TerraMaster D4-320U Ultra-Short 4-Bay 1U Rackmount USB3.2 DAS

TerraMaster Technology Co. Ltd. introduces the D4-320U, a compact 1U 4-bay direct-attached storage (DAS) enclosure designed for small offices, home users, and IT environments.

Combining a space-saving rackmount design, massive 88TB storage capacity, and lightning-fast 10Gb USB 3.2 Gen2 performance, the D4-320U delivers versatility and efficiency for modern data demands.

D4-320U Key Features :

• Compact Design for Deployment
  The D4-320U redefines convenience with its miniaturized 1U rackmount form factor. Measuring just 241mm (9.49 inches) in depth, 50% shorter than traditional chassis and weighing 3.2kg, this sleek enclosure fits effortlessly into standard server racks without the need for rails, simplifying installation. Its space-efficient design maximizes room utilization in data centers, storage closets, stairwells, or offices, making it a choice for small businesses and SOHO users seeking centralized storage solutions.
• Massive 88TB Storage Capacity
  With support for up to 4 drives, the D4-320U offers a staggering maximum capacity of 88TB (using 22TB drives, with larger capacities pending compatibility verification). Operating in single-disk mode by default, users can leverage 3rd-party software RAID tools to create arrays, catering to extensive storage needs from media libraries to enterprise backups.
• High-Speed Data Transfer at 10Gb
  Equipped with the USB 3.2 Gen2 protocol, the D4-320U achieves a blazing 10Gb bandwidth. When paired with 4x8TB WD Red HDDs, it delivers RW speeds of up to 1,016MB/s. Even with a single 1TB WD Red SSD, users can read speeds of 510MB/s. This performance ensures rapid data access and transfer, for professionals and enthusiasts alike.

• Expandable NAS Integration
  Optimized for TerraMaster NAS devices running TOS 5.1 or higher, the D4-320U connects via USB to expand storage pools and create arrays through the TOS NAS OS system.
  This feature makes it a powerful companion for users looking to scale their NAS capacity with ease.

• Plug-and-Play Simplicity
  The D4-320U offers true driver-free, plug-and-play functionality, supporting macOS, Windows, Linux, Ubuntu, TrueNAS, Unraid, and more. Compatible with USB protocols, it connects to PCs, TVs, servers, and set-top boxes. Included 0.8m USB A-to-C and C-to-C cables ensure compatibility with USB 3.0, 3.1, 3.2, Thunderbolt 3, and Thunderbolt 4 interfaces for stable, high-speed connectivity.

Safety and Efficiency Features :

• Power Protection: Advanced safeguards prevent damage from mismatched power inputs, ensuring hardware longevity.
• Power Recovery: Smart memory resumes the device’s prior state after power outages – staying off after a normal shutdown or auto-starting post-disruption – for unattended server or NAS setups.
• Intelligent Hibernation: Drives enter sleep mode with the host system, reducing wear and energy use while extending lifespan.
• Quiet Cooling: A smart, temperature-controlled low-noise fan and optimized airflow keep drives cool and quiet, even under full load.

Automated Backups Made Easy
With the company’s TPC Backupper for Windows (8/8.1/10/11), users can schedule incremental or differential backups of folders and partitions to the D4-320U or a TerraMaster NAS.

 D5-310 5-bay RAID 

The D5-310 5-bay RAID storage device was released at the same time, forming a ‘enterprise + personal’ dual product line layout with the D4-320U. Users can purchase new products through the company’s Official Mall and authorized channels, and a 2 year warranty service.