
Our Verdict
Pros
- USB4
- Portable
- Powerful
Cons
- None
Should you buy it?
AvoidConsiderShortlistBuyIntroduction & Drive Details
The TERRAMASTER D4 is a premium, professional product, and if you demand the very best in portable and universally compatible storage, then this is it. This premium enclosure with its native USB interface delivers lightning-fast speeds of up to 3,800MB/s. Because the onboard ASM2464PDX controller is a native USB device, it offers universal compatibility, including USB 40Gbps, USB 20Gbps, USB 10Gbps, USB 5Gbps, Thunderbolt 5, Thunderbolt 4, and Thunderbolt 3. It can even work on USB 2 ports with a Type-C to Type-A cable.
This 4-bay M.2 NVMe enclosure can facilitate up to a massive 32TB storage capacity in a compact design with whisper-quiet operation. The device features an advanced active cooling system with temperature-controlled fans that keep the NVMe external enclosure silent (19dB(A) in standby) even under heavy loads. Four internal temperature sensors ensure optimal heat dissipation, protecting your SSDs while maintaining a distraction-free environment.
As stated, the D4 SSD enclosure is powered by an ASM2464PDX controller. The D4 SSD features four individual bays, with a single PCIe Gen4 lane connecting each bay with the controller. As a single individual disk throughput maxes out at around 1,600 MB/s, when RAIDing 3 or more bays together via software RAID, throughput can exceed 3,800 MB/s, which is about the upper limit of USB 4.
| Item | Details |
|---|---|
| Model | TERRAMASTER D4 SSD 4-Bay NVMe Enclosure |
| MSRP | $300 |
| Model Number | D4 SSD |
| Interface | USB 4 |
| Form Factor | Desktop Portable |
| Performance | Up to 3,257 MB/s |
| Warranty | 2-Years Limited |
For our testing purposes, we decided to populate and RAID 0 three of the four bays with 8TB drives for an array of 24TB in raw capacity and utilize the fourth bay as a single 4TB disk:

This configuration allows us to test both maximum USB 4 throughput as well as single lane, single disk performance, which we will be presenting throughout the review. All benchmark results will be presented as single disk followed by the array.
Drive Details









When you buy a TERRAMASTER device, you get the value-added bonus of free software, enabling you to get the most out of your storage solution with easy-to-use tools, including the TPC Backupper PC backup tool and the TDAS Mobile backup app for iOS and Android devices. Click HERE to download them both from the D4 SSD product page.
Our Latest SOHO NAS/DAS Review Coverage
Note: Performance will vary based on what SSDs are employed by the end user, and how or if Windows software RAID is employed.
Synthetic Benchmarks: CDM, ATTO & Blackmagic
CrystalDiskMark




The D4 SSD enclosure is advertised as capable of delivering up to 1,608 MB/s single drive throughput and up to 3,224 MB/s RAID 0 throughput. With our configuration, we easily exceed both quoted up to throughput specifications. Excellent.
ATTO




ATTO verifies our test subject as capable of delivering full sequential throughput at 32K transfers at the standard test queue depth of 4, with a single drive, and at 256K with our 3-drive array.
Blackmagic




As these results indicate, the D4 SSD enclosure can be used as a portable scratch disk for video editing duties. Very few devices can handle this demanding use case scenario at this high level, which speaks to the powerful performance potential of this device. Outstanding.
Real-World Testing: PCMark 10, 3DMark SSD Gaming & Transfer Rates
PCMark 10 Data Drive Benchmark
The Data Drive Benchmark is designed to test drives that are used for storing files rather than applications. You can also use this test with NAS drives, USB sticks, memory cards, and other external storage devices.
The Data Drive Benchmark uses 3 traces, running 3 passes with each trace as follows:
- Copying 339 JPEG files, 2.37 GB in total, into the target drive (write test).
- Making a copy of the JPEG files (read-write test).
- Copying the JPEG files to another drive (read test).



Again, results here verify that on-device editing can be done at the highest level for a portable storage device. Impressive.
3DMark SSD Gaming Test
UL's newest 3DMark SSD Gaming Test is the most comprehensive SSD gaming test ever devised. We consider it superior to testing against games themselves because, as a trace, it is much more consistent than variations that will occur between runs on the actual game itself. This test is the same as running the actual game, just without the inconsistencies inherent to application testing. In short, we believe that this is the world's best way to test an SSDs gaming prowess and accurately compare it against competing SSDs. The 3DMark SSD Gaming Test measures and scores the following:
- Loading Battlefield V from launch to the main menu.
- Loading Call of Duty Black Ops 4 from launch to the main menu.
- Loading Overwatch from launch to the main menu.
- Recording a 1080p gameplay video at 60 FPS with OBS (Open Broadcaster Software) while playing Overwatch.
- Installing The Outer Worlds from the Epic Games Launcher.
- Saving game progress in The Outer Worlds.
- Copying the Steam folder for Counter-Strike Global Offensive from an external SSD to the system drive.



Gaming is a performance metric that matters to most DIY consumers, especially to the enthusiast crowd that TweakTown caters to. We are now including gaming performance as a part of our external SSD reviews, as using portable storage for gaming duties is very popular among avid gamers.
Portable, fully compatible storage is a nice complement to any console or PC gaming device.
If mass portable and powerful gaming storage is what you need in your life, then as you can see, the D4 SSD enclosure can deliver more than any other portable device we've come across. Yes, you see that correctly, the single drive is indeed outperforming the array here. Not exactly sure why that is, but we tested several times and verified that in this one testing scenario, this is indeed the case.
DiskBench - Transfer Rates






We brutalize our test subjects with our extremely hard-to-digest 100GB data block. This data block is the same one we use for our internal SSD testing and is composed of more than 62K files. 100GB is probably right at the upper limit for a single transfer, so as we see it, this is a much more realistic test scenario than a sustained filling of the entire drive.
Single drive or array, huge chunks of data can be written at an incredible rate. Again, it all depends on the choice of SSDs employed by the end user.
Final Thoughts

We are of the opinion that the TERRAMASTER D4 SSD enclosure is the best of its kind, making it a must-have for everyone who needs massive amounts of universally compatible, quiet, and powerful portable storage. Editor's Choice.


