TERRAMASTER D4-320 External Hard Drive Enclosure – 4bay USB
TERRAMASTER D4-320 External Hard Drive Enclosure – 4bay USB 3.2 Gen2 10Gbps Type-C USB Storage Hot Swappable Plug and Play (Diskless)
New Upgrade, Refreshed Experience
As an upgrade to the classic D4-300, the D4-320 hard drive enclosure 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.
Enhanced Speed and Performance:
Utilizing USB 3.2 Gen2 protocol, the D4-320 USB storage achieves lightning-fast data transfer speeds of up to 10 Gbps, doubling the speed of its predecessor (D4-300). Whether handling multiple hard drives concurrently or a single drive, the D4-320 consistently delivers exceptional performance, reaching read/write speeds of up to 1,016 MB/s (combined read/write with SATA III HDDs x 4). Even with just one SSD installed, the read speed effortlessly reaches 510 MB/s (SATA III 1TB SSD). 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.
Flexible and Compatible Connectivity:
The D4-320 direct attached storage boasts strong interface compatibility with its USB Type-C interface, providing seamless connections to various computer interfaces, including USB 3.0, USB 3.1, USB 3.2, Thunderbolt 3, and Thunderbolt 4. Its hot-swappable support and driverless, plug-and-play functionality make it a versatile and user-friendly storage solution, compatible with different operating systems and devices.
Convenient and Efficient Hard Drive Management:
The D4-320 HDD enclosure introduces a revolutionary tool-free hard drive bracket with a Push-lock design, allowing quick and secure installation without the need for tools. This innovative design ensures stable data transmission, greatly enhancing the efficiency of hard drive replacement. Swapping hard drives becomes a seamless process, providing added convenience for users who frequently switch drives. Additionally, the D4-320 is exceptionally quiet during its operation, thanks to its specialized sound-absorbing panels and vibration damping, which reduce noise levels by up to 50% compared to the previous generation, dropping below 21 dB(A) in standby mode for a remarkably quiet user environment.
Versatile Storage Expansion:
With support for up to four hard drives, each with a maximum capacity of 22TB, the D4-320 offers a powerful storage expansion of up to 88TB. 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.
TERRAMASTER HDD Enclosure Comparison
 TERRAMASTER D4-320 |  TERRAMASTER D6-320 |  TERRAMASTER D5 Hybrid |  TERRAMASTER D4-300 | |
| Customer Reviews | 4.3 out of 5 stars 555 | 4.3 out of 5 stars 555 | 5.0 out of 5 stars 1 | 4.3 out of 5 stars 555 |
| Price | £179.99 | £299.99 | £209.99 | £149.99 |
| Drive Bays | 4 | 6 | 2 | 4 |
| Interface | USB3.2 10Gpbs Type C | USB3.2 10Gpbs Type C | USB3.2 10Gpbs Type C | USB3.1 5Gpbs Type C |
| Max. number of HDDs/SSDs | 4 x 2.5″ or 3.5″ SATA 6Gb/s | 6 x 2.5″ or 3.5″ SATA 6Gb/s | 2 x SATA HDD/SSD; 3 x M.2 SSD | 4 x 2.5″ or 3.5″ SATA 6Gb/s |
| Max. Storage | 88TB (22TB x 4) | 132TB (22TB x 6) | 68TB (22TB x 2 + 8TB x 3) | 88TB (22TB x 4) |
| Reading Speed (max.) | 1025MB/s (4 SSD, Single Disk) | 1030MB/s (6 SSD, Single Disk) | 980MB/s (1 NVMe SSD, Single) | 420MB/s (tested by 4 SSD) |
| Writing Speed (max.) | 1016MB/s (4 SSD, Single Disk) | 1005MB/s (6 SSD, Single Disk) | 866MB/s (1 NVMe SSD, Single) | 390MB/s (tested by 4 SSD) |
| Hardware RAID | ✘ | ✘ | ✔ | ✘ |
| RAID Mode | NO RAID | NO RAID | HDD1&2 – RAID 0/1/Single/JBOD | NO RAID |
| RAID Features | NO RAID, only Individual disks | NO RAID, only Individual disks | 2 + 3 RAID mode | NO RAID, only Individual disks |
| RAID Auto-rebuilding | No | No | RAID1 | No |
| Push-Lock Tray | ✔ | ✔ | ✔ | ✘ |
Faster and more reliable than rivals
I’ve tried several enclosures, and this is the one I’m sticking with and recommend. I’ve deliberately waited a few months after purchasing it before reviewing it, so it’s had a good testing.
