by Kevin OBrien

Seagate GoFlex Thunderbolt Adapter Review

Seagate's claim to fame when it comes to both their GoFlex desktop hard drive line and the GoFlex portable hard drive line are the adapters that allow the user to swap between interfaces. Seagate has long supported USB, USB 3.0 and FireWire options, but at CES they announced a new Thunderbolt option. This gives Mac users for now, speedy access to external storage that in some cases, like the MacBook Air, wasn't available before. The Seagate GoFlex Thunderbolt Adapter is compatible with the entire GoFlex portable hard drive line including the GoFlex Satellite

The adapter comes with a 90-day warranty and users will have to provide their own Thunderbolt cable, which is standard with Thunderbolt storage solutions. The adapter is trickling into retail now, with a suggested retail price of $99.99.

Seagate GoFlex Thunderbolt Adapter Specs

  • Model - STAE121
  • Dimensions - 4.83" x 3.08" x 1.09"
  • Weight - .21 pounds
  • Bus powered
  • Compatible with all portable GoFlex drives


The Thunderbolt adapter is actually quite large when you compare it to any of the other Seagate GoFlex adapters. With the USB 3.0 adapter coming standard on our 1TB FreeAgent GoFlex external hard drive, we used it in our side by side comparison. The difference is night and day to say the least.

The bulk comes from the Thunderbolt interface, which on a larger drive you might not mind the added heft. On a portable solution centered around a 2.5-inch hard drive though the extra size is near the volume of the drive itself. Add in the one size fits all $50 Thunderbolt cable from Apple which is also rather oversized for portable applications and you can kind of see your travel baggage requirements increasing. For some notebooks such as the Apple MacBook Air, where the two choices are either USB 2.0 or Thunderbolt, this is your only option for a faster connection.

One side note for those interested in buying the GoFlex Thunderbolt adapter for other uses, it is compatible with any standard 2.5-inch hard drive and SSD. The mounting is a bit crude since it has nothing to connect to besides the SATA power and data port, but it does work, and appears to the the cheapest, if not only DIY Thunderbolt solution on the market.


Thunderbolt makes heady performance claims. With a 10Gb/s throughput potential, it's 20 times faster than USB 2.0 and 12 times faster than FireWire 800. Of course we know these upward limits are theoretical and the device connected has a great deal to do with overall performance. That's evident in this case, as the hard drive inside the GoFlex Satellite, isn't exactly the ideal candidate to show what Thunderbolt is capable of, but still accurate to show that for existing products the performance increases might be underwhelming for some.

To see just how Thunderbolt stacks up with the GoFlex product line, we used a 1TB FreeAgent GoFlex portable hard drive, which came with USB 3.0 originally. To show the performance spread, we included IOMeter sequential large-block benchmarks for a wide range of interface options, including USB 2.0, USB 3.0, Thunderbolt, and native SATA to the hard drive itself.

Over a USB 2.0 connection, which by this point in its life could be considered a universal standard across all platforms, we measured transfer speeds of 33MB/s read and 28.4MB/s write. Stepping up to USB 3.0, those speeds increased to 80.5MB/s read and 80.4MB/s write. Over Thunderbolt, those speeds measured to 80.6MB/s read and 80.4MB/s write. For this particular drive, the limiting factor for both USB 3.0 and Thunderbolt was the drive itself... not the interface. Connecting to the drive over its native SATA 3.0Gb/s we found transfer speeds to hit the same upper-limit of 80.5MB/s read and 80.4MB/s write.


Thunderbolt is tricky, while it offers tremendous speed potential, the number of use cases that can justify the expense of the hardware and $50 cable are a bit thin. That said, there are many who will pay up for Thunderbolt, which as we see here can provide substantially improved performance for computers who are port constrained, like the MacBook Air. There are of course other early adopters and the like who have Thunderbolt ports and cables and don't mind paying the $100 for the Seagate Thunderbolt sled to gain access to the external drive's full speed. Those users however might be more interested in the Thunderbolt sled for its universal SATA interface, meaning any 2.5" notebook drive can be used with it. 

We saw speeds increase from around 30MB/s over USB 2.0 to 80MB/s over Thunderbolt with the Seagate GoFlex portable external hard drive. The down side though is USB 3.0 could also offer the same speed, with less bulk and much less cost for systems with a wider range of port options. With the upper speeds of 2.5-inch hard drives barely pushing the limit of USB 3.0 (or FireWire 800) users won't find this adapter really useful until more SSD solutions come to market, since the fastest 2.5-inch GoFlex product Seagate currently sells only incorporates a 7200RPM notebook hard drive.


  • Compatible with entire GoFlex portable line
  • Well built
  • Simple to use


  • No performance gain over USB 3 when used with GoFlex portable hard drives
  • Expensive for most users

Bottom Line

Seagate's Thunderbolt adapter for their line of GoFlex portable hard drives does its intended job well, but it's hard for most, outside of MacBook Air owners, to justify the expense given USB 3.0, FireWire 800 and Thunderbolt performance is about the same - all limited by the hard drive. 

Seagate GoFlex Thunderbolt Adapter (STAE121)

See how the Thunderbolt Adapter does when paired with an SSD

Discuss This Review