TerraMaster D4-320 4-Bay USB 3.2 Gen 2 Enclosure

BH #TED4320 • MFR #D4-320
Print
TerraMaster D4-320 4-Bay USB 3.2 Gen 2 Enclosure
Key Features
  • 4 x 3.5/2.5" SATA Drive Bays
  • 1 x USB-C 3.2 Gen 2 Port
  • Read Speeds of up to 1016 MB/s
  • Write Speeds of up to 960 MB/s
The D4-320 4-Bay USB 3.2 Gen 2 Enclosure from TerraMaster can function as a stand-alone storage enclosure, or be used an expansion enclosure for TerraMaster NAS devices running TOS 5.1 or above. Built with four SATA drive bays that can handle 2.5 or 3.5" hard drives and SSDs, the D4-320 delivers data transfers of up to 1016 MB/s and write speeds of up to 960 MB/s when equipped with four SSDs. It connects to your host Windows, Mac, Linux, or TOS system using a 10 Gb/s USB-C 3.2 Gen 2 (3.1 Gen 2/3.1) port that is compatible with USB 3.2 Gen 1 (USB 3.1 Gen 1/3.0), Thunderbolt 3, or Thunderbolt 4. Please note that the D4-320 may not be configured as a RAID without the use of third-party software.
More Details
In Stock
No Store Display
Free 2-Day Shipping
Protect Your Gear
Add a protection plan from $14.99
Drive Bays
Ask an Expert
800-606-6969

TerraMaster D2-320 Overview

The D4-320 4-Bay USB 3.2 Gen 2 Enclosure from TerraMaster can function as a stand-alone storage enclosure, or be used an expansion enclosure for TerraMaster NAS devices running TOS 5.1 or above. Built with four SATA drive bays that can handle 2.5 or 3.5" hard drives and SSDs, the D4-320 delivers data transfers of up to 1016 MB/s and write speeds of up to 960 MB/s when equipped with four SSDs. It connects to your host Windows, Mac, Linux, or TOS system using a 10 Gb/s USB-C 3.2 Gen 2 (3.1 Gen 2/3.1) port that is compatible with USB 3.2 Gen 1 (USB 3.1 Gen 1/3.0), Thunderbolt 3, or Thunderbolt 4. Please note that the D4-320 may not be configured as a RAID without the use of third-party software.

Each drive bay is hot swappable and allows for tool-free installation. Plug-and-play connectivity means that no additional drivers are required for use, while an intelligent 120mm cooling fan operates based on system temperature, ensuring that the drives operate within their optimal range.

Please note that the D4-320 does not currently support individual drives larger than 30TB.

