Terramaster D4 SSD Review

Terramaster D4 SSD USB4 Enclosure Review

The Terramaster D4 SSD is a four-bay all-flash storage enclosure designed for high-speed external data handling over USB4 connectivity, offering bandwidth of up to 40Gbps. It accommodates four PCIe NVMe M.2 2280 SSDs, allowing a maximum raw capacity of 32TB when fitted with 8TB drives, with larger capacities possible pending future verification. Aimed at professional workflows such as media creation, high-resolution video production, and post-production editing, it is also marketed for gaming environments where low-latency loading and direct game installation are desired. The enclosure does not feature built-in RAID capabilities, instead operating in single-drive mode and relying on the host computer or third-party software for RAID management when required. Measuring 138 x 60 x 140 mm and weighing 392grams, it offers a compact footprint suitable for desktop or mobile editing setups. With active cooling via dual smart fans, wide voltage power input for flexible deployment, and compatibility across USB4, Thunderbolt 3/4/5, and USB 3.x interfaces, the D4 SSD is designed to integrate seamlessly with both Mac and Windows systems, including use as a Mac OS boot drive or as direct expansion for NAS devices with supported ports.

Terramaster D4 SSD Review – Quick Conclusion

The Terramaster D4 SSD is a compact four-bay USB4 NVMe enclosure that delivers high transfer speeds through dedicated PCIe Gen4 x1 lane allocation per drive, managed by the ASMedia ASM2464PDX controller for consistent scaling across single or multiple SSD configurations. While it lacks built-in hardware RAID, this simplifies design, reduces power draw, and allows users to manage RAID through their host system or software tools, offering flexibility for performance or redundancy needs. In testing, it sustained multi-gigabyte throughput under prolonged load without thermal throttling, aided by its dual smart-fan cooling system and low-noise operation, making it suitable for studios and mobile production environments. Its wide voltage input range supports power from standard laptop and mini-PC adapters, and cross-platform compatibility extends to Thunderbolt 3/4/5 and USB 3.x systems, with support for multiple file systems across macOS, Windows, and Linux. Best suited for professionals in media production, post-processing, and high-resolution video editing, the D4 SSD offers a strong balance of speed, efficiency, and portability, though buyers should account for the cost of high-capacity NVMe drives and may wish to add heatsinks for heavy workloads.

BUILD - 10/10

HARDWARE - 7/10

PERFORMANCE - 8/10

PRICE - 9/10

VALUE - 8/10

8.4

PROS

👍🏻High-speed USB4 interface with up to 40Gbps bandwidth, delivering strong multi-bay NVMe performance.
👍🏻Dedicated PCIe Gen4 x1 lane allocation per slot ensures predictable scaling without lane-sharing bottlenecks.
👍🏻Compact and lightweight chassis with active cooling and low noise output, suitable for quiet work environments.
👍🏻Cross-platform compatibility with Thunderbolt 3/4/5 and USB 3.x, supporting multiple file systems for macOS, Windows, and Linux use.
👍🏻Low power consumption, even under full load, making it efficient for continuous operation.

CONS

👎🏻No built-in hardware RAID functionality, requiring RAID to be managed by the host system or third-party software.
👎🏻No included NVMe heatsinks, which may be needed for sustained heavy workloads.
👎🏻Performance dependent on host system capabilities and RAID configuration, limiting maximum speeds in some setups.

Terramaster D4 SSD NAS
Amazon in Your Region for the Terramaster D4 SSD @ $299	B&H for the Terramaster D4 SSD USB4 DAS@ $299.99

Terramaster D4 SSD Review -Design and Storage

The Terramaster D4 SSD adopts a compact and minimalist design that prioritises space efficiency while accommodating high-performance M.2 NVMe storage. The chassis is constructed with a combination of metal and reinforced plastic to balance durability with weight reduction, making it practical for desktop setups or mobile editing stations. Measuring 138mm in height, 60mm in width, and 140mm in depth, it has a footprint smaller than many portable RAID enclosures yet houses four internal M.2 2280 slots. Ventilation is a key part of the design, with perforations along the chassis and an internal airflow path from the bottom intake to the top exhaust. This airflow design is paired with a smart dual-fan system to keep temperatures stable under sustained workloads. The minimalist exterior is free of unnecessary styling, focusing instead on functionality and discrete operation in professional environments.

