COVID-19 Update: We are experiencing high demand. Processing time may be longer than usual. Learn More >

StarTech Dual Bay USB 3.0/eSATA RAID Enclosure for 2x 3.5" SATA HDD with UASP
SKU# AB69066, Model# S3520BU33ER

Pay Now, or Pay in 4 paypal
4 payments available with afterpay
Own it now, pay later

Customers also bought

Customers also viewed

SKU # AB69066 | Model # S3520BU33ER

See an error? Click here and let us know

StarTech Dual Bay USB 3.0/eSATA RAID Enclosure for 2x 3.5" SATA HDD with UASP and Fan - Black - JBOD, Raid 0-1 - USB 3.0 - 5 Gbit/s - SATA III (6 Gbps) - S3520BU33ER

Manufacturer Warranty: 2 Years Limited Warranty
Manufacturer Contact Info:,
Rating: 3.2 stars - 12 reviews

Product Overview

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 (see our performance below).

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.

It is backed by a 2-year warranty and free lifetime technical support.

Improved Performance with UASP

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.

Product Specifications

Warranty Information


2 Years


Chipset ID


Compatible Drive Types (Type and Rate)


Drive Installation


Drive Size


Fan Bearing Type

Ball Bearing




1 - 80 mm




USB 3.0

Number of Drives


Number of internal 3.5 inch bays



Hot Swap Capability


Max Drive Capacity

Currently tested with up to 4TB 7200 RPM hard drive

Port Multiplier




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 III (6 Gbps)

UASP Support



Drive Connectors

SATA Data & Power Combo (7+15 pin) Receptacle

Host Connectors

eSATA (7 pin; Data) Female


USB 3.0 B (9 pin; SuperSpeed) Female


Microsoft WHQL Certified


OS Compatibility

OS independent; No software or drivers required


LED Indicators

1 - Enclosure Power LED


1 - Drive 1 Activity LED


1 - Drive 2 Activity LED


Center Tip Polarity


Input Voltage

100 ~ 240 AC

Output Current

3 A

Output Voltage

12 DC

Plug Type


Power Source

AC Adapter Included



20%RH ~ 80%RH

Operating Temperature

5°C to 35°C (41°F to 95°F)

Storage Temperature

-20°C to 50°C (-4°F to 122°F)

Physical Characteristics



Enclosure Type

Aluminum and Plastic

Product Height

3.3 in [85 mm]

Product Length

6.9 in [176 mm]

Product Weight

21.9 oz [620 g]

Product Width

4.4 in [113 mm]

Packaging Information

Shipping (Package) Weight

47.8 oz [1355 g]

What's in the Box

Included in Package

1 - USB 3.0/eSATA HDD RAID Enclosure


1 - eSATA Cable


1 - USB 3.0 Cable


1 - Universal Power Adapter (NA/EU/UK) or AU in Australia


1 - Rubber foot set


1 - Instruction Manual

SKU # AB69066 | Model # S3520BU33ER

See an error? Click here and let us know