Quick tech specs
  • USB 3.0 eSATA Dual 3.5” SATA III Hard Drive External RAID Enclosure w/ UASP and Fan
  • Compatible with SATA revision I/II/III (1.5/3.0/6.0 Gbps)
  • UASP
  • Black
  • Black
  • HDD RAID Enclosure
  • 80 mm Ball Bearing Fan
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Know your gear

Create an external dual 3.5in HDD SATA RAID array, connected through either USB 3.0 with UASP or eSATA. The S3520BU33ER 2-Bay RAID Enclosure offers a high-performance external storage solution, enabling you to build a secure RAID array with two 3.5" SATA hard drives, with the option to connect it to your computer through either an available USB 3.0 or eSATA port.

For fast data transfers and efficient performance from your SATA III drives, the RAID enclosure supports full SATA III transfer speeds (up to 6 Gbps), as well as full USB 3.0 transfer speeds (up to 5Gbps). When connected through USB, the enclosure supports UASP, which offers performance up to 70% faster than conventional USB 3.0 when paired with a UASP-enabled host controller.

With support for JBOD, Spanning, RAID 0, and RAID 1, the enclosure offers several options that enable you to customize your drive arrangement based on your storage requirements.

To maximize both durability and reliability, the external RAID enclosure features high-quality aluminum construction with a built-in fan that helps improve ventilation and maintain a better operating environment for your drives.

The HDD enclosure offers a versatile solution for increasing the storage/backup capabilities of your computer, with support for large capacity hard drives (tested up to 4TB).

To ensure compatibility with your computer system, the S3520BU33ER supports all of the leading operating systems, including: Microsoft Windows (8/7/Vista/XP/Server 2008/Server 2003), Apple OSX (10.9/10.8/10.7/10.6), Linux, and Google Chrome OS.

UASP is supported in Windows 8, Mac OSX (10.8 or above), and Linux. In testing UASP performs with a 70% faster read speed and 40% faster write speed over traditional USB 3.0 at peak performance.

At the same peak in testing UASP also shows an 80% reduction in required processor resources.

Testing results were obtained using an Intel Ivy Bridge system, a UASP enabled Enclosure, and a SATA III solid state drive.

This item was discontinued on May 04, 2020

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Current Item USB 3 eSATA Dual 3.5” SATA III HDD RAID Enclosure UASP - Black

This Item: USB 3 eSATA Dual 3.5” SATA III HDD RAID Enclosure UASP - Black


Total Price: USB 3 eSATA Dual 3.5” SATA III HDD RAID Enclosure UASP - Black is rated3.50 out of5 by2.
Rated 5 out of 5 by from Not WorkingI bought this enclosure to had 2 internal drive after I downsized my case on the plus size it was very easy to fit the drives, Once booted up {and set To Jbod} my computer sees the drives in device manager but nothing is happening they don't appear in file manger or even in disk manager
Date published: 2018-09-25T00:00:00-04:00
Rated 5 out of 5 by from Great simple storageI’ve had a few of these kinds of desktop storage devices over the years, they are usually big, heavy and cumbersome. This unit is none of those. It’s not much bigger than two 3.5in drives stacked on top of each other, the drives just slide in from the front without a carrier, and setting up the RAID is done by sliding a switch on the back and holding the “Set Raid” button while turning it on. Simple!The unit is only as noisy as the HDDs you put into it. There is a small fan inside that you can hear when there aren’t any drives in it, but once you load it you can’t hear it at all. I like the look of the unit with the LEDs on the front showing power and activity, and I tried several large file transfers which were fast as I needed them to be with USB3. Nice to have the ESATA but I haven’t tried it yet. Build quality is good, with large rubber feet to minimize vibrations. For the List price, I think this unit provides good value for what it does.I received this product in exchange for an unbiased review
Date published: 2018-08-15T00:00:00-04:00
Rated 5 out of 5 by from Good speed when it's not disconnectingSeemed to work well but disconnects from the computer (Windows 10) once a day or more (and you then need to power cycle it to reconnect). Finally one of my drives was reporting errors so I tried moving data to another drive on the computer itself. It was a 6GB drive and the during the transfer it kept disconnecting until I finally got fed up and removed the drive from the enclosure. Put it in a different brand enclosure and the transfer is going well now. I may try to upgrade the firmware, but the download doesn't have any details about what's been fixed, and basically I don't trust this enclosure anymore.
Date published: 2017-09-14T00:00:00-04:00
Rated 5 out of 5 by from BuggyI am using JBOD, not RAID. With the USB cable Win10 will recognize and write to both of the HDD that I have in this enclosure (4TB and 6TB). However, the unit will shut itself off after a period of inactivity, so large copy operations should be monitored in case a file being open will pause the copy operation (e.g. Outlook .pst file if email client is open). I read in a review that this doesn't happen with the eSATA cable, however, with eSATA Win10 will only recognize one of the two drives I have installed. Enclosure has great potential but falls short.
Date published: 2018-05-17T00:00:00-04:00
Rated 5 out of 5 by from Noisier than expectedI am happy with the ease of setup and the overall functionality however the fan is extremely loud for the size of the unit. The enclosure is very light weight even with both drive bays filled, however the drives don't feel very securely mounted and may be contributing to the overall noise. Not my favourite product but it certain performs as expected if you can overlook the noise issue. I received this product in exchange for an unbiased review.
Date published: 2018-08-17T00:00:00-04:00
Rated 5 out of 5 by from Good.I used this with RAID and eSata connection with Windows 10. I did not experience the problems referenced in other reviews. I did notice that it was a bit loud for my quiet office.
Date published: 2018-08-15T00:00:00-04:00
Rated 5 out of 5 by from Needs work to be a contenderThis product is not what I would call one of's better products. The unit I received has a very very loud fan. Now I am not sure how loud this is supposed to be but I find the noise excessive. Drives install easy enough but they do not screw in, lock down or any type of security. The drives rattle a bit when you move the unit. I think some of the noise i hear is vibration from the drives! I dont think this will be good for the drives long term.The setup was easy, I tried using the combine feature and it worked without a hitch. Just move the switch to the drive setting you want, Hold in the set button and turn it on. Voila.I then formatted the drive for use with Apple and again no issues at all. I have viewed other comments about disconnects but I have not experienced this under OSX.The device works...the build quality is almost there..but the noise from fans, vibrations, is just too much.I received this product in exchange for an unbiased review.
Date published: 2018-08-06T00:00:00-04:00
Rated 5 out of 5 by from Compact, speedy, and easy to use.Undo one screw to access the insides. Press one button to change the RAID settings. It's THAT easy to use. Comes with both types of data cables, which I tried out and work just fine. Also used a USB-C to eSATA cable from Startech, and throughput to the box was just as it should be. Strangely I need to comment on how happy I am about the power brick. The AC side is a simple 2-prong cable instead of a big brick, so no fighting for power-strip/outlet space! The DC side cable is a really decent length too. The overall size of this device means it can be on the desktop yet out of the way, or you can easily place it on top of a tower PC out of the way. So using this with my newer XPS tower (which SUCK for only having internal bays), I've got tons more storage I can switch around, or even boot into. :)The only two critiques I have are:1. Fan is a bit noisy for such a small thing.2. I'd like to see some plastic 3.5 to 2.5 adapters included. Just my own two cents there. I used the box with 3.5" drives and tried all the modes and it was great. Then I had to fabricate my own drive adapters to use SSDs in a more permanent use case. With so many SSD options out there in the 2.5 size... including adapters by default would have put me over the edge to buy these for several uses!I received this product in exchange for an unbiased review.
Date published: 2018-08-27T00:00:00-04:00