How to determine whether a USB 3.0 device is operating at SuperSpeed?
Note: The information provided in this blog post applies to Windows 8.
Hi, I am Sanket Patel, a software developer on the USB team. In this blog post, I will describe some ways in which you can determine whether a USB 3.0 device that is attached to a PC running Windows 8 version of the operating system, is operating at the optimal connection speed - SuperSpeed.
USB 3.0 introduces a new operating speed called SuperSpeed. Compared to USB 2.0 bandwidth of 480 Mbps, SuperSpeed supports 5.0 Gbps making it 10 times faster than USB 2.0. USB 3.0 also supports lower operating speeds: high speed, full speed, and low speed. Along with increased bandwidth, USB 3.0 host controllers and devices come with the promise of compatibility. USB 3.0 controllers are required to work with all existing USB devices. The fact that current PCs ship with both USB 2.0 and USB 3.0 ports presents an interesting challenge: how should you determine whether a USB 3.0 device is indeed operating at SuperSpeed?
Here are some ways to determine the operating speed of the USB device:
Typically, newer PCs with USB 3.0 support have both USB 3.0 and USB 2.0 controllers, and both those ports are exposed. The receptacles on USB 3.0 ports are usually blue to distinguish from the receptacles on USB 2.0 ports, which are black. So, if the PC has a blue port, that is a good indication of USB 3.0 support. Note this is not a requirement of the official USB specification, rather a convention adopted by some PC makers.
Figure 1 shows a typical USB 2.0 port.
Figure 1. USB 2.0 port with a black receptacle
Figure 2 shows a typical USB 3.0 port.
Figure 2. USB 3.0 port with a blue receptacle
If the PC does not use blue receptacle for the USB 3.0 ports, it might have a USB 3.0 logo ( ) next to the port.
Figure 3 shows the USB 2.0 logo.
Figure 3. USB 2.0 logo
Figure 4 shows the USB 3.0 logo.
Figure 4. USB 3.0 logo
Figure 5 USB 3.0 logo on USB 3.0 cableView device information in Device Manager
Next, confirm that Windows enumerated the host controller as a USB 3.0 controller. To confirm that, open Device Manager and locate the controller under the Universal Serial Bus controllers node. If Windows recognized it as a USB 3.0 controller, USB 3.0 eXtensible Host Controller is appended to the device description as shown in Figure 6.
Figure 6. USB 3.0 eXtensible Host Controller in Device ManagerLook for Windows 8 UI messages to determine whether the USB 3.0 device is operating at SuperSpeed
To indicate whether the USB 3.0 device is operating at SuperSpeed, Windows 8 shows UI messages in specific places. If the PC has USB 3.0 controller to which a USB 3.0 device is attached, Windows 8 shows Connected to USB 3.0 when the device is operating at SuperSpeed. If the operating speed is lower than SuperSpeed, the message is Device can perform faster when connected to USB 3.0 .
You can view those UI messages in PC Settings.
Figure 7 shows the UI message when the USB 3.0 device is operating at SuperSpeed.
Figure 7. PC settings – UI message for a USB 3.0 device that is operating at SuperSpeed
Figure 8 shows the UI message when the USB device is operating at a bus speed that is lower than SuperSpeed.
Figure 8. PC settings – UI message for a USB 3.0 device that is operating at a speed lower than SuperSpeed
You can view similar messages in Devices and Printers , as shown in figures 9 and 10.
Figure 9. Devices and Printers - UI message for a USB 3.0 device that is operating at SuperSpeed
Figure 10. Devices and Printers – UI message for a USB 3.0 device that is operating at a speed lower than SuperSpeed
If the USB 3.0 device is a storage device, Windows Explorer shows similar messages when the volume label is selected, as shown in figures 11 and 12. Note that the View -> Details pane must be selected for the message to be visible.
Figure 11. Windows Explorer - message for a USB 3.0 device that is operating at SuperSpeed
Figure 12. Windows Explorer - UI message for a USB 3.0 device that is operating at a speed lower than SuperSpeedUse USBView to view device information about the bus speed
If you are writing a device driver, the USBView tool might be more useful for verifying the bus speed. The tool is included in the Windows Driver Kit (WDK) 8 Release Preview (RP), which is available for download at this Web site . USBView in this release has been updated to display SuperSpeed information.
Figure 13 shows a USB 3.0 device operating at SuperSpeed in USBView.
Figure 13. USBView – Message for a USB 3.0 device that is operating at SuperSpeedDetermine the bus speed programmatically Troubleshooting
Here are a few things to try if you find that your USB 3.0 device is capable of operating at SuperSpeed but is operating a lower bus speed:
Figure 14 shows a non-functional hub in Device Manager.
Figure 14. SuperSpeed USB Hub is not functional
In this blog post, we discussed ways of making sure that you get optimal experience with your USB 3.0 device attached to a USB 3.0 controller on a PC. If you have any questions, please leave us a comment.
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