The Bottom Line
We don't usually see DAS units come through from TerraMaster, opting for NAS solutions out of personal preference. That said, this two-bay DIY solution was intriguing enough based on the price that I decided to give it a go.
The D2 is the two-bay variant in this lineup with both 5 and 8 bay solutions waiting in the wings for those needing more capacity. The D2 features a portable design offering two 40Gbps capable Thunderbolt 3 ports with daisy chaining abilities up to 6 devices.
Additionally, we have charging capabilities up to 15 watts for macOS devices and hardware RAID support for 0,1 and JBOD. The D2 does breakout its Thunderbolt interface to DisplayPort as well, allowing consumers to connect additional displays with support for 4K.
Performance is rated at 760 MB/s for the two-bay D2 using SSHD's but IronWolf and WD Red are the recommended drives. Compatibility includes both Windows and macOS machines. MSRP of the D2 Thunderbolt 3 comes in at $249.99 with a one-year warranty.

The D2 shares the almost purple colorway of past TerraMaster products, with a sticker on the side offering model info.


Today | 7 days ago | 30 days ago | ||
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$259.99 USD | - | |||
$329.99 CAD | - | |||
£269.37 | - | |||
$259.99 USD | - | |||
* Prices last scanned on 2/11/2025 at 12:12 am CST - prices may not be accurate, click links above for the latest price. We may earn an affiliate commission from any sales.
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Unboxing, we get right to it with the enclosure: a full aluminum shell plastic front and back panels. To the left, we have the power button and LEDs for activity.

On the backside, we have power at the top, followed by DP and two Thunderbolt 3. At the very bottom, we have the RAID mode switch.

The drive trays are plastic using mounting holes on the bottom only.

Included in the box, we have the power adapter and drive screws.

For my testing, we used two Seagate 600 Pro SSDs. At Q32, we see 822 MB/s read and 477 MB/s write in RAID 0

Sticking with RAID 1, performance looks quite stable in ATTO peak starting at 64K holding 780 MB/s read and 465 MB/s write.

On to RAID 1, we see only a slight dip in write performance down to 242 MB/s with read sticking to 825 MB/s.

The sweet spot has shifted slightly for RAID 1, moving down to 256K through 64M holding 780 MB/s read and 233 MB/s write.
With low-cost appliances comes a few corners cut, and with the D2, I can say while most of the enclosure is right solid, the drive trays have issues sliding into the chassis, and the front and rear panels look and feel like lower-cost plastics were used. Functionality is excellent if you have used DIP switches in the past; if not, there is a small learning curve.
The performance was a touch over what I was expecting from a two-bay unit and marketing for that matter. At 825 MB/s, we don't quite get the full performance out of both of our 600 Pro SSDs, but there is plenty of room for two high capacity drives to stretch their legs.
I would like to see TerraMaster move the D2, D5, and D8 into a software platform in the future. It's a bit odd to have Thunderbolt 3 technology paired with such an old hardwired way of switching RAID modes.
Price is a substantial feature of the D2; to begin with, we don't see many two-bay Thunderbolt 3 solutions in the DIY space, and at $249.99 MSRP, it's certainly worth looking at.
Tyler's Test System Specifications
- Motherboard: ASUS Crosshair VIII Formula X570 (buy from Amazon)
- CPU: AMD Ryzen 5 3600 (buy from Amazon)
- RAM: Corsair Vengeance 16GB 2x8GB DDR4 3600 (buy from Amazon)
- Cooler: Corsair Hydro H60 (buy from Amazon)
- Case: Corsair Carbide 275R (buy from Amazon)
- OS Storage: Corsair MP600 1TB (buy from Amazon)
- Power Supply: Corsair RM850x (buy from Amazon)
- OS: Microsoft Windows 10 (buy from Amazon)