Starting with the bad. It’s a bit flimsy, certainly for the price. The trays are plastic, and you have to load the hard drives carefully – it would be easy to snap the plastic retainer clip. Noise? Well, it’s the loudest of any enclosure I’ve used, but no one could call it noisy. Occasionally, when one of the disks spins up I’m alerted to the sound, but it blends into the background sounds of my quiet study pretty easily, and it’s not disturbing at all.
More serious, as some others have noted, is that the USB connection isn’t particularly secure. A slight knock and it’s easy for the drives to disconnect. Solution: put it somewhere where it won’t get knocked. Mine is under my desk, and there’s no real problem.
But these are minor problems, and outweighed by the good side of it. It seems to use a different chip from similar devices. I read this somewhere, and it’s borne out by the fact that the internal drives are genuinely hot-swappable. Most enclosures, if you take one drive out, all the others disconnect. Not this one. It’s possible to swap one drive and replace it without disturbing the others. This makes me think the drives are in some sense independent, and this is confirmed by the speed of the thing: other enclosures can never read faster than the speed of one drive, whereas this most definitely can.
In this Terramaster, individual drives give 200Mb/s maximum, the same as other enclosures, and the same as a basic one-drive caddy; however, when reading from two or more drives simultaneously (as, for instance, when using a software RAID) the Terramaster gives a comfortable 300MB/s, whereas other enclosures aren’t any faster (and are often slower) than a single drive.
But perhaps the most telling advantage is that it hasn’t corrupted any disks (yet). Every other enclosure I’ve used has, relatively quickly, produced hardware errors (measured by Apple’s Disk Utility or DriveDX) and occasionally rendered a drive totally unreadable. This Terramaster hasn’t shown any problems of that kind.
Suffice it to say that this enclosure is the one I use, and all the others have been sent back. It is rather overpriced for what it is – it’s not designed for network storage, and there’s no hardware RAID – but for my needs I haven’t found a better enclosure despite extensive testing of others.
Embraces old tech - but that's good
Technology is advancing so far these days sometimes it’s hard to keep up. And it seems that there is no area of technology that is under development. That’s why a box with four spinning disks in it seems like going back to the stone age in tech terms, but as any rabid Redditor well tell you there is no substitute for bang for buck, resilience, and longevity than spinning disks in an array as a means of backing up your data ( ps always remember the 3, 2, 1 backup rule – Startpage search that if you don’t know what that means).
What I like about this unit is that it is JBOD or just a bunch of disks and that means maximum versatility. Avoid similar disk housings that have built in raid functionality because if the box fails you’re stuck with your data locked into whatever proprietary raid came with the box.
I had four spare disks from a previous nas and they fitted and initialised no problem. The unit connected to the back of my nas via the included usb cable – another bonus as the cable isn’t proprietary if it needs replacing.
So far, so good. Also good is the build quality. I have to qualify that statement in that the build quality is acceptable for the price. The plastic silver outside shell comes over as being brittle and cheap. However, the disk mounts and disk bay closure are perfectly functional and to be honest that’s where quality should be focused.
On to the not so good then. This unit is noisy from fan noise, spinning disks, and in my unit there was a particularly annoying rattle from the chassis, probably due to those brittle plastics being affected by vibrations from all the spinny bits. So I would recommend tucking this unit away under the stairs, or somewhere else or of earshot.
So there you have it. Agricultural tech in a new-ish housing for four spinny disks in a box. Yes, it’s not the cutting edge, but that’s a good thing when it comes to reliably storing your precious data.
Works perfect for HDD (no installation required)
Does what it says and lets you use multiple internal hard drives from a external enclosure/bay.