Internally, the storage layout is based entirely on NVMe architecture, with each of the four bays supporting PCIe Gen4 x1 bandwidth allocation. This ensures each SSD has dedicated lane access to maintain predictable throughput, rather than sharing limited controller bandwidth as seen in some lower-cost enclosures. The D4 SSD supports up to 8TB per drive, giving a maximum raw capacity of 32TB, though higher capacities may be supported as larger consumer and enterprise NVMe drives are verified. This design choice prioritises performance consistency and reduces the risk of bottlenecks, particularly when drives are accessed simultaneously for large file transfers or multi-stream media editing.

The enclosure is not equipped with a hardware RAID controller, meaning all drives operate in independent single-disk mode by default. Users wishing to configure RAID 0, 1, or other levels must do so using their operating system’s built-in storage management tools or third-party RAID software. This approach reduces internal complexity, lowers power draw, and avoids thermal buildup from additional processing hardware, but shifts configuration responsibility to the user. For some workflows, particularly those involving high-performance NVMe SSDs, host-managed RAID can still deliver substantial speed gains without affecting compatibility.

For cooling, the D4 SSD uses an active design with two 50mm temperature-controlled fans. These are managed by four onboard temperature sensors, adjusting fan speeds based on workload and heat generation. The airflow design is optimised to pass directly over the NVMe modules and the mainboard’s heat-generating components. While the unit does not include NVMe heatsinks by default, there is space to install aftermarket options if desired. Terramaster’s decision not to bundle heatsinks reflects a balance between cost and compatibility, as different SSDs have varying thermal needs, and some users may prefer specific heatsink designs.

From a noise and usability standpoint, the D4 SSD is intended to operate unobtrusively in environments such as home offices, studios, and editing suites. In standby mode with SSDs installed, the noise level is measured at 19dB(A), making it quieter than many desktop PCs and suitable for near-silent workspaces. Combined with its small physical footprint, this makes it a storage device that can be positioned close to the user without being a distraction, even under full load during extended transfers or media rendering sessions.

Terramaster D4 SSD Review – Internal Hardware

Inside the Terramaster D4 SSD, the hardware is built around a dedicated USB4 bridge controller, the ASMedia ASM2464PDX, which is designed to maintain high throughput across multiple NVMe drives without the lane bottleneck issues found in some lower-cost enclosures. Each M.2 slot is wired for PCIe Gen4 x1 bandwidth, providing up to 2,000MB/s potential per drive, which is then aggregated and managed through the USB4 interface.

This design ensures predictable scaling in both single-drive and multi-drive use, with performance closely tied to the host system’s RAID or file management configuration. The PCB is perforated in multiple areas to enhance passive airflow in conjunction with the active cooling fans, helping to maintain SSD performance during sustained workloads such as large file transfers or continuous video editing.

The storage slots themselves support PCIe NVMe M.2 2280 SSDs, making the D4 SSD compatible with a wide range of consumer and professional-grade drives. While the official capacity limit is listed as 8TB per drive, the enclosure is not restricted by proprietary firmware, allowing for potential support of larger modules as they become available. The absence of hardware RAID keeps internal processing simple, reducing latency and power draw, while allowing the enclosure to work equally well in macOS, Windows, and certain NAS expansion scenarios where the RAID logic is handled externally. Additionally, the enclosure supports multiple file systems including NTFS, APFS, exFAT, FAT32, and EXT4, depending on the host environment.

Power delivery to the enclosure is handled through a 24W external adapter, with a wide input voltage range of 12V to 20V for compatibility with common laptop and mini-PC power supplies. This not only makes it more versatile for travel or integration into mobile production setups but also reduces the need for proprietary adapters.

The included USB4 Type-C cable is 0.8m in length and rated for up to 80Gbps, significantly higher than the device’s 40Gbps requirement, ensuring minimal signal degradation over time. Thermal and power management are monitored by four internal sensors, which regulate the fan speeds to balance cooling and noise.

