USB 3.0/eSATA Dual 3.5” SATA III Hard Drive External RAID Enclosure w/ UASP and Fan – Black (S3520BU33ER)
Dual 3.5in USB 3.0 Hot Swap Trayless SATA Hard Drive Enclosure w/ Fan
Connect Two Removable SATA Hard Drives through a Single USB 3.0 Connection
Product ID: SAT3520U3R
- Trayless design: 3.5in drives are not mounted to a tray or the enclosure chassis/frame
- SuperSpeed USB 3.0 compliant host interface, which supports transfer rates up to 5 Gbps
- RAID support: 0, 1, BIG (Concatenation), JBOD
The SAT3520U3R USB 3.0 to Dual 3.5-inch SATA Trayless Hard Drive Enclosure makes adding fast external storage easy, by turning any two 3.5-inch internal SATA hard drives into an external hard drive. Large capacity drives (tested with up to 4TB per bay) can be used to greatly enhance your computer's storage/backup capabilities.
The hard drive enclosure features a trayless system that eliminates having to mount and fasten the hard drive into the enclosure or tray, for quick and easy installation or removal.
Using the SuperSpeed USB 3.0 interface, which is up to 10 times faster than the previous USB 2.0, makes backing up and transferring large files faster than ever, while still being usable on older USB 2.0 systems. With built-in RAID capabilities (0, 1, BIG, JBOD), the two drives can be combined for speed, redundancy, capacity, or even left as separate drives, based on situation needs.
The StarTech.com Advantage
- SuperSpeed USB 3.0 technology provides fast access for external storage, while still being backward compatible with USB 2.0
- Quickly and easily install or remove hard drives from the enclosure with the innovative trayless design
- Built-in support for RAID 0, 1, JBOD and Concatenation modes to suite most personal/business needs
Adding external storage that is easily transferable between different computer systems
Expand the storage capabilities of a small form factor/embedded system or laptop, with an external hard drive
Adding external storage capacity for video editing or photo editing stations, making it easier to work with very large file sizes
Creating additional backup/archive storage for IT professionals
Turning unused SATA hard drives into additional external data storage
|Chipset ID||JMicron - JMS551|
|Compatible Drive Types||SATA|
|Fans||1 - 55 mm|
|Number of Drives||2|
|Insertion Rating||15, 000 cycles|
|Max Drive Capacity||Currently tested with up to 4TB 5400 RPM hard drives per bay (8TB total)|
|Supported RAID Modes||BIG (Spanning or Concatenation)|
|JBOD - (Just a Bunch of Disks)|
|RAID 0 (Striped Disks)|
|RAID 1 (Mirrored Disks)|
|Type and Rate||USB 3.0 - 5 Gbit/s|
|SATA II (3 Gbps)|
|Drive Connectors||2 - SATA Data & Power Combo (7+15 pin) Receptacle|
|Host Connectors||1 - USB Type-B (9 pin) USB 3.0 Female|
|OS Compatibility||OS independent; No software or drivers required|
|Special Notes / Requirements|
|System and Cable Requirements||Available USB port|
|LED Indicators||2 - Activity (blue)|
|2 - Power (blue)|
|Input Voltage||110V-240V AC|
|Output Voltage||12 DC|
|Power Source||AC Adapter Included|
|Humidity||8% ~ 90% RH|
|Operating Temperature||5°C to 80°C (41°F to 176°F)|
|Storage Temperature||-40°C to 70°C (-40°F to 158°F)|
|Enclosure Type||Aluminum and Plastic|
|Product Height||135 mm [5.3 in]|
|Product Length||210 mm [8.3 in]|
|Product Weight||858 g [30.3 oz]|
|Product Width||76 mm [3 in]|
|Shipping (Package) Weight||1545 g [54.5 oz]|
|What's in the Box|
|Included in Package||1 - Hard Drive Enclosure|
|1 - USB 3.0 Cable|
|3 - Power Cord (NA/UK/EU)|
|1 - Universal Power Adapter|
|1 - Instruction Manual|
Add one internal and one external SuperSpeed USB 3.0 to your PC
Add two flushmount USB 3.0 ports to your ExpressCard-enabled laptop
Drivers & Downloads
Frequently Asked Questions
Before You Buy
To determine if your hard drive will work in this enclosure, on the product page, click the Technical Specifications tab, and do the following:
- Make sure that the enclosure supports the storage size of your hard drive. If the storage size of your hard drive is larger than what the enclosure was tested with, the hard drive will likely still work with the enclosure.
- Confirm that your hard drive uses the same interface type as the enclosure. For example, IDE, SATA, or M.2.
- Make sure that the enclosure supports the physical size of your hard drive, such as 2.5 inches or 3.5 inches.
- Make sure that the enclosure supports the height of your hard drive. For example, 9 mm or 15 mm.
- Verify that the power consumption of your hard drive doesn’t exceed the power output of the enclosure. If you’re using multiple hard drives, make sure that the combined power consumption of all of the hard drives doesn’t exceed the power output of the enclosure.
Note: Not all StarTech.com devices support each of the RAID modes described below. For more information on the RAID modes that your device supports, refer to the manual or the StarTech.com product page.
Redundant Array of Independent Disks (RAID) is a virtual disk technology that combines multiple physical drives into one unit. RAID can create redundancy, improve performance, or do both.
RAID should not be considered a replacement for backing up your data. If critical data is going onto a RAID array, it should be backed up to another physical drive or logical set of drives.