New Upgrade, Refreshed Experience
As an upgrade to the D4-300, the D4-320 offers several revolutionary changes while maintaining affordability. Its new design concept offers a stylish and minimalist appearance that is more aesthetically pleasing, while its underlying technology offers a qualitative leap in terms of performance, allowing users to access outstanding functionality.
Speed Boost
The D4-320 utilizes the USB 3.2 Gen 2 protocol to achieve a data transfer speeds of up to 10 Gb/s, which is twice the speed of the D4-300, which runs at 5 Gb/s. When equipped with four hard drives, the actual read/write speed can thus be measured at up to 1016 MB/s (combined read/write with four WD Red 8TB SSDs). Even with just one 1TB WD Red SSD installed, the read speed reaches 510 MB/s. Thus, whether using multiple hard drives operating in parallel or ensuring the efficient operation of a single hard drive, the D4-320 demonstrates exceptional performance.
Convenient Swapping of Hard Drives
The hard drive bracket introduced by the D4-320 offers tool-free installation and removal of hard drives, making the whole process simple by eliminating the need for cumbersome tools. In addition, the push-lock design created by TerraMaster allows gentle pressure to be used to ensure a secure lock, effectively preventing detachment or disconnection. This not only ensures stable data transmission, but also enhances the efficiency of hard drive replacement. Installing a hard drive thus takes only a few seconds, providing additional convenience for users who frequently swap hard drives.
Better Heat Dissipation
The D4-320 is equipped with an intelligent, temperature-controlled, low-noise fan. The fan speed is constantly adjusted based on hard drive temperature, ensuring that the hard drives always operate within their optimal temperature range. In addition, the carefully designed internal structure of the device effectively enhances internal air pressure, further reducing the working temperature of the hard drives and significantly minimizing any resonance between the device components and hard drives. Even under a full load, the D4-320 thus maintains excellent low-noise performance, providing a quiet and comfortable working environment.
Reduced Noise: up to 50% Quieter
As desktop products are typically positioned close to users, their noise levels must be subject to strict requirements. During read/write processes using mechanical hard drives, the high-speed rotation of disks and heads can generate excess vibrations and noticeable noise, which may resonate within the product enclosure, further amplifying the overall sound level. To address this, engineers at TerraMaster have not only implemented additional vibration damping measures in this new generation of products, but also have carefully designed numerous specialized sound absorbing panels. The resulting designs help to significantly reduce noise levels. Based on rigorous testing, this generation of products demonstrates a remarkable reduction in noise of up to 50% as compared to the previous generation's products. In standby mode, the noise level dips below 21 dBA, creating an exceptionally quiet use environment.
Storage Expansion
The D4-320 boasts powerful storage expansion capabilities, supporting the installation of up to four hard drives with a maximum individual hard drive capacity of 30TB (compatibility with larger capacity hard drives is yet to be verified). This means that users can achieve massive storage of up to 120TB (4 x 30TB), allowing the D4-320 to meet a wide variety of large-scale storage needs. Importantly, however, the D4-320 itself does not provide RAID functionality, supporting only a single-drive operating mode. If users require a RAID array to enhance data storage performance and security, they must utilize third-party software RAID management tools to achieve this.
Compatible with Various Hard Drives
The D4-320 supports multiple types of hard drives, including 3.5" SATA hard drives, 2.5" SATA hard drives, and 2.5" SATA SSDs.

To ensure the stable operation and optimal performance of the device, it is crucial to select hard drives that are known to be compatible. Incompatible hard drives may result in device disconnection, reduced speeds, or failure to recognize a hard drive. Before making any drive purchases, users are thus strongly advised to refer to TerraMaster's hard drive compatibility list to ensure that the chosen hard drives are a perfect match for the D4-320 to ensure a seamless storage experience.
Strong Interface Compatibility
The D4-320 features a USB-C interface and comes with a 3.3' USB-C to USB-C cable. This design allows the D4-320 to seamlessly connect to various computer interfaces, including USB USB 3.2 Gen 1, USB 3.2 Gen 2, Thunderbolt 3, and Thunderbolt 4. Regardless of the type of interface the computer uses, the D4-320 can thus provide a stable and efficient data transfer experience.
Hot Swap
The D4-320 supports hot swapping. You can replace the hard disk when the device is powered on, making data transfers more convenient.
Driverless, Plug-and-Play
The D4-320 offers true plug-and-play functionality, without requiring the installation of any drivers. It also effortlessly supports various cross-platform operating systems, including Mac, Windows, and Linux. Its full compatibility with USB protocols also allows it to be easily connected to a variety of devices, including computers, TVs, servers, and set-top boxes to offer even greater convenience and flexibility. In any environment, the D4-320 thus allows effortless data storage and sharing.
Expansion of NAS Storage Space
Based on careful adaptation and optimization by the professional team at TerraMaster, the D4-320 offers seamless connection to the USB interface of TerraMaster NAS. Leveraging the powerful TOS system developed by TerraMaster, users can easily create arrays and storage pools on the D4-320, effectively expanding the storage space of their NAS to meet growing demands for data. This feature is only applicable to TerraMaster NAS devices running TOS 5.1 or above. Based on this innovative feature, the D4-320 provides users with a more flexible and diverse storage expansion solution.
Intelligent Disk Sleep
The D4-320 supports work mode management by intelligently entering sleep mode along with the computer system. This design not only effectively reduces the working time of the hard drives, minimizing wear on the hard drive motors, but also extends the lifespan of the hard drives themselves. This maximizes efficient storage while also providing peace of mind in terms of protecting hard drive assets.
Safety
To ensure the safety of the device and hard drives, the D4-320 incorporates an advanced power protection design. In the event of users incorrectly connecting an incompatible power source, the device will immediately activate a built-in protection mechanism, effectively preventing damage to the device and hard drives from excessive currents or unstable voltages. This considerate design offers added peace of mind on using the D4-320, eliminating any concerns about potential losses due to power-related issues.
Automatic Backup
TPC Backupper is a user-friendly Windows backup tool that allows you to schedule the backup of folders and disk partitions on your Windows system to TerraMaster USB devices or NAS network storage servers. To start automatic backups, simply connect the device to your computer, install the TPC Backupper client, and set up a scheduled backup task. This straightforward and reliable backup solution enables you to concentrate on your work, while in the background the TerraMaster D4-320 concentrates on its work to protect your crucial data. TPC Backupper supports both incremental and differential backup strategies and is compatible with Windows 8, 8.1, 10, and 11. It is available via a free download.

