G-Technology G-DOCK ev: Thunderbolt and two removable drives for ultimate flexibility

G-Technology's new G-DOCK ev ($749.95 with two 1 TB G-DRIVEs) is a different animal. Think of having two removable, portable USB 3.0 drives that you can take into the field with you, and then being able to plug those drives into a Thunderbolt dock for high(er) speed transfer of data when you're back in the office or studio, and you've figured out the idea of this device. Unfortunately, the concept and reality of the G-DOCK ev are two separate things.

The G-DOCK itself isn't exactly portable, measuring 7.87" x 5.12" x 3.54" and weighing 4 pounds, 5 ounces. The removable drives, however, are little self-contained units that are perfect for popping into the pocket of a jacket or a computer bag. The G-DRIVE ev USB 3.0 drives are quite a bit more compact, measuring just 5.14" x 3.29" x .65" each and tipping the scales at 10.2 ounces each. Those drives have a USB 3.0 port on the back of them for use in the field, as well as a SATA port covered by a small removable (and easily lost) plastic door. To use the drive in the G-DOCK, you remove the door and then slide the drive in until it locks. To remove the drive(s), there are two large buttons on the front of the device next to the drives.

It should be noted that you don't just push the button to safely eject the drives, something that isn't immediately obvious. One would hope that G-Technology would have figured out a way to safely dismount the G-DRIVE ev drives automatically with a push of the button; instead, you need to be sure to drag the drive icons to the OS X trash to dismount them first. Likewise, G-Technology doesn't include any utilities for setting up the two G-DRIVEs as a RAID pair, instead pointing users in the direction of Apple's OS X Disk Utility.

The G-DOCK can be set up as two individual drives or as one RAID 0 or RAID 1 array. For the purposes of testing, I used it as two individual drives for initial testing and then set it up as a RAID 0 (a stripe set of two 1 TB drives) for the final benchmark.


Benchmarking of the G-Technology G-DRIVEs and G-DOCK ev was done with Intech Software's SpeedTools QuickBench 4.0 software. To ensure accuracy in testing, I performed a 100-cycle complete test. This subjects the drive to sequential and random read and write tests with file sizes from 4K to 100 MB, then graphically or textually displays that information to show the "sweet spots" for a specific drive or array. For example, if your work involves shuffling around a lot of very large files, you'll probably want a drive that has peak read/write speeds for files around your average file size.

I first tested an individual G-DRIVE connected via USB 3.0. The standard tests (first four results) use nine different file sizes between 4 KB and 1024 KB. The large tests use transfer sizes between 2 and 10 MB, while the extended tests look at file sizes between 20 and 100 MB. These test results were not compared to any other devices, as TUAW has not recently tested any non-RAID devices with the QuickBench software.

  • Sequential Read: 110.628 MB/Sec

  • Sequential Write: 113.286 MB/Sec

  • Random Read: 21.857 MB/Sec

  • Random Write: 28.756 MB/Sec

  • Large Read: 131.540 MB/Sec

  • Large Write: 125.343 MB/Sec

  • Extended Read: 135.542 MB/Sec

  • Extended Write: 135.014 MB/Sec

Next, I performed the tests on a G-DRIVE in the G-DOCK ev through a Thunderbolt connection:

  • Sequential Read: 117.730 MB/Sec

  • Sequential Write: 120.449 MB/Sec

  • Random Read: 22.769 MB/Sec

  • Random Write: 28.896 MB/Sec

  • Large Read: 134.485 MB/Sec

  • Large Write: 130.679 MB/Sec

  • Extended Read: 135.313 MB/Sec

  • Extended Write: 134.928 MB/Sec

I found it odd that the differences in speed between USB 3.0 and Thunderbolt connections were negligible. Next, the two G-DRIVEs in the G-DOCK ev were set up as a RAID 0 volume approximately 2 TB in size, and benchmarks were run using a Thunderbolt connection:

  • Sequential Read: 189.675 MB/Sec (140.504 MB/Sec for Drobo 5D)

  • Sequential Write: 197.831 MB/Sec (93.245 MB/Sec for Drobo 5D)

  • Random Read: 22.432 MB/Sec (116.435 MB/Sec for Drobo 5D)

  • Random Write: 38.360 MB/Sec (70.410 MB/Sec for Drobo 5D)

  • Large Read: 272.062 MB/Sec (341.327 MB/Sec for Drobo 5D)

  • Large Write: 262.744 MB/Sec (282.060 MB/Sec for Drobo 5D)

  • Extended Read: 266.927 MB/Sec (255.953 MB/Sec for Drobo 5D)

  • Extended Write: 264.170 MB/Sec (262.864 MB/Sec for Drobo 5D)

The RAID 0 benchmarks showed some interesting results. Random Read/Write of smaller-sized files was surprisingly slow, while the G-DOCK ev performed admirably when reading and writing larger files. This indicates that the RAID configuration would work well for use cases involving large file sizes. It should be noted, though, that once you create a RAID array (either mirrored or striped) with the two G-DRIVEs, you can no longer pop them out for portable use. Essentially, you need to decide ahead of time whether you want a pair of portable drives that you can pop out of a Thunderbolt dock or a Thunderbolt RAID 0 or RAID 1 array.

That's why I think the G-DOCK ev is kind of an odd duck. For portable Thunderbolt drives, it's possible to get two 1 TB drives for about $300 -- much less expensive than the G-DOCK ev with its two 1 TB removable drives. If you're looking for Thunderbolt RAID setups, you can buy one of G-Technology's own 8 TB G-RAID arrays for about the same price as the 2 TB RAID 0 (or 1 TB RAID 1) G-DOCK ev -- but of course you lose the portability.


The G-Technology G-DOCK ev provides fast read/write of large files as a Thunderbolt RAID array and the removable USB 3.0 G-DRIVEs are reasonably fast as well. However, most users would be better served by selecting their most common use case -- need for large RAID storage or need for portability -- and purchasing a single solution that fits that need. The users would save money and most likely gain capacity over this odd "portable / RAID" hybrid solution.


  • Excellent construction, sturdy devices made of aluminum

  • Relatively fast performer when reading and writing large files, although no faster than competing devices


  • Expensive compared to dedicated RAID arrays or separate portable drives

  • Doors for removable drives are small and would be easy to lose

  • No speed advantage of putting the removable USB 3.0 drives into the Thunderbolt dock

  • Drives do not perform well with small file sizes

  • Removable drives should dismount automatically when the drive button is pushed; instead, the drives need to be dismounted manually

Who is it for?

  • Due to the cost of the G-DOCK ev, it's relatively common performance, the fact that the removable USB 3.0 G-DRIVEs aren't any faster when placed in the Thunderbolt dock, and the fact that it's really an either/or solution (RAID or portability), we cannot recommend purchasing this product.