The D2-320 4-Bay USB 3.2 Gen 2 RAID 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 two SATA drive bays that can handle 2.5 or 3.5" hard drives and SSDs, the D2-320 delivers data transfers of up to 1075 MB/s and write speeds of up to 956 MB/s when equipped with two SSDs configured as RAID 0. 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. The D2-320 may be configured in RAID 0, 1, JBOD, or single using a switch on the back.

Each drive bay allows for user-friendly and tool-free installation. Plug-and-play connectivity means that no additional drivers are required for use, while an intelligent 80mm cooling fan operates based on system temperature, ensuring that the drives operate within their optimal range.

Please note that the D2-320 does not currently support individual drives larger than 22TB.

2 x 3.5/2.5" SATA Drive Bays    1 x USB-C 3.2 Gen 2 Port    RAID 0, 1, JBOD, and Single    Hardware Controller    Read Speeds up to 1075 MB/s    Write Speeds up to 956 MB/s    Intelligent 80mm Cooling Fan    Tool-Free Drive Installation    Thunderbolt 3 and 4 Compatible    Windows, Mac, and Linux Compatible

With the USB 3.2 Gen 2 protocol, the D2-320 provides a 10 Gb/s data transmission bandwidth, with the actual read/write speeds of up to 521 MB/s when two hard drives are installed and read speeds of up to 1075 MB/s when two SSDs are used in RAID 0.

The D2-320 supports up to two hard drives and a maximum drive capacity of 22TB (compatibility with larger hard drives has not yet been verified), providing users with up to 44TB of storage (2 x 22TB).

The D2-320 is compatible with various hard disks, such as 3.5 and 2.5" SATA hard disks, and 2.5" SATA SSDs. Please note that using incompatible drives may cause your device to become disconnected, with low transfer speeds and drive recognition failures. Before you purchase any drives, please be sure to check TerraMaster's drive compatibility list.

Supports multiple RAID modes: RAID 0, 1, JBOD, and Single Disk. Professionals can choose one or more according to their application scenarios.

The D2-320 features a tool-free hard drive tray design that allows for easy installation and removal of hard drives without the need for any tools. Furthermore, the D2-320 incorporates a push-lock design, which automatically locks the hard drive tray when you insert a drive, preventing it from falling out or disconnecting. As a result, installing a hard drive takes less than 10 seconds, making it convenient for users who frequently swap hard drives to exchange data.

The D2-320 is equipped with a USB-C interface and a 3.3' USB-C to USB-C cable. It may also be used with a variety of computer interfaces, including Thunderbolt 4, Thunderbolt 3, and USB 3.2 Gen 1 (3.1 Gen 1 / 3.0).

The D2-320 can be connected to the USB interface of a TerraMaster NAS after special adaptation and adjustment. Creating arrays and storage pools on D2-320 with TerraMaster TOS could expand the storage space of your NAS.

Note: This function works only on TerraMaster NAS running TOS 5.1 or above.

The D2-320 supports sleep functionality, which can follow the computer OS to sleep, effectively reducing the working duration, and power consumption of the hard disk and extending its service life.

To prevent equipment and drives from being damaged by use of an improper power supply, the D2-320 adopts power supply protection. In the case of an improperly connected power supply, the device will enable automatic protection to prevent itself and the hard disk from damage.

The D2-320 adopts an intelligent temperature controlled and low-noise fan that adjusts its speed automatically based on the temperature of the hard disk to ensure it works at an optimal operating temperature. Furthermore, the internal structure of the device is specially optimized, which not only effectively increases the internal air pressure and reduces the working temperature of the hard disk, but also greatly reduces the resonance between device components and the hard disk. With this feature, the D2-320 can maintain satisfactory low noise, even under a full-load working environment.

Related Questions and Answers

Q: 1. Assuming the dip switches are configured properly, could I take 4 discs from bit older QNAP NAS and load the external drive enclosure with those drives and not have the drives reformatted?

A: Yes it can be done. Please check this site before proceeding to confirm your two units: https://www.qnap.com/en-us/nas-migration/

Q: 2. Can I use 4 different/Same HDDs' without any RAID Formation? Will they show up in windows explorer? what is the largest volume(size in TB) of a single HDD is supported in any of these 4 trays?

A: Currently each bay can support a 14TB disk. You do not have to set this up as a RAID. If you set this up as JBOD, each drive will be read as its own individual volume and you can use different size drives. Please be sure to check Qnap's website for compatible drives.

Q: 3. If I connect this to my existing QNAP TS-431K which is powered by an APC UPS, will the TS-431K signal the TR-004 to power down when street power is lost?

A: You will need to connect it also to the UPS.

Q: 4. With RAID used with DIP switches, can you still read individual hard drive S.M.A.R.T. info?

A: Most do not allow this. This one has not been tested.

Q: 5. Can this be used as a local backup for a larger QNAP NAS (TVS-872xt)?

A: Yes, as per the manufacturer the TR-004 would be compatible for expansion as a local back up with the TVS-872XT.

Q: 6. With 16TB and 18TB drives now on or coming to market, will 4 of these work in this enclosure?

A: At the time of this message, the QNAP TR-004 4-Bay USB 3.0 RAID Expansion Enclosure BH #QNTR004US supports up to 16TB drives. Unless something drastically changes with 18TB drives, they should work but I couldn't guarantee it until QNAP has tested them and adds them to the drive validation list.

Q: 7. Can I buy addition trays from B & H?

A: Yes, BH sells the addition trays for the QNAP TR-004 4-Bay USB 3.2 Gen 1 RAID Expansion Enclosure. This is the link. https://bhpho.to/2NoVwor

Q: 8. Can I use 4 drives together, 3 drives for RAID 5 and one drive for a backup?

A: The storage pools on the QNAP TR-004 4-Bay USB 3.2 Gen 1 RAID Expansion Enclosure can be configured any way you need.

Q: 9. Do you need to insert 4 drives off the bat, Or can you start with let's say 2? And if you can start with 2, do have to add 2 more at the same time, or can you add a 3rd, and then wait a while(like a year) and then add a 4th?

A: The QNAP TR-004 4-Bay USB 3.0 RAID Expansion Enclosure BH #QNTR004US allows you to start with 1 or more drives. Hardware raid will require you to erase everything when new drives are inserted if you want them to be part of the same RAID.

Q: 10. With 16TB, 18TB and even larger drives on or coming, will this enclosure work with 4 of them? Is there a limit to the individual drive size?

A: This unit will accept all 2.5 " and 3.5" hard drives regardless of capacity.Currently, QNAP lists two 16 TB drives (Seagate ST16000NE000 and ST16000VN001) as the maximum capacity compatible with this unit .