Netstor NA611TB3 Thunderbolt 3 NVMe External SSD Review

We've tested several very fast external drives this year, but none are as fast as Netstor’s NA611TB3. This product is slightly different, though, because it doesn't actually come with storage media. For roughly $300 you get a Thunderbolt 3 enclosure that you can arm with two high-performance NVMe SSDs that will rip through any workload.

"Small yet stunningly fast" is Netstor's tagline for the NA611TB3. On the surface, the product is an external drive enclosure with a name only a mother could love. In practice, the enclosure is the fastest external storage product we've ever tested. You can have one, too, but there are a few serious drawbacks. You have to piece the storage together, which adds to the price tag. This is one device that is truly only as fast as you can afford to make it.

Netstor designed the device to take full advantage of the performance potential of the Thunderbolt 3 interface. The Thunderbolt 40Gbps specification is misleading and often misunderstood. The bridge chip connects to your PCI Express bus with four PCIe lanes at 32Gbps, which is the same bandwidth available to an M.2 socket. The extra 8Gbps of throughput comes from the video signal that flows from a different feed, which is usually a video card.

The enclosure features two PCI Express x2 lanes per SSD to help maximize bandwidth. The dual ports also allow for two separate volumes or a RAID array, which you build with the operating system's software tools. Enthusiasts may gravitate towards RAID 0, but Netstor designed this enclosure for serious professional users that might prefer the redundancy of RAID 1 or two separate volumes.

As we've seen countless times in our SSD reviews, mixed workloads can reduce overall storage performance by as much as 95%. To avoid the performance penalty associated with mixed workloads, many professionals will read data from one storage device and write the final product back to another. For many of us, SATA has been the dominant storage interface for several years, but it is only a half-duplex interface. That means it can only read or write data serially–it can't do both at once. The NVMe interface is full-duplex, but affordable NVMe SSDs still face challenges from the reduced number of NAND die and the limited number of controller channels. Using two devices for dedicated tasks sidesteps those problems.


*40Gbps Interface Speed (32Gbps Data)

The Netstor NA611TB3 is surprisingly simple, which is just the way we like it. The enclosure has an external Thunderbolt 3 connection. Inside the enclosure, there are two M.2 M-Key slots with a PCIe 3.0 x2 connection assigned to each. It would have been possible to use a single PCIe 3.0 x4 connection to a single storage device, but a single SSD cannot take full advantage of the interface at low queue depths. By splitting the available bandwidth between two devices, users can push more data through the system at more realistic queue depths.

We aren't real fond of the external power brick. The Thunderbolt 3 specification allows some devices to push up to 100 watts (20A at 5V). In a perfect world, every host system would follow the specification. In reality, several other specifications make Thunderbolt 3, and the cables used, an alphabet soup of standards. Many implementations would not provide enough power for two high-performance NVMe SSDs, so Netstor built the system with an external power brick to overcome the confusion.


  • 40 Gbps transfer speeds via Thunderbolt 3
  • Pocket-sized storage capable of 4K video editing
  • Two M.2 sockets
  • Variable speed fan
  • Up to 3x faster than USB 3.1 Gen2
  • Capable of daisy chaining up to 5 devices

Pricing & Warranty

We only found the Netstor Thunderbolt 3 NA611TB3 at one US retailer. lists the MSRP at $360, but the drive is on sale for $339. You still have to add at least one M.2 SSD designed for PCI Express. Most PCIe SSDs are NVMe, but some older AHCI-based products are floating around, like the early Samsung SM951. The enclosure comes with a two-year manufacturer warranty.

Accessories & Software

We found an assortment of accessories inside the box. The Thunderbolt 3 cable is the most important. Not all Thunderbolt devices come with a cable, so this was a nice addition. Early Thunderbolt and Thunderbolt 2 cables were expensive, but the new specification utilizes commodity USB-C connectors and allows for shorter cables that are passive.

Netstor also includes the power brick. It uses a standard PC power connector, which makes it easy to move from one host system to another.


Netstor has an image of the enclosure on the front of the package. We found a breakdown of the specifications on the rear of the package.

A Closer Look

The system has a retro-looking chrome-style button and three status LEDs on the front. There are vents on the upper and lower edges of the front panel. The rubber non-skid cover overlaps the panel slightly.

The connections are on the back. Two Thunderbolt 3 connections allow the enclosure to fit in the middle of a chain of devices. A small switch adjusts the fan speed. We found the low setting to be completely silent, and the high-speed option is not noticeable from just a few feet away. The pitch of the fan is not a high frequency whine like you might expect from such as a small fan.


Netstor doesn't currently offer a loaded drive. You will have to remove the two screws on the back panel and dive in with some manual labor. Ideally, these would be the only screws that provide access to the M.2 slots, but that's not the case. There's also a large aluminum shield that you need to remove to install the drives. This is actually a good thing because the plate doubles as large heatsink that pulls heat from the drives. With this much surface area, it would be very difficult to push the drives into a thermal throttle condition.


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