Problems you could run into:
This is only the second external hdd enclosure i have bought and used and I encountered a problem.
I pulled my single hdd from a previous single hdd enclosure and installed into this but it refused to let me access the data. To be precise it would not let me even use it as a drive until formating it wiping the data.
I did try and see if it was a drive letter issue but windows disk manager did not give me option (greyed out).
Just something you should consider or research into if your in the same boat thinkingnout upgrading to another DAS. It is possible however I just dont know how to set up existing hdds.
Initial impression is very good
D4-320 (4bay,non-raid) I’ve been using it a week and so far it’s worked well.
Well packaged, new black design is nice, very on trend and is better in the flesh than in the product visuals. The case is metal with plastic front and back. Power unit/transformer is good, proper fused UK plug with shielded live and neutral (I mentioned this as sometimes these things come with dangerous/illegal plugs).
HDD Sata fits into the tray without the need for tools, clips in. SSD Sata screws in with provided screws, you will need small screwdriver. Fan is effective and quiet. USB3.2 works as described but obviously restricted by the speed of the drive you choose to use. I am using this with a Mac 13.6.6 and I have also tested it on an M2 Mac and it works on that as well. I am using a Samsung SSD and two Seagate Ironwolf HDD. The SSD gave me (485MB/s write) (523MB/s read) and the HDD (161MB/s write & read). The SSD runs silent HDD a bit noisy but that is the drive and to be expected. The sleep feature works well, drives remain mounted and when you click on them they wake up. Only niggle was no instructions in box, you are directed online with a QR code and you have to give them your email, I think this might possible extend the warranty but it’s unwanted data capture. They have a recommended drive list on their website its for the D4-300 but I assumed it was still relevant. If your using Windows you can download their backup program. I’m just using it as JBOD. Top line – Im very pleased so far, hopefully it will prove reliable. Only time will tell.
Easy to set up DAS storage unit as good as a NAS serve
Dead easy to set up and pc windows explorer found the unit straight away. Running plex media server off 4 drives 8tb 8tb 4tb 3tb with over 3000 films and 200 plus TV shows full seasons and the DAS doesn’t seem to have any bottleneck issues showing up as 620mbps upload and 712mbps download in a read write test which is better than 8 expected also very quiet considering it has 2 60cm fans looks really nice weight wise it’s heavy-duty and feels nice and looks nice with its metal finish. Definitely worth a buy the usb c to usb 3.2 is also brilliant idea as well space saver and free up usb connections.
Definitely recommend this item and company 10/10
This is a DAS ... Desktop Attached Storage for those that do not know.
This device connects to your computer or other device, not directly to the network (In case you know what that is.)
Buy your HDD or SDD (will need a 2.5″ to 3.5″ adapter/caddy) and install it. For the 3.5″ drive that I used it was …
1. DO NOT CONNECT TO POWER YET.
2. Pull out one of the caddies
3. Take off the screw hole covers … it is all plastic so BE GENTLE.
And if NOT broken no screw will be needed.
4. Sit drive in the space … Label up, Connects to the back.
5. Put screw hole covers backon.
6. Push drive into the available slow and close the handle.
7. Connect the unit to power and the USB cable to the USB A slot on your computer (which is already on 😉 )
8. I needed to then go into “Computer Management”, where I decided how I was going to format my drive,
into 1 or more partitions, which I then assigned a drive letter to (for each partition). I formatted
each partition and now they appear in file manager.
You need to do this process for each HDD/SDD that you add to the TerraMaster.
I use this to keep backups on, so I neither keep it turned on all of the time, nor connected to a computer.
I use it on two computers. But I only needed to format it once, and selected the drive letters for each computer once (from the “Computer Management” program.
FYI: I was using Windows 7 and 11, the process was the same on each.
The TERRAMASTER D6-320 External Hard Drive Enclosure has truly transformed my storage experience. From the moment I unpacked it, the sleek and durable design caught my eye. The build quality reassured me that this was a product designed to last.
