How to Identify USB Problems Using Performance Monitor

If you are concerned that you may have a USB bandwidth or performance problem, you can identify the problem by using the Performance snap-in:

1. If the problem you need to identify occurs when you are actively using a USB device, connect the USB device that you want to troubleshoot and turn it on. If the problem occurs when you first connect the USB device, do not connect the device until after you have begun logging.
2. Click Start, right-click Computer, and then select Manage.
3. Expand System Tools, Performance, Monitoring Tools, and then click Performance Monitor.
4. On the Performance Monitor toolbar, click the green Add button.
5. In the Add Counters dialog box, in the Available Counters group, expand USB. If you are troubleshooting the failure of a USB device, add the following counters for the <All Instances> instance:
   • Iso Packet Errors/Sec
   • Transfer Errors/Sec
   If you are troubleshooting a USB performance problem, add the following counters for the <All Instances> instance:
   • Bulk Bytes/Sec
   • Avg. Bytes/Transfer
6. Click OK to add the counters to Performance Monitor.

Performance Monitor begins collecting data about your USB devices and connections. Attempt to reproduce the problem (for example, by copying a file to a USB hard disk or connecting a video camera). If you are troubleshooting performance problems, right-click the Performance Monitor display and click Clear immediately after you begin using the device to ensure the counters include only data created during your test. The longer you allow the test to run, the more accurate it will be. You should stop Performance Monitor before your test ends.

After reproducing the problem, pause Performance Monitor by clicking the Freeze Display button on the toolbar or by pressing Ctrl+F. Because you added performance counters for all instances, you probably have a large number of counters. To browse individual counters to identify the specific source of your problems, press Ctrl+H to enable highlighting.

Click the first counter in the list. After you select a counter, the graph related to that counter will be shown in bold. Examine the values for that particular counter. If the counter shows an error, make note of the USB controller and device causing the problem. Press the down arrow on your keyboard to select the next counter and continue analyzing USB performance values.

USB errors should not occur under normal circumstances; however, Windows can automatically recover from many USB errors without affecting the user. After you identify the source of the USB problems, follow the steps in the section titled "How to Solve USB Driver and Hardware Problems" earlier in this tutorial.

If you are troubleshooting USB performance problems, examine the Bulk Bytes/Sec counter to identify the instance that relates to the device you are using. Then select the counter and make note of the Average value. Theoretically, USB 2.0 can transfer a maximum of 60,000,000 bytes/sec. However, this theoretical maximum will never be realized. More realistically, you might be able to achieve half that value. USB storage devices are often much slower, and performance will vary depending on the performance of the device itself. USB hard disks typically average less than 10,000,000 bytes/sec but can peak over 20,000,000 bytes/sec. Performance of hard disks will also vary depending on the portion of the disk being written to or read from, the size of the files being accessed, and the disk fragmentation.