4 Bay External Hard Drive Array RAID Tower – eSATA USB 3.0 Enclosure

Turn 4 SATA hard drives into external RAID storage, connected through USB 3.0 or eSATA

Product ID: SAT3540U3ER

3,6 stars (7 reviews) |
  • SuperSpeed USB 3.0 host interface, with transfer rates up to 5 Gbps
  • SATA revision 2 compliant eSATA host interface, supporting transfer rates up to 3.0Gbps
  • Supported RAID modes: 0 (stripe), 1 (mirror), 3 (parity disk), 5 (striped parity), 10 (1+0), Span/Concatenation

The SAT3540U3ER 4-Drive USB 3.0/eSATA to 3.5" SATA RAID Enclosure is a high-performance external RAID storage solution that supports up to 4 high capacity (tested with up to 4TB per bay) 3.5-inch SATA hard drives over a USB 3.0 or eSATA connection.

The 4-bay RAID enclosure can be connected to the host/source computer through USB or eSATA and automatically builds your SATA RAID array based on your selection (Spanning, RAID 0, RAID 1, RAID 1+0, RAID 3, and RAID 5 supported), delivering a simple, yet flexible external storage solution.

Designed for convenience, the enclosure features front panel LED indicators that provide RAID information and simple hard drive status and activity monitoring. The enclosure also features a built-in, 3-speed 80mm fan with automatic or manual controls that enable you to customize the speed of the fan as necessary to ensure suitable operating temperatures for optimized drive performance.


  • Add external RAID storage without worrying about driver or software support
  • Maximizing the transferability of storage between different computer systems
  • Large volume external storage with redundancy for backups or archiving important data
  • Video editing or photography professional/enthusiasts working with very large file sizes

The StarTech.com Advantage

  • Support for up to 4 drives provide large amounts of storage with a choice of high speed interfaces from USB 3.0 or eSATA
  • The removable front cover and accessible drive bays allows drives to be replaced easily in case of failure or a system upgrade
  • Built-in support for numerous RAID modes for most personal/business needs and an 80mm controllable cooling fan to keep drives from overheating

Partner Numbers

  • UPC 065030846424


  • OS Independent logo
OS independent; No software or drivers required


Warranty Information Warranty 2 Years
Connector(s) Drive Connectors 4 - SATA Data & Power Combo (7+15 pin)
Host Connectors 1 - eSATA (7 pin, Data)
1 - USB Type-B (9 pin) USB 3.0
Environmental Operating Temperature 0°C to 40°C (32°F to 104°F)
Storage Temperature -20°C to 60°C (-4°F to 140°F)
Humidity 5% ~ 95% RH
Hardware Interface USB 3.0
USB 3.0 & eSATA
Front Door Key Lock No
Number of Drives 4
Drive Size 3.5in
Compatible Drive Types SATA
Drive Installation Removable
Fan(s) Yes
Fans 1 - 80 mm
Fan Bearing Type Ball Bearing
Chipset ID JMicron - JMB394
JMicron - JMB355
JMicron - JMS539
Indicators LED Indicators 2 - Host Connection Type
2 - Fan Mode
3 - Fan Speed
1 - Power
1 - RAID Rebuild
1 - HDD Error
6 - RAID Mode
Packaging Information Package Quantity 1
Package Length 29,3 cm [11,5 in]
Package Width 15,8 cm [6,2 in]
Package Height 272 mm [10,7 in]
Shipping (Package) Weight 2,8 kg [6,1 lb]
Performance Type and Rate USB 3.0 - 5 Gbit/s
UASP Support No
Type and Rate SATA II (3 Gbps)
Hardware Raid Supported Yes
Supported RAID Modes BIG (Spanning or Concatenation)
RAID 0 (Striped Disks)
RAID 1 (Mirrored Disks)
RAID 10 (1+0, Striped set of Mirrored Subset)
RAID 3 (Striped set with Dedicated Parity)
RAID 5 (Striped Disks with Parity)
Max Drive Capacity Currently tested with up to 4 TB 5400 RPM hard drives per bay (16TB total)
Fan RPM Low - 1200rpm
Med - 1800rpm
High - 2500rpm
Physical Characteristics Color Black
Material Aluminum and Plastic
Product Length 21,5 cm [8,5 in]
Product Width 126 mm [5,0 in]
Product Height 17 cm [6,7 in]
Weight of Product 1800 g [63,5 oz]
Power Power Source AC Adapter Included
Input Voltage 115V-230V AC
Input Current 1.6A
Output Voltage 12V DC
Output Current 5A
Plug Type 4-pin DIN
Software OS Compatibility OS independent; No software or drivers required
Special Notes / Requirements System and Cable Requirements Available USB or eSATA port
Note The maximum supported partition size for some 32-bit Windows systems is 2 TB. These versions of Windows cannot detect multiple drives in any RAID mode if the total size exceeds 2 TB.
What's in the Box Included in Package 1 - Four drive HDD enclosure
4 - Hard Drive Handle
1 - eSATA Cable
1 - USB 3.0 Cable
1 - Screw driver and screw kit
3 - Power Cord (NA/ UK/ EU)
1 - Universal Power Adapter
1 - Instruction Manual



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Frequently Asked Questions

How To

To confirm that the Mac OS detects your USB device, complete the following:

  1. Click the Apple icon.
  2. Click About This Mac.
  3. Click More Info or System Report.
  4. 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.