TerraMaster D2-320 Specs

Key Specs
RAID
Yes: Supported RAID Modes: 0 / 1 / 5 / 10 / JBOD
Number of Bays
4x 2.5"/3.5" SATA (Unspecified Version)
Inputs/Outputs
1x USB-C 3.1/3.2 Gen 2
Drives
RAID
Yes: Supported RAID Modes: 0 / 1 / 5 / 10 / JBOD
Transfer Rates
1016 MB/s (Read)
960 MB/s (Write)
General
Number of Bays
4x 2.5"/3.5" SATA (Unspecified Version)
Maximum Capacity
With Drives Installed up to 120 TB
Inputs/Outputs
1x USB-C 3.1/3.2 Gen 2
Media Card Slots
No
PCI Expansion
No
Software
OS Compatibility
Windows
macOS
Security
Encryption
No
Security Features
No
Electrical
Input Power
100 to 240 VAC, 50 / 60 Hz
Power Consumption
40.8 W (Typical)
9.8 W (Standby)
PSU
1 x 72 W
Physical
Operating Conditions
32 to 104°F / 0 to 40°C at 5 to 95% Humidity
Storage Conditions
-5 to 140°F / -20 to 60°C
Certifications
CCC, CE, FCC, KC, RoHS
Cooling
1x 120 mm Fan
Noise Level
21 dBA
Dimensions
8.7 x 7 x 6.1" / 222 x 179 x 154 mm
Weight
4.2 lb / 1.9 kg
Packaging Info
Package Weight
6.295 lb
Box Dimensions (LxWxH)
11.1 x 10.8 x 8"

TerraMaster D2-320 Reviews

Terramaster D2-320 is good value

By Octavio
Rated 4 out of 5
Date: 2026-04-21

The unit is being used for longer term storage. Transfer to unit via USB 3.2 is fast enough and the unit is quiet enough which to me represents good value. Using Carbon Copy Cloner to mirror the 2 drives.

Does the job with no headache.

By Preston
Rated 5 out of 5
Date: 2026-01-21

The best kind of practical use product is the kind you don't have to think about. With this, I don't. I just plugged it in and it worked. It did come with a high speed type-c to c, which I appreciated. I had to get Type-A to C for my case, but I get why they don't include both.

See any errors on this page?

Since this is not a raid enclosure, does that ...

Since this is not a raid enclosure, does that mean all 4 drives format into one large drive? or as 4 single drives?
Asked by: Kevin
The TerraMaster D4-320 4-Bay USB 3.2 Gen 2 Enclosure, B&H # TED4320, would recognize the drives as 4 single drives; however, you could use tools built into your operating system to create what is referred to as a spanned drive, where it would combine all 4 into a single volume without using RAID. In macOS, it is called a Concatenated (JBOD) set, and you can use Disk Utility to create a set; on Windows, it is known as a Spanned volume, and you can use disk management to create it.
Answered by: Miguel M
Date published: 2026-01-25

How does this unit accommodate SSD's? Is there an ...

How does this unit accommodate SSD's? Is there an adapter?
Asked by: Sney
The bays on the TerraMaster D4-320 4-Bay USB 3.2 Gen 2 Enclosure can already accommodate 2.5" SSDs; you do not need to use an adapter.
Answered by: JP A
Date published: 2025-11-17
  • y_2026, m_6, d_2, h_13CST
  • bvseo_bulk, prod_bvqa, vn_bulk_3.0.46
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_2
  • loc_en_US, sid_1834179, prod, sort_[SortEntry(order=HAS_STAFF_ANSWERS, direction=DESCENDING)]
  • clientName_bhphotovideo
Whatever You Need, We've Got It