Earlier this year we had the opportunity to review the Seagate
GoFlex Thunderbolt adapter designed for Seagate's portable hard drive range. Seagate has since released the
GoFlex Desk Thunderbolt adapter which can be used to upgrade its USB 2.0 and USB 3.0 desktop GoFlex drives. The concept is a good one - pay a little more for the Seagate GoFlex drive upfront, but you then have the flexibility to upgrade to a faster I/O as the technology becomes available. So is it worth upgrading your USB drive to Thunderbolt and is it worth the $190 price of admission?
Some background on the Thunderbolt I/O:
If you are not familiar with Thunderbolt, it is a new I/O standard developed by Intel with input from Apple. Thunderbolt is capable of transferring data at up to 10Gbps, which is double the bandwidth of USB 3.0 at 5Gbps. Firewire 800 is capable of a maximum transfer rate of 800Mbps with USB 2.0 coming in at around 480Mbps peak, but can deliver an effective throughput of 35MBps. Although Apple hardware has been fitted with Thunderbolt I/O technology since last year, it has not been widely adopted to date, largely because of the additional cost of the ports coupled with the relatively high price of Thunderbolt peripherals.
We recently reviewed Apple's
next-generation MacBook Pro with Retina display, which includes just not one, but two Thunderbolt ports. Apple has also now added Thunderbolt ports to the MacBook Air line-up as well making it even more likely that there will be another wave of users keen to maximize the potential of their hardware setups. If you already own a Seagate GoFlex desktop hard drive, the temptation to add the Thunderbolt adapter will be high. If you have a Seagate USB 2.0 drive, the USB 3.0 adapter is going to set you back as little as $20. Surely the $170 price difference between the USB 3.0 adapter and the Thunderbolt adapter must be worth it?
A matter of bandwidth:
Seagate advertises the Thunderbolt adapter as being up to 20x faster than a USB 2.0 connection. In practice, the reality is much different. Seagate uses a clever swap system that relies on the SATA II connection, making it very easy for users to swap the I/O. SATA II can transfer data at a maximum of 3Gbps, so already, the savvy reader will realize that a drive using a SATA II adapter is not going to get anywhere near the maximum bandwidth of a Thunderbolt connection. Further, the theoretical bandwidth of USB 3.0 peaks at 5Gbps.
To confuse matters further, a spinning hard drive also has limitations on how quickly it can read and write data. This will also vary among hard drives depending on their revolutions, be it 7,200rpm or 5,400rpm. Further, depending on the technology used by the manufacturer, a spinning hard drive can reach maximum read/write speeds of anywhere between 50 to 150MBps. At this point, it starts to become pretty clear that having a Thunderbolt connection isn't going to do anything to improve this inherent limitation.
The flexibility of Thunderbolt:
But there is one more aspect of Thunderbolt technology to consider before you might write it off in this context. If you have a look at the photos, you will see that Seagate has included two Thunderbolt ports on the rear of its new GoFlex Desk adapter. It is what makes the technology so cool. Obviously one port will need to be connected to your computer, while the other can then be used to connect the device to a Thunderbolt display or up to five other Thunderbolt equipped hard drives or other peripherals. Belkin is due to release a Thunderbolt dock later this year connects a mix of USB 3.0, USB 2.0, Firewire and Ethernet devices over the one Thunderbolt connection. Apple's Thunderbolt display also acts as a dock in this way.
The numbers, how do they stack up?
To run our numbers, we used the Black Magic Design Disk Speed Test (Free,
Mac App Store). Before we tested the various adapters and connections, we ran the test on our MacBook Pro with Retina display. Unsurprisingly, with its ultra fast flash architecture, the internal drive on the next-gen MacBook Pro returned a typical write speed of just over 400MBps and read speeds over 440MBps. The flash storage is connected to the Mac using a SATA II connection enabled at 6Gbps.
By comparison, a Western Digital portable hard drive using a USB 2.0 connection achieves a typical write speed of around 33MBps and a read speed of around 37MBps.
Given these speeds, it suggests that the portable hard drive is likely using a disk spinning at 5,400rpm. Switching to a USB 3.0 connection using the latest Seagate desktop hard drive we achieved a typical write speed of around 106MBps with a write speed around 106MBps as well.
Swapping out the USB 3.0 adapter on the hard drive to Thunderbolt yielded typical write speeds around 126MBps and typical read speeds of 126MBps.
Final thoughts:
So based on this result, there is approximately a 15 to 20 percent performance advantage to be had by opting to upgrade your GoFlex desktop hard drive to Thunderbolt. For video professionals and users looking for the fastest performance, even with a traditional spinning hard drive, Thunderbolt will give you the best performance. It will also give you the most flexibility, given the second Thunderbolt port included in the adapter. In terms of value versus performance, USB 3.0 will get the job done pretty well for most users.
The only way that both USB 3.0 hard drives and Thunderbolt hard drives will get any faster, is if users opt for even more expensive SSD options, which are starting to hit the market. However, these will have much more limited storage by comparison and could only seriously be considered by pros. If you are serious about the speed of your connection, you might also consider adding a naked SSD to the SATA II connection on either the Seagate GoFlex Desk adapter or the GoFlex adapter for portable drives. An SSD could boost your write speeds to at least 260MBps, and give you read speeds as high as 500MBps.
If you have got the money, the flexibility and additional speed of the Thunderbolt adapter could still make it attractive, despite the steeper price of admission. A lot of this can be put down to the need for additional chips and circuitry required to make the standard possible - even Thunderbolt cables have a small chip in them, which is why they are comparatively so expensive. In day to day use, the difference between USB 3.0 and Thunderbolt is noticeable. We store our iTunes collection on our external hard drive. It is painfully slow to load up over USB 2.0, much better over USB 3.0, and almost instantaneous over Thunderbolt. Whether that is worth the additional price of admission will be decided by your hardware and the depth of your wallet.
By
Sanjiv Sathiah
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