Setting up the enclosure was a delight; it’s user-friendly and doesn’t require technical expertise. The compatibility with various hard drive sizes adds to its versatility. I appreciate the thought put into the design, ensuring that it accommodates different storage needs seamlessly.
What truly sets the D6-320 apart is its impressive transfer speeds. The data transfer happens at lightning speed, saving me valuable time. Whether I’m backing up large files or accessing data on the go, the performance has been consistently reliable.
The quiet operation is another standout feature. Unlike some other enclosures I’ve used, the D6-320 runs quietly, making it suitable for both professional and home environments. No distracting noise, just efficient performance.
Overall, the TERRAMASTER D6-320 External Hard Drive Enclosure has become an integral part of my setup. It’s a reliable, high-performance solution for anyone seeking efficient external storage. If you’re in the market for a top-notch enclosure, this one gets a solid five stars from me!
We purchased this DAS for our home network and while we are impressed with the functionality of the item, it needs a price adjustment as it should cost significantly less (for what it is).
Overall the materials used are of adequate quality, there is a mix of aluminium and plastic, and while I don’t suspect the item arrived safe and well, I’m not sure if it will withstand long term frequent drive replacement / general use.
If this was stored away as a NAS we would feel more comfortable with the materials used. However it’s a DAS and therefore is likely to be on a desk, on show and getting more user interaction than a NAS. Therefore we are concerned that the materials may not hold up over time.
The DAS is relatively but does have a laudable hum, we would like to see larger fans used on the next integration to help reduce background noise from the fans.
Hard drives slot in nicely, and feel secure. They are quick and easy to replace and while the latches are a little flimsy, they are adequate, however long term use it yet to be seen, and we would like to see these made a little more robust on the next model evolution.
The design is much more interesting and authentically pleasing than its predecessor which is a huge positive, however we don’t think the price reflects the product and should be reduced to be more competitive with its peers.
Overall a very adequate product, slotted into a reasonable price bracket with adequate build and performance. It could have been a 5* magnificent product had they slightly adjusted the price, used slightly stronger materials and larger fans, but overall it’s a nice middle of the line product that will function well for most daily users needs.
This disk enclosure has been sufficient, simple and reliable for my setup. It has 4x8TB hard drives and I have had no issues with performance over USB-C.
My only frustration with this device is it’s cooling, there are two small fans at the back that pull air from the enclosure but you are unable to control the speed of these. Terramaster mentions the fans change depending on the temperature of the disks. However, I have had 4, 45 degree disks running operations in this enclosure and the fans have very little impact on cooling. If you’re planning on buying this device to serve a NAS solution, I would recommend an external cooling solution to the cabinet or room it’s ran in.
Purchased to take my various loose HDD drives, and tidy the area around my computer.
Initially nothing would ‘mount’ and whilst the drives picked up power and were recognised my computer was slow and reluctant to mount the drives. This turned out to be caused by the need for a sys restart…
Once restarted and software updates enabled all drives were recognised and mounted. I did have to ‘take ownership’ as previously the drives had been attached via an e-sata adaptor Linux can be a little ‘geeky’ in its operation but the unit works fine once you sit and work out your actions.
I purchased this unit because it is configured to operate in JBOD mode. This suits me and the way I archive my content.
I have started to move my podcast library onto one of the 3.5″HD drives from the 2.5HDD I download to. This latter now sits in the e-sata unit that previously held a 3.5″HDD so data transfers are now done at a reasonable speed.
I mistakenly thought the unit would ship with USB3-Ctype to USB3-Ctype lead; it doesn’t the lead supplied was USB3-A to USB3-C so not exactly what I had hoped.
One thing I did not expect was power sync. Turn off the controlling computer and the drives all shut down but the unit fans continue to run which was a bit of a result and unexpected.
I don’t use huge drives my standard archive is a 1TB WD Blue and I have three installed. There is space for a 4th drive so that may be filled by a 16TB WD Red and the other drives archived to that.
I think this unit offers the best compromise between speed and convenience.
It works on Linux which was the priority; some of the other JBOD boxes are a little shy about the OS they will attach to and work with.
An excellent enclosure.
Very easy to set up. Installing the drives is easy and requires no tools.