The following are terms that are normally used in connection with RAID:
- Striping: data is split between multiple disks.
- Mirroring: data is mirrored between multiple disks.
- Parity: also referred to as a checksum. Parity is a calculated value used to mathematically rebuild data.
Different RAID levels exist for different application requirements.
Refer to the following table for the list of RAID modes offered by some StarTech.com products:
|RAID 0||Striped disks||Data is split evenly between two or more disks.||Large size and the fastest speed.||No redundancy.||If one or more drives fails, this results in array failure.|
|RAID 1||Mirrored disks||Two or more drives have identical data on them.||A single drive failure will not result in data loss.||Speed and size is limited by the slowest and smallest disk.||Only one drive is needed for recovery.|
|RAID 3||Striped set with dedicated parity||Data is split evenly between two or more disks, plus a dedicated drive for parity storage.||High speeds for sequential read/write operations.||Poor performance for multiple simultaneous instructions.||A single drive failure will rebuild.|
|RAID 5||Striped disks with distributed parity||Data is split evenly between three or more disks. Parity is split between disks.||Large size, fast speed, and redundancy.||The total array size is reduced by parity.||A single drive failure will rebuild.|
|RAID 10||1+0; Striped set of Mirrored Subset||Four or more drives are made into two mirrors that are striped.||Larger size and higher speed than RAID-1, and more redundancy than RAID-0.||No parity.||Only one drive in a mirrored set can fail.|
|JBOD||Just a Bunch Of Disks||Any number of drives are accessed independently by the operating system.||Software RAID modes can be used.||Hardware RAID may have better performance.||N/A|
|Big||Spanning or Concatenation||Data is written on one drive until it is full, and then the next drive(s) until it or they are full.||Creates a very large and simple array.||
|Clone||RAID 1 + Spare||
Two drives have identical data, plus one drive is used for rebuilding in case of a primary array failure.
|Seamless operation when one drive fails in a RAID-1 array.||Spare drive is not accessible to the user.||Only one drive is needed for recovery.|
To confirm that the Mac OS detects your USB device, complete the following:
- Click the Apple icon.
- Click About This Mac.
- Click More Info or System Report.
- Under the appropriate heading, confirm that your USB device is listed and that there isn't an error. For example, a network card would be under Ethernet Cards.
You may need to refresh the System Information page after you plug in your device. To do so, press Command + R with the System Information page open.
Your USB device is listed according to the name of the chipset. To determine the name of the chipset of your USB device, navigate to www.StarTech.com and look on the Technical Specifications tab for your product.
When you troubleshoot issues with a hard drive enclosure, there are some quick tests that you can complete to rule out potential problems. You can test to make sure that the following components are working correctly and are not the source of the issue:
- Hard drives
- Hard drive enclosure
To test your setup components, try the following:
- Use the cables, hard drives, and hard drive enclosure in another setup to see if the problem is with the components or the setup.
- Use a different cable, hard drive, and hard drive enclosure in your setup to see if the problem persists. Ideally, you should test a component that you know works in another setup.
When you test the hard drive and hard drive enclosure, it is recommended that you do the following:
- To check Disk Management, press the Windows key + R, type diskmgmt.msc, and press Enter. Check to see if your hard drive is listed.
- If the hard drive is listed with unallocated space, the hard drive needs to be reformatted. Right-click unallocated and click New Simple Volume. Follow the on-screen instructions to complete the reformatting.
Note: Formatting a hard drive erases all of the data on it. Make sure that you back up all of your data before you reformat the hard drive.
- If the hard drive is listed as healthy but does not have a drive letter, for example, C:, right-click healthy and click Change Drive Letter and Paths. Click Add, assign a drive letter, and click OK.
Note: A formatted hard drive will not show up in Computer or My Computer until it has a drive letter assigned to it.
Note: Any data currently on the drives will be lost during this process. You need to back up all of your data before you set a RAID mode.
To set up a RAID mode, complete the following:
- Turn on the hard drive enclosure.
- Set the RAID switch to the RAID mode that you want to set.
- Press the RESET button.
In order to rebuild a RAID array, you need to replace a physical drive with an identical drive on the same RAID controller. Although standard RAID levels are generally agreed upon throughout the industry, the implementation varies between manufacturers. RAID arrays are typically not accessible when they are moved to another controller, and data may be unrecoverable if the drives are out of order or have been formatted or accessed by another RAID controller.
If a RAID controller has failed, you should get the exact same model of RAID controller.
Note: If a drive or drives were damaged, it is possible that the RAID array may be permanently unrecoverable.
RAID should not be considered a replacement for backing up your data. If critical data is going onto a RAID array, you should back up the data on another physical drive or logical set of drives.
Rebuild a RAID array
With the following RAID modes, recovery is possible using the same StarTech.com product. Refer to the following table for the appropriate method to use to recover your RAID array.
|RAID mode||Max # of failed drives||Procedure|
|RAID 1||Only one drive is needed for recovery.||
The array will rebuild and is accessible during the rebuilding process.
|RAID 3||Single drive failure will rebuild.||
Note: Do not change the order of the drives.
|RAID 5||Single drive failure will rebuild.||
Note: Do not change the order of the drives.
|RAID 10||Only one drive in a mirrored set can fail.||
Note: Do not change the order of the drives.
* Product appearance and specifications are subject to change without notice.