SATA hard drive controllers require a feature called port multiplier to read more than one hard drive per SATA or eSATA port. The port multiplier feature is not standard on many SATA hard drive controllers.

If your computer is only recognizing one of your hard drives, you need to plug the eSATA cable into a SATA controller that includes the port multiplier feature. If none of your current hard drive controllers include this feature, you can add a hard drive controller that does support port multiplier in any available expansion slot (for example, PCI, PCI-Express, PCMCIA, CardBus, or ExpressCard). StarTech.com has hard drive controllers available that support the port multiplier feature. To view the hard drive controllers, click here: http://startech.com/Cards-Adapters/HDD-Controllers/SATA-Cards/?filter_PORTMULTIPLIER=Yes.

If you have a hard drive controller card that does support the port multiplier feature but it is only reading one hard drive at a time, update the drivers of the hard drive controller. To find the most current StarTech.com drivers, click here: http://www.startech.com/Support.

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:

  • Cables
  • 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. To avoid lost data, you need to back up all of the data prior to setting a RAID mode.

To set up a RAID mode, complete the following:

  1. To prevent the hard drive enclosure from entering sleep mode, use a USB cable to connect the hard drive enclosure to a computer.
  2. Turn on the hard drive enclosure.
  3. Press and hold the Mode button until one of the RAID LEDs start to blink.
  4. To select the RAID mode of your choice, press the Mode button until the LED for the RAID mode that you want to set is blinking.
  5. Press and hold the Confirmation button on the back of the unit until the hard drive enclosure turns off.
  6. Turn on the hard drive enclosure.

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.
  1. Determine which drive is operational by using the RAID management utility (if available) or test each drive individually on a different hard drive controller (for example, a hard drive docking station or SATA controller).

  2. Replace the failed drive with an identical hard drive.

The array will rebuild and is accessible during the rebuilding process.

RAID 3 Single drive failure will rebuild.
  1. Determine which drive is defective by using the RAID management utility (if available) or with diagnosis LEDs on the controller or enclosure.

  2. Replace with an identical hard drive.

Note: Do not change the order of the drives.

  1. The array may be accessible during the rebuild, but you should let the controller rebuild without interruption so that performance is not compromised.

RAID 5 Single drive failure will rebuild.
  1. Determine which drive is defective by using the RAID management utility (if available) or with diagnosis LEDs on the controller or enclosure.

  2. Replace with an identical hard drive.

Note: Do not change the order of the drives.

  1. The array may be accessible during the rebuild, but you should let the controller rebuild without interruption so that performance is not compromised.

RAID 10 Only one drive in a mirrored set can fail.
  1. Determine which drive is defective by using the RAID management utility (if available) or with diagnosis LEDs on the controller or enclosure.

  2. Replace with an identical hard drive.

Note: Do not change the order of the drives.

  1. The array may be accessible during the rebuild, but you should let the controller rebuild without interruption so that performance is not compromised.


You should not upgrade your device's firmware if you do not have any issues with the functionality of your device. The only time you should consider an upgrade is if you are experiencing a problem with the device, and you have confirmed that the firmware addresses this problem.  You can confirm this is the case by reviewing the documentation included with the firmware or by consulting with our Technical Support team. Incorrectly upgrading firmware can result in diminished performance so it is best to contact StarTech.com if you would like to perform this operation.

Before You Buy

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 mode Description Operation Advantages Disadvantages Recovery
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.

No redundancy.

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.


Compliance and safety

Compliance letters

Safety Measures

  • If product has an exposed circuit board, do not touch the product under power.
  • If Class 1 Laser Product. Laser radiation is present when the system is open.
  • Wiring terminations should not be made with the product and/or electric lines under power.
  • Product installation and/or mounting should be completed by a certified professional as per the local safety and building code guidelines.
  • Cables (including power and charging cables) should be placed and routed to avoid creating electric, tripping or safety hazards.
*Product appearance and specifications are subject to change without notice.

