USB port test [USB] |
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(Applicable to BurnInTest Pro version only) Tests the USB (Universal Serial Bus) communications ports connected to the PC. The USB devices that are connected can be viewed from the Test Preferences window. A USB port loop back plug is required to run this test. Up to 25 USB ports can be tested when used with the PassMark USB 2.0 Loopback plug. There are two versions of USB loopback plugs. The USB 2.0 loopback plug provides a wider range of test for USB 1.x and 2.0 (USB 2.0 supports rates up to 480Mb/sec). For backwards compatibility the USB 1.0 loopback plug supports a range of testing for USB 1.x (USB 1.x supports rates up to 12 Mb/sec). The PassMark USB 2.0 Loopback Plug can be purchased from the PassMark web site.
Using a PassMark USB 2.0 Loopback Plug and BurnInTest, it is possible to,
In addition, with the USB 2.0 loopback plug and BurnInTest, it is possible to test:
It is worth noting that with the USB 2.0 loopback plug and the PassMark USB2Test software it is possible to:
Using these plugs on a system that is functioning correctly, you can expect error free loopback transfer speeds of around:
To reach this level you need to have the USB test duty cycle set to 100%. Up to 25 PassMark USB 2.0 loopback plugs (requires V7.0 or later of the device driver) or 10 PassMark USB 1 loopback plugs can be simultaneously connected to a PC (providing that free USB ports are available on the PC or on a down stream hub). Note: If required, both USB1 and USB 2.0 loopback plugs can be used to test different USB ports simultaneously.
To use the plugs they must be correctly installed with their device driver. See the installation and users guide that is supplied with the plugs for more details. Additional information about the plugs is also available on the PassMark web site.
Each test cycle corresponds to:
The number of Operations (‘ops’) corresponds to the number of bytes sent and received. The duty cycle affects the time spent waiting between cycles.
Each plug also has its own serial number stored in EEPROM, on the plug, so it is possible to identify each plug when multiple plugs are connected. USB 2.0 loopback plugs are firmware controlled and upgradeable.
The USB test sends data to the USB loopback plug in:
Any differences between the data send and received is flagged as an error.
As the low level USB protocol has some ability to detect errors and re-transmit bad data it is important to pay attention to the transfer speed. A low transfer speed may be an indicator of an intermittent or partial hardware fault. With the USB 2.0 loopback plug an error LED will be lit when more than a defined number of recoverable bus errors occur (currently set to 4). (Note: The USB2Test software will report the number of recoverable bus errors per block). A lack of high quality cabling within or external to the PC is a typical cause of retransmission due to recoverable bus errors. The USB 2.0 loopback plug Error LED is reset at the start of each test if results are configured to be cleared:
USB test window The following information is displayed in the USB test window. USB Identity An indication of whether the USB port is connected to a USB1 or USB2.0 loopback plug is shown together with the maximum speed supported by the protocol currently supported by the USB port (e.g. 12Mb/s or 480Mb/s). The device number and the unique device serial number are then displayed. The device number is determined by the order in which plugs are connected and disconnected and is not linked to a physical USB socket on the PC. (Note that this is different from Serial and Parallel ports). The device serial number is collected during the USB device enumeration process and comes from the memory (EEPROM) in the plug itself. Bytes Sent The number of Kilobytes sent to the USB device. Bytes Rec. The number of Kilobytes received from the USB device. Throughput The number of Kilobits or Megabits of data received and transmitted in the last second. Ave. Throughput The average number of Kilobits or Megabits of data received and transmitted per second since the start of the test. Errors The number of errors that have occurred (i.e. Transmitted data does not match received data). |