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 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.
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2. | Click Start, right-click Computer, and then click Manage.
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3. | Expand System Tools, Reliability And Performance, Monitoring Tools, and then click Performance Monitor.
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4. | On the Performance Monitor toolbar, click the green Add button.
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5. | On
the Add Counters dialog, 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
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6. | Click OK to add the counters to Performance Monitor.
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Now,
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 enablehighlighting.
Now,
click the first counter in the list. Once 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
Vista can automatically recover from many USB errors without impacting
the user.
If
you are troubleshooting USB performance problems, examine the Bulk
Bytes/Sec counters 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.
How to Examine USB Hubs
Connecting a USB device to a computer can include several different layers:
A
USB host controller, which is connected directly to your computer. USB
host controllers are often built into the computer’s motherboard, but
you can add them by using an internal adapter or a PC card. If the name
of the controller includes the word “Enhanced,” the controller supports
USB 2.0.
A USB root hub, which is
connected directly to the USB host controller. Typically, USB root hubs
are built into the same device that contains the USB host
controller—your computer’s motherboard or an adapter card.
Optionally,
additional USB hubs that connect to the USB root hub to create
additional USB ports. USB hubs can be external devices that you add,
they can be an internal device within a computer, or they can be built
into a docking station.
You can
use device manager to examine the USB controllers and hubs in a
computer, determine their power capabilities, and examine the power
requirements of the connected devices. This can help you to identify
the source of a USB problem. To examine USB devices, follow these steps:
1. | Click Start, right-click Computer, and then click Manage.
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2. | In the Computer Management console, click Device Manager (under System Tools).
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3. | In the right pane, expand Universal Serial Bus Controllers.
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4. | Right-click an instance of USB Root Hub (there might be several), and then click Properties.
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5. | Click the Power tab, as shown in Figure 1. This tab displays the power capabilities of the hub and the power requirements of every connected device. To determine the requirements of any specific device, disconnect other devices, and connect the devices one by one.
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