Customer Reviews

(7 reviews)
3,6 out of 5 stars
  • 5 (3)
  • 4 (2)
  • 3 (0)
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1 - 7 of 7 Reviews
(5 Stars)

Small Business Workhorse

By: Ronnie - 02/09/2014
I don't know what the actual rating on this is for run time or MTBF, however I've had it on for about six months non stop being accessed constantly by about five users during day and running bulk backups over night. This thing is a solid workhorse for my small business running quad 4TB in RAID 5 over eSATA. USB3.0 is okay at burst transfers however this is not the fault of the enclosure, but rather the real world shortcomings of USB in general. I'm guessing a UASP and/or Thunderbolt version will be in the works? Maybe a Six bay unit? I really don't want to have to buy something a pre loaded unit from someone else when I out grow this.
| Helpful?
David S., Customer Support on 19/02/2014 15:57:28
Sounds like you're putting your SAT3540U3ER through its paces! Glad to hear it's meeting your expectations.
(5 Stars)

Great product! I own 2!

By: BRUTEF0RCE - 02/10/2014
Excellent versatile product with the right price. I used to own an older version of this and was having all sorts of issues which at one point made me give up... But I risked to buy this product and it was a total satisfaction with no problem. So I decided to buy a second one with the same degree of satisfaction. I would recommend this specific product to any friend
| Helpful?
David S., Customer Support on 19/02/2014 15:57:08
Sorry to hear the older version didn't do so well for you, but it's great that your recent experiences with the SAT3540U3ER have been so positive. Thanks for letting us know.
(1 Stars)

No so much...

By: imadude - 02/20/2014
Usually a fan of Startech products but not so much for this one. Arrived with a defective power supply.. which i can overlook.. it happens. But overall quality of device is poor. Flip-down cover falls off continually when opening, drives do not fit into may with ease... requires repeat attempts, wiggles to get it in. Generally a poor (built) quality device. Does not inspire confidence which it should considering it is a semi-professional type of device.
| Helpful?
Barry W., Technical Support on 22/02/2014 19:00:11
Hello, we're sorry to hear that your experience has not been ideal with that enclosure. Generally we receive great feedback from our customers using it. Have you had the adapter replaced yet? If not, we would like to assist with that as well as hear more on the rest of the points you've made. Please call use at 1-800-265-1844 or [email protected]

By: JACKIE2 - 03/18/2014
make sure you connect power supply and esata or usb cable - otherwise unit goes offline
| Helpful?
(4 Stars)

Good value for the price.

By: da_rey64 - 03/10/2014
I bought this as I had 4-2TB drives collecting dust and thought it would make a nice simple backup drive for my home lab using VEEAM. The device itself is okay, for the price it's a great value, though the workmanship isn't great. The drives don't align very well with the connectors and the bottom drive is very difficult as there isn't any clearance to 'work it' into the slot (maybe it was my gorilla hands, but it was difficult). It took me longer to manipulate the drives to seat properly than it did to get everything else on it running. Over all I am happy with it. Simple to setup, pretty intuitive.
| Helpful?
(4 Stars)

works good - phone support great! not blazing fast

By: thecrs - 09/23/2014
getting about 125MB/s read /write on usb3 with 4 drives in span. have 2, 2 TB and 2 1.5 TB seagate drives - shows up as a 7th drive - used for my time machine
| Helpful?
(5 Stars)

Hard to Beat for the Price

By: Tim in VA - 10/20/2014
Though not "enterprise grade" compared to, say, big rack-mount disk enclosures, these are very spiffy units. Set us as RAID5 with four 1 Tb drives, these make very nice virtual-machine storage units. We've used them in our corporate environment for years, and none have failed yet. Does well with RedHat/Centos Linux, Windows servers. Keep the packing box - - it's nice if you want to travel with the unit.
| Helpful?
(1 Stars)

First bad HDD lite and now orange Power lite

By: Mcsweet - 09/26/2015
Ran this box for sometime 24/7 with no major problems and then I got a RED lite for a Bad HDD replace the drive still got the Red Lite replace all the drive same thing so I swith to another raid mode now all I have is a Orange Power lite ... the box is DEAD
| Helpful?
Customer Support, Customer Support on 15/10/2015 12:11:26
Hello, Thank you for taking the time to review our SAT3540U3ER. We are sorry to hear that the RAID has failed and we would like to offer some help. With the power LED being orange with no other LED’s lit up it sounds like the enclosure is currently in sleep mode. For the data that was on the RAID originally, do you have any back-ups available? After changing the RAID mode away from the original setting you had used the data will unfortunately wiped from the RAID enclosure. We recommend following the steps in our product manual on Page 5 to set up the enclosure again. Here is an article which can be found on the support page for this product which covers the process of setting the RAID mode: http://www.startech.com/faq/hard_drive_enclosures_sat3540u3er_raid_setup_change#SAT3540U3ER We are always here to help with our free lifetime technical support. If this did not resolve your issue, please get in touch with us and reference case #332-285886 so we can further assist you. You can also reply here and we will be sure to follow up. Thank You, Customer Support StarTech.com http://www.startech.com/support
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