A lot of attention has been paid to high-speed I/O interfaces for computing systems over the last five years. Flash-based storage media capable of multi-Gbps throughput have become very affordable. Display resolutions have also seen a rapid rate of increase. The necessity to support multiple such devices in both consumer and professional computing solutions have exposed the limitations of the traditional external I/O interfaces. While USB 3.x has become successful as an interface for high-speed peripherals, it does not handle display output. Intel has been attempting to solve this problem with Thunderbolt Technology since 2011. Unfortunately, the uptake outside the Apple ecosystem for the first two versions has been minimal at best. Thunderbolt 3, however, promises to be a game-changer. Systems and motherboards with Thunderbolt 3 support started shipping in late 2015. The first Thunderbolt 3 peripheral to appear in the market was the Akitio Thunder3 Duo Pro, a hardware RAID solution with two drive slots. This review looks at the various features of Thunderbolt 3 and what the Akitio Thunder3 Duo Pro brings to the table.

Introduction and Setup Impressions

Direct Attached Storage (DAS) units have been the go-to devices for consumers looking to store and have fast access to large amounts of data. The advent of high-speed interfaces such as USB 3.x and Thunderbolt have enabled a new generation of DAS units that allow the host system to access the member disks without any bottlenecks. We have looked at a few DAS solutions with Thunderbolt 2 before. Today, we are reviewing the first storage solution with Thunderbolt 3, the Akitio Thunder3 Duo Pro. The unit has daisy chaining support (i.e, two Thunderbolt 3 ports), a USB 3.1 Gen 1 device interface and a full-sized DisplayPort 1.2 output that is driven by the DisplayPort lanes in the Thunderbolt 3 link.

The Akitio Thunder3 Duo Pro is meant for desktop use and needs an external 90W power adapter (12V @ 7.5A). The chassis design also allows for stacking, if needed. In addition to the main unit and the power adapter / cord, the package also includes a Thunderbolt 3 cable (capable of 40Gbps data transfer) and a USB 3.1 Gen 1 Type-B male to Type-A cable. A cable-tie, quick setup guide, warranty terms and a reminder to update to the latest drivers / firmware for the host PC are also included. The detailed specifications of the unit are provided in the table below.

Akitio Thunder3 Duo Pro Specifications
Internal Storage Media 2x 2.5" / 3.5" Drives
Interface 2x Thunderbolt 3 + 1x USB 3.1 Gen 1
RAID Modes RAID 0 / RAID 1 / JBOD / SPAN - Hardware Selection Dial
Cooling Aluminium Chassis + Fan
Power Supply 100-240V AC Switching Adapter (12V @ 7.5A DC)
Dimensions 23.8cm x 14.3cm x 9.4cm
Product Page Akitio Thunder3 Duo Pro
Price $378

The gallery below takes us around the aluminum chassis. Important aspects to note include indicator LEDs for the two drives in the front panel and the perforations (which have a filter on the inside) that allow air to be pulled into the unit, over the drives and out through the fan. The rear panel is flanked on either side by screws that can be removed without the need for any tools. Loosening them allows for the external chassis to slide out.
The rear panel has a fan and a switch to control it (can be turned off for SSDs). Two Thunderbolt 3 ports, a full-sized DisplayPort 1.2 output, a power input jack and a USB 3.1 Gen 1 Type-B female port make up the lower part of the rear panel. A Kensington lock slot and the RAID-level selection indicator form the rest of the features.

The RAID-level selection indicator is covered by a plastic film from the inside that makes it impossible to accidentally change the RAID level without opening up the unit.  The gallery below shows the internal components of the Akitio Thunder3 Duo Pro.

On the board side of things, we have the Intel Alpine Ridge Thunderbolt 3 controller in its dual-port form (). The ASMedia ASM1153E fulfills the SATA to USB bridge functionality for the USB 3.1 Gen 1 device port. On the SATA backplane, we have the ASMedia ASM1062R SATA RAID controller that bridges 2x SATA III ports to two lanes of PCIe 2.0. The backplane also has an ASMedia ASM1456 signal switch to mux / demux SATA signals.

The setup process is simple, since the Thunder3 Duo Pro involves hardware RAID. Installing the SSDs or HDDs is a simple tool-less affair. Removal is a bit complicated, since the drives have to be gently tugged out from the SATA connector. A flat screwdriver can be used to set the desired RAID level (RAID0, RAID1, JBOD or SPAN). In case of a live switch of RAID level (i.e, change while the unit is powered on, it is necessary to press the 'Set RAID' button that is visible in the rear panel once the chassis has been slid off. Otherwise, one just needs to set the pointer to the desired RAID level and boot up the unit.