Terramaster D4 SSD Review – Connectivity

The Terramaster D4 SSD keeps its external connectivity simple, focusing on delivering the highest possible throughput over a single interface. The primary connection is a USB4 Type-C port located on the rear of the unit, providing up to 40Gbps of bandwidth when used with a compatible host device. This interface also ensures backward compatibility with Thunderbolt 3, Thunderbolt 4, Thunderbolt 5, and USB 3.x standards, although maximum speeds will vary depending on the protocol supported by the connected system. This approach makes the D4 SSD suitable for a wide range of setups, from modern Mac computers and high-end Windows workstations to certain NAS devices that offer USB4 or Thunderbolt connectivity for expansion.

The unit does not draw power from the USB4 connection, which is essential given the requirements of running four NVMe drives under load. This separation ensures stable power delivery regardless of the workload, preventing thermal throttling or performance drops caused by insufficient bus power.

The only other physical interface elements are the cooling ventilation openings, the power button, and status indicators. The ventilation is positioned to support the enclosure’s top-to-bottom airflow, with exhaust positioned to avoid heat recirculation. The power button is recessed to prevent accidental shutdowns, and the indicator lights provide a quick visual status of drive activity. While the D4 SSD avoids additional ports such as USB hubs or SD card readers, this streamlined design prioritises stability and speed for storage operations, aligning with its role as a dedicated high-bandwidth storage enclosure rather than a multifunction docking station.

Terramaster D4 SSD Review – Performance and Tests

In practical testing, the Terramaster D4 SSD demonstrated performance levels consistent with the capabilities of its USB4 interface and internal PCIe lane allocation. When fitted with a single PCIe Gen4 NVMe SSD and connected to a compatible Windows host system, sequential transfer rates reached around 1,480MB/s for reads and 1,140MB/s for writes in CrystalDiskMark, with mixed 70/30 read/write workloads averaging 1,286MB/s.

AJA System Test results with a repeated 1GB file showed roughly 1,400MB/s read and 1,300MB/s write, while ATTO Disk Benchmark recorded peaks of 1.57GB/s read and up to 1.5GB/s write.

These results represent roughly three-quarters of the theoretical maximum per-lane Gen4 x1 performance, with minor variations attributable to SSD model and host configuration.

With four SSDs installed and configured in RAID 0 via Windows Disk Management, throughput scaled significantly.

In AJA testing, read speeds reached 2,500MB/s and writes 2,300MB/s. CrystalDiskMark produced 2,047MB/s reads and 1,927MB/s writes in sequential tests, with mixed workloads at around 1,799MB/s.

ATTO testing peaked at approximately 2.93GB/s read and 2.66GB/s write. These figures are below the absolute maximum possible for USB4 but remain strong for a host-managed RAID array without dedicated hardware acceleration.

The results indicate that with a more capable RAID implementation, sustained speeds above 3GB/s would be achievable, making the D4 SSD suitable for high-bandwidth applications such as multi-stream 4K or 6K video editing. Thermal performance was another key testing area given the high-speed NVMe drives involved. Under sustained load with all four SSDs active, the enclosure’s dual-fan cooling system maintained stable operating temperatures without noticeable thermal throttling. Noise output, even at maximum fan speed, remained low enough for close-proximity use in an editing suite or home office. The absence of included NVMe heatsinks did not lead to significant overheating in tests, though installing aftermarket heatsinks could be beneficial for prolonged heavy workloads or in warmer environments.

Power consumption measurements showed efficient operation relative to its performance. With all drives in hibernation, draw was close to 1W; in standby, it was 3–4W; and at full load, the system used only 5–6W. This efficiency, combined with the wide voltage input support, makes the D4 SSD practical for mobile production setups and continuous desktop use without significant power overhead. Compatibility was confirmed across both macOS and Windows systems, with macOS tests achieving up to 3,257MB/s reads and 3,192MB/s writes using four Samsung 990 PRO 4TB SSDs in RAID 0 on a Mac mini with an Apple M4 chip.

