and sides and exhausting it out the rear through a small 40mm fan. In terms of dual-drive enclosures, the Hitachi G-RAID is easily one of the strongest and most durable design we have encountered... it can easily support being stood on without any concern for damage to the case or drives inside. Hitachi has a blend of sleek design and rugged build quality that few can match.

The overall design is very simple from a connectivity standpoint, with power and two Thunderbolt connections on the rear. This allows users to daisy-chain multiple storage units and taking full advantage of the Thunderbolt's connection bandwidth. The 40mm fan on the rear is partially audible when in use, although not too noticeable if the unit spaced slightly from where you are sitting at your desk.

The inside layout of the Hitachi G-RAID with Thunderbolt is very efficient, leaving room for airflow without being excessibly large. The cable layout keeps airflow restrictions to a minimum with tightly bundled cables, and both drives have airflow clearance on all sides of the drive for maximum heat dissipation. This keeps the 7200RPM Hitachi Ultrastar 7K4000 hard drives inside operating reliably for years to come.

Synthetic Benchmarks

We tested the Hitachi G-RAID with Thunderbolt configured with a software RAID0 array using our Apple Mac Mini testing platform. Using a variety of benchmarks including Xbench, BlackMagic Disk Speed Test, and AJA System Test, we measured the transfer speeds to and from the Hitachi G-RAID.

In Xbench, we measured 256k block sequential write speeds of 240.66MB/s and read speeds of 308.85MB/s. Using the BlackMagic Disk Speed Test, we measured performance of 304MB/s write and 307MB/s read. Lastly, we used AJA System Test with a 16GB file size and recorded a write speed of 308.8MB/s and a read speed of 313.3MB/s.


There's a reason why Hitachi's G-Technology line of external hard drives have built a glowing reputation in the content creation space. They're build extremenly well, look great and are the epitomy of reliability. We found the all-metal enclosure to be incredibly durable and offered plenty fo cooling for the 8TB of storage stuffed inside. With the new G-RAID with Thunderbolt, professionals finally get access to a Mac-friendly, high throughput interface, along with the maximum capacity available for a two bay enclosure.

Performance in RAID0 from a single G-RAID unit measured in excess of 300MB/s across most benchmarks. While very fast for platter-based drives, this is still well below the limit of Thunderbolt, meaning you can easily double or triple those speeds by daisy chaining additional enclosures together. Of course Hitachi G-Tech users are used to such things, as they tend to be more demanding than the average desktop storage user. 


  • Excellent design and enclosure durability
  • Over 300MB/s speeds in RAID0
  • Smart passive and activie cooling design


  •  Heavy compared to other dual-drive enclosures

Bottom Line

For users looking to add fast and dependable storage (that looks good too) to their Thunderbolt-enabled environment, the Hitachi G-RAID with Thunderbolt offers maximum hard drive throughput with up to 8TB of capacity.

Product Page

Hitachi G-RAID at

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