In the rest of the review, we first take a look at Thunderbolt 3 in detail, followed by a description of how our testbed was built and details of our evaluation methodology for the unit. We then talk about the various standard performance benchmarks. Following that, some special Thunderbolt-only aspects such as daisy chaining and its performance implications are discussed.

The Nuts and Bolts of Thunderbolt 3


View All Comments

  • ganeshts - Saturday, April 16, 2016 - link

    I would have agreed with you a year or so back, but the good thing here is that Thunderbolt has emerged successfully out of the Mac shadow. At present, every Thunderbolt 3 device out there is compatible with Windows only, and not Mac.

    From a system perspective, for a very little premium, board vendors can integrate USB 3.1 Gen 2 + Thunderbolt 3 into their notebooks and consumers can get more out of that integrated port compared to a pure USB 3.1 Gen 2 Type-C port. Whether that extra premium is worth it, the consumer should figure out. The board we used - GIGABYTE Z170 board with Alpine Ridge integrated - can be purchased for less than $200. I think at this price, compared to a vanilla system, consumers might be OK with something a bit more future-proof.

    From a device perspective, yes, lots of Thunderbolt peripherals are overpriced. But, eGFX solutions will definitely be attractive to a lot of gaming folks who are looking for portability. Then, there is Thunderbolt networking which is attractive for small workgroups (more of a business use-case there). Daisy chaining is another great feature for thin systems.

    Frankly, a year or two back, I wouldn't have been bullish on Thunderbolt, and would have equated it with Firewire. But, with Thunderbolt 3, I think Intel has finally converged on to the right type of solution.
  • theduckofdeath - Saturday, April 16, 2016 - link

    Mobile gaming with an external GPU will stay a niche, as the bottleneck will still be the poorly cooled mobile technology within the notebook. Especially with DX12 and the likes, processor and motherboard component performance will be a lot more relevant than it has been since Microsoft introduced the hardware extraction layer to Windows last decade.
    And it's not just "some" TB accessories that are overpriced for what you get. Like the previous commenter said, you can build an actual PC for the price of this external case. Use it for storage if you like, or whatever else you'd want to use a spare PC for.
  • bobj3832 - Saturday, April 23, 2016 - link

    I've worked in small offices with 6 people and huge corporations with over 100,000 employees. In every company we always had file servers on the network. Virtually no one kept data locally (except travelling sales people) If your workstation goes down just log in somewhere else and continue working.

    For my personal stuff at home I have a 10 gigabit network. The SATA interface (even for the SSDs I have in the file server) is the bottleneck.

    I just don't have any need for Thunderbolt with a 10G network.
  • bobj3832 - Saturday, April 23, 2016 - link

    And before someone complains of the cost I got used SFP+ cards for $20 each and a switch with 4 SFP+ ports for $520. It also has 24 1G ports. Reply
  • JHBoricua - Saturday, April 23, 2016 - link

    Umm, and I had to log to the site to point how your comment on software raid was even more silly.
    What happens if the machine running a software RAID dies, you ask? Simple. Since it is software RAID, you simply mount the RAID volume on another PC running the same Os. That's the beauty of software RAID, it is not tied to the hardware.

    Let me ask you this. What happens when the failed device happens to be this enclosure with its 'hardware' RAID? Well, you better have a spare one of the same make/model lying around or you won't be able to recover the data. But hey, you'll probably be able to use the same cable.

    Seriously, did you even pause to think before commenting on the merits of software RAID vs this device?
  • damianrobertjones - Thursday, April 14, 2016 - link

    I recall, all those years ago, that USB was supposed to feature daisy chaining. Reply
  • HideOut - Thursday, April 14, 2016 - link

    Never. But I think firewire was. USB has always been hub + spoke layout. FW could chain I think. Reply
  • DanNeely - Thursday, April 14, 2016 - link

    You could fake daisy chaining in USB by connecting hubs to each other; and in theory there was no reason you couldn't make a device with a 2port hub that used 1 port internally and exposed the 2nd for daisy chain type usage. Aside from a few higher end keyboards I've never seen anything like this done.

    FW had direct proper support for daisy chaining; but neither of the FW HDD enclosures I owned supported it.
  • hrrmph - Friday, April 15, 2016 - link

    That's how most high-port-quantity USB hubs do it. They internally daisy chain. A "normal" USB hub is typically 4-ports. Use the last of those 4 ports to daisy chain to 4 more ports. The user sees a physical 7 ports on the outside of the hub. Reply
  • Vidmo - Thursday, April 14, 2016 - link

    Waiting on the eight drive version to replace my current USB 3.0 local DAS backup solution. Backing up 36TB of data takes a long time over USB 3.0. Reply

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