The enclosure runs quietly and cool, with its 2 fans. – This is with 4 drives in.
Importantly, the drives wake and sleep individually, as needed. This is an important feature for power-saving.
The drives will wake or sleep based on whatever Windows tells them to do – e.g., you can set them to sleep after 1 minute or never, depending on your preferences – they will follow whatever setting you have in Windows. This is unlike some other enclosures which either never turn off, or run for a set amount of time until turning off, or run all drives at the same time, even if they aren’t all needed. It will also sleep the drives when you turn off your PC and wake them when you restart the it. I am very glad they designed it this way. It was hard to find other enclosures that did this.
The enclosure even turns back on after a power failure, making it perfect if you need access to it remotely.
This enclosure really does tick all the boxes. Thanks Terramaster!
All-in-all, an excellent enclosure. I will definitely get more of these as I need to.
Bought to replace a very cheap single drive enclosure with connectivity issues.
This is not an expensive enclosure; although the main body is metal, the front fascia, back panel and drive holders are all plastic but is all seems sturdy enough.
On the plus side, it’s easy to fit 3.5″ drives into the screwless bays. 2.5″ drives do require screws which are included along with a screwdriver, blank bay labels, instructions, PSU and a USB C to USB A cable.
The PSU is a transformer with standard figure of 8 mains lead. Both PSU and mains cables are short and will just about reach from socket directly behind desk to the enclosure towards the back of the desk. A few extra inches would have been nice even if it meant increasing the price.
I bought a USB-C to USB-C 3.2 cable to connect to Mac mini M1. From unpacking to fully operational took about 20 minutes. The Mini picked up the drive straightaway. I haven’t benchmarked it but this set up is noticeably faster than the old caddy.
The rear cooling fans are so quiet I can’t hear them although, to be fair, I have one only drive fitted currently. The on / off switch is sited on the front with tiny but visible green LEDs confirming power and which drives are working.
So far, so good after three days of 8-10 hour usage.
Great simple alternative to a NAS/RAID or if you want to make a homebrew NAS
I bought this to create my own home media streaming server. At first I was going to buy a full RAID enclosure but after some deliberation I realised that a RAID was a little overkill for what I need. I was not going to be keeping any sensitive media or files on this and I keep other backups too. So in the event of a failure I could easily restore files. Having a RAID would limit the amount of storage I could create so I went for this.
I built my home server using the latest Rasp Pi with Open Media Vault and Portainer. OMV does allow you to create a backup routine and a software RAID if required.
Either way this enclosure works ideally if all you need is expandable and hot pluggable USB storage. I have 4 x 2TB drives in mine and use it to stream all my music and movies anywhere in my home via Jellyfin.
And if I need to I can just plug it into my desktop PC and copy stuff manually. However since the Rasp Pi is on the network I can also copy files that way too and fast.
All in all, a great budget option if all you need it USB storage.
If you have read the other reviews, then I can confirm some of the points. First, it’s not too bad. It’s decent value if you are on a budget. It’s pretty heavy, so it does sit rather nicely without flopping all over the place. It’s fairly quick to activate and operate. Pretty much just plug and play on Windows.
So now, for the bad. The body is metal but the back and front is plastic, and it’s not too bad. The drive bay door mechanism is flimsy plastic, which is disappointing. Since I do not plan on hot swapping drives all the time, this was not a huge issue for me. I would think that they would need to be replaced eventually if you are planning on opening and closing them on a daily basis.
The fans do get a little noisy as it ramps up. As mentioned in other reviews, they could have sourced quieter fans. I only have the device on when accessing data or backing up, so for me it’s not a huge issue. If you are going to run it during a live stream or gaming, then definitely look at a different device.
Last little issue is that when you turn it on, all the drives inside switch on. It would have been nice to have individual switches, but as I said, this device is okay if you are on a budget. Eventually I will upgrade it, and it will be used as a back up only, and live in a cupboard.
I have a Mac Mini (Mid 2011) that sits in a corner working as a DVR, file and Plex server. I needed to add significant storage to it but external Thunderbolt 1 drives are rarer than hens teeth and USB2/FireWire 800 drives too slow.