Terramaster D4 SSD Review – Verdict and Conclusion

The Terramaster D4 SSD positions itself as a compact, high-speed, and flexible all-flash enclosure for users who require consistent bandwidth and expandable capacity over USB4. Its PCIe Gen4 x1 lane allocation per drive, paired with the ASMedia ASM2464PDX controller, ensures that performance scales predictably from single-drive use to fully populated configurations without the bottlenecks common in lower-end enclosures that multiplex lanes. While the absence of built-in hardware RAID will be seen as a limitation for users wanting an all-in-one solution, the decision to leave RAID management to the host system helps keep the enclosure’s design simpler, power consumption lower, and thermal output under better control. This host-managed approach also allows greater flexibility in choosing software RAID solutions optimised for specific workflows, whether for performance (RAID 0), redundancy (RAID 1), or other advanced configurations. Combined with its small footprint, professional-grade cooling, and wide voltage input range, the D4 SSD fits naturally into both fixed and mobile setups where reliable sustained throughput is essential.

From a value and application standpoint, the D4 SSD’s test results put it among the faster multi-bay USB4 NVMe enclosures currently available, especially given its ability to sustain multi-gigabyte transfers under prolonged load without thermal throttling. It is particularly well-suited to professionals in media production, post-processing, and high-resolution video editing who need large, portable, and quiet storage capable of handling multiple uncompressed video streams in real time. The unit’s quiet operation, even when all drives are active, makes it practical for use in audio-sensitive environments, and its compatibility with Thunderbolt 3, 4, and 5 as well as USB 3.x protocols expands its usability across a wide variety of systems. Potential buyers should, however, factor in the additional cost of populating all four slots with high-capacity NVMe SSDs and consider adding aftermarket heatsinks for continuous heavy workloads, as none are included. For those who already operate in environments where RAID is managed externally or within the operating system, the D4 SSD represents a balanced combination of speed, efficiency, and build quality that should appeal to both Windows and macOS professionals seeking long-term, high-performance storage expansion.

Terramaster D4 SSD NAS
Amazon in Your Region for the Terramaster D4 SSD @ $299	B&H for the Terramaster D4 SSD USB4 DAS@ $299.99

PROs of the Terramaster D4 SSD

CONs of the Terramaster D4 SSD

High-speed USB4 interface with up to 40Gbps bandwidth, delivering strong multi-bay NVMe performance. Dedicated PCIe Gen4 x1 lane allocation per slot ensures predictable scaling without lane-sharing bottlenecks. Compact and lightweight chassis with active cooling and low noise output, suitable for quiet work environments. Cross-platform compatibility with Thunderbolt 3/4/5 and USB 3.x, supporting multiple file systems for macOS, Windows, and Linux use. Low power consumption, even under full load, making it efficient for continuous operation.

No built-in hardware RAID functionality, requiring RAID to be managed by the host system or third-party software. No included NVMe heatsinks, which may be needed for sustained heavy workloads. Performance dependent on host system capabilities and RAID configuration, limiting maximum speeds in some setups.

 

📧 SUBSCRIBE TO OUR NEWSLETTER 🔔

🔒 Join Inner Circle

This description contains links to Amazon. These links will take you to some of the products mentioned in today's content. As an Amazon Associate, I earn from qualifying purchases. Visit the NASCompares Deal Finder to find the best place to buy this device in your region, based on Service, Support and Reputation - Just Search for your NAS Drive in the Box Below

Need Advice on Data Storage from an Expert?

Finally, for free advice about your setup, just leave a message in the comments below here at NASCompares.com and we will get back to you. Need Help? Where possible (and where appropriate) please provide as much information about your requirements, as then I can arrange the best answer and solution to your needs. Do not worry about your e-mail address being required, it will NOT be used in a mailing list and will NOT be used in any way other than to respond to your enquiry. TRY CHAT Terms and Conditions   Alternatively, why not ask me on the ASK NASCompares forum, by clicking the button below. This is a community hub that serves as a place that I can answer your question, chew the fat, share new release information and even get corrections posted. I will always get around to answering ALL queries, but as a one-man operation, I cannot promise speed! So by sharing your query in the ASK NASCompares section below, you can get a better range of solutions and suggestions, alongside my own.

☕ WE LOVE COFFEE ☕