PassMark Software

USB3.0 Loopback Plugs

High Quality Loopback Plugs for USB 3.0 Troubleshooting and Testing

USB 3.0 Loopback plugs are one of the fastest methods to diagnose, troubleshoot and load test your PC's USB functions.

When used with compatible PassMark testing software (see below) it is possible to:

  • Quickly check if a USB port is powered;
  • Measure the voltage of the USB port, no driver is required for this as the plug will display this information directly on the LCD screen (accurate to ±0.1V)
  • Check that data can be sent and received from the port;
  • Check USB errors rates and transmission speed (up to 5Gbits/sec ) in Windows;
  • Measure the level of recovered data (retransmitted frames);
  • Verify that the system remains stable under long periods of load;
  • Test that USB support in Windows or Linux is available;
  • Test self powered USB hubs and PC ports function correctly;
  • Check USB cabling;
  • Concurrently check multiple USB ports at the same time;
  • Perform USB port security audits;
  • Benchmark your PC's USB ports & hubs;
  • Check if your PC ports are super speed 5Gbits/sec (USB 3.0), high speed 480Mbits/sec (USB 2.0) or full speed 12Mbits/sec (USB 1.x); and
  • Can be used in conjunction with the USB Power Delivery Tester to test electrical load.
Quantity Price (USD) ORDERING
1 - 4 $120.00 Add to cart
5 - 10 $108.00
11 or more $96.00

These prices do not include shipping and do not include the BurnInTest Professional software. A USB3 cable is included in the price.

Active loopback plugs are the quickest, most effective way to verify that a PC's USB ports are working correctly. The Red, Green and Yellow LED's on the front of this USB adapter plug provide a quick visual indication of I/O activity and if the USB bus is powered. This will dramatically improve the troubleshooting and diagnostic ability of computer technicians and system integrators, who have previously been working blind.

In benchmark mode (Windows only), the device is capable of reaching the maximum defined transfer speed for USB3.0, 5Gbit/sec. Note: Testing has shown that most PC's can not attain speeds much above 3.5Gbits/sec and performance will vary depending on your motherboard, CPU and other USB devices connected to the PC.

Up to 10 of these USB test plugs can be simultaneously connected to a PC providing that free USB ports are available on the PC or on a down stream hub and sufficient power is available.

These plugs are unique! They are the only true USB 3.0 loop back adapters on the market and have been especially designed for use with our BurnInTest Professional, BurnIntest for Linux software package or USB3Test stand alone software (supplied with the plug). They do not require an external power supply and do not require a connection to any other port on a PC. Each plug also has its own serial number stored in EPROM, on the plug, so it is possible to identify each plug when multiple plugs are connected.

Each plug also contains its own CPU and executes its own firmware.

Size: 85mm x 45mm x 12mm (3.4 x 1.8 x 0.5 inches)
Weight: 40g (1.4oz)
Product Code: PM065

Video Demonstration

Technical Specifications

USB standard: 3.0 SuperSpeed, HighSpeed and FullSpeed
Note 1: USB3.0 is also now known as USB 3.1 Gen 1
Note 2: Plugs are also backwardly compatible with USB 2.0
Plug and play: Compliant
Physical connector: Standard 10 wire USB3 Micro B Receptacle (Female)
USB Transfer modes: Bulk and Isochronous
Voltage: 4.6V - 6.0V. (No external power supply is required)
Current: 75mA (Typical USB 2.0 operation), 90mA (Typical USB 3.0 operation)
Clock speed: 19.2Mhz
Device memory: 512KB
Case: High impact ABS plastic
Size: 85mm x 45mm x 12mm (3.4 x 1.8 x 0.5 inches)
Weight: 40g (1.4oz)
Indicators: Orange LED = Power from USB bus
Green LED = Transmit data
Yellow LED = Receive data
Red LED = USB bus transmission error indicator
EMC standards: AS/NZS 3548:1995, EC.
ESD immunity: See FAQ page
Storage Temperature: -30 ºC to 80 ºC
Usage Temperature: 0 ºC to 70ºC
Max speed: 5 Gbits/sec
Model number: PMUSB03 
RoHS (Lead free) : Yes

The specifications above are for the PassMark USB 3.0 Loopback plug hardware revision 2.


Each plug comes with a 33cm (13inch) USB3 Micro B (male) to USB3 A (male) cable.

Type C Compatibility
USB 3.0 Loopback plugs are compatible with our optional USB 3.1 Type C Cables.


Windows : Windows 7 and 8 (32bit & 64bit). Windows 10 (64bit only)
Linux: Most distributions with Libusb 1.0 installed will work. But software support is more limited. See below.

In order to use the plugs you also need at least one of the following 5 software applications.

USB 3.0, and 2.0 ports are supported. (when connected to a USB 2.0 port only the lower speed mode will be used)
Plugs will work with motherboard USB ports and hub connected USB ports.

Windows and Linux Application Programming Interface (API)

The free USB3 Application Programming Interface has been designed to allow access by 3rd party programs to the PassMark USB 3.0 loop back plug. It provides several functions to communicate with the USB3 loop back plugs as an easy way to use the plugs without having to write any device driver or extra firmware code. For more information, please see this page.

Current special