I have a Kanex Thunderbolt-to-USB3-and-eSATA adapter <https://www.amazon.co.uk/gp/product/B00LOLBBQQ> I bought 2 years ago and abandoned its use after a cheap 2.5″ external enclosure I had tested with it kept freezing and locking up the Mac so I was worried the TerraMaster would behave the same way. However, the TerraMaster wasn’t too expensive and, if it didn’t work with the Kanex, I had another use for it in which it should definitely work so wouldn’t be wasting any money.
On arrival I set the TerraMaster up (simple), put a 12TB 3.5″ drive in, connected to the Kanex and switched on. There were some odd errors in Disk Utility when I first formatted the drive but I wasn’t able to reproduce these on several subsequent re-formats. I then used SuperDuper to mirror the internal 1TB drive to the TerraMaster ( the test that the cheapo 2.5 inch enclosure had spectacularly failed). No problem – the clone was successful and showed speeds up to the USB 3.0 maximum of 5Gb/sec.
Since then I have repeated the test clone, smart-updates of the clone and even installed macOS to it – all with no disk problems. The only issue I encountered – which may be important to some people was that I could not boot off it when MacOS was installed – wouldn’t show up in the start-up disk chooser – and even if selected in System Preferences -> Startup Disk wasn’t found at boot so the Mac fell back to it’s internal drive. I imagine the EFI boot system doesn’t have USB 3 drivers on this model of Mac.
Overall the build quality is decent for the price. Unlike one reviewer I haven’t had any fan noise issues – haven’t even noticed any. However, I only have one disk installed so far and haven’t been stressing the system with continual heavy I/O.
Note for anyone else wanting to take this approach. The Kanex I reference above is no longer available but I imagine that either of these two Thunderbolt-1/2-to-USB3-and-Ethernet adapters would work the same: <https://www.amazon.co.uk/Thunderbolt-Gigabit-Ethernet-Kanex-KTU20/dp/B01F5LD97Ohttps://www.amazon.co.uk/Thunderbolt-Gigabit-Ethernet-Kanex-KTU20/dp/B01F5LD97O> or <https://www.amazon.co.uk/StarTech-com-TB2USB3GE-Thunderbolt-Gigabit-Ethernet-Silver/dp/B00PY194CK>.
I found the following info almost impossible to find before I bought this. I hope it’s of value to somebody.
I’m using a 2018 Mac mini. It has an internal SSD that has the OS and Apps but it’s too small and I needed an external drive for my files and Time Machine volume.
I have 2 SATA drives (not SSD’s) inside the Terra Master. The included USB to USB-C type connector worked a treat. I’m getting around 180MB/S reported on both SATA drives using Black Magic Disk Speed Test app (which was the same as inside a previous Mac Pro). This equates to a sustained 90mb per second when copying files from the hard drive of the Mac mini to the Terra Master.
I’m not using video but do a lot of work in Photoshop. Opening up, working on and saving a 500mb Photoshop file works fine. Very occasionally there will be a time lag of about a second or so when saving a large file but it’s absolutely fine. Unnoticeable to be honest. It would obviously be a lot faster with SSD’s inside but 2 4TB SSD’s would cost a fortune compared to what I paid for spinning disk drives. Unless you’re doing video I would say SATA drives are fine with this.
When I put the Mac to sleep the drives power down shortly after. There are no wake-up issues at all. Everything just works.
Also, one other thing I read was someone saying that when you put a drive in it forces you to format it. This alarmed me as I didn’t want my existing work wiped from the drive. I couldn’t easily find a guarantee that this wouldn’t happen. Don’t worry though. I put a disk in and it instantly recognised it and my files were all there. When I put a brand new drive in to be used with Time Machine is was exactly as normal and Disk Utility was able to format it. Incidentally, I used a Western Digital Blue 4TB 5400rpm drive for Time Machine and it copies files at the same speed at my 7200 Toshiba drive.
The thing runs quietly though disk accessing can be a bit loud (then it always is on any Mac or PC I’ve used).
Sorry for rattling on. I hope this info is useful to someone.