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Q180 High CPU Usage and interrupt spikes when using wired ethernet

Question

I've noted an odd symptom with my IdeaCentre Q180.  It is showing CPU usage of at least 40% all the time in the Windows 7 Task Manager. Sysinternals Process Explorer show that this is due to over 25% of Hardware Interrupts happening all the time.

 

I was able to locate and fix the problem yesterday. The problem was in the Realtek ethernet drivers. I disabled the device from the control panel and interrupts went a way. After that I removed the existing driver and re-installed with the one available on Lenovo support site and now interrupts are gone and CPU utilization is 0% when the computer is not doing anything.

Answer

 

 

The symptom may not be the driver itself, but with the wake on lan feature.  Reinstalling the driver, or just toggling the settings often resolve the symptoms.  In testing at Lenovo, we found that disabling the wake on magic packet resolved the high cpu utilitization and that the feature could subsequently be re-enabled.  During test, we did not see the symptoms return.

  

When you disable the Wake on Magic packet you should notice the interrupts drop to almost nothing.

 

Next, restart the machine and check the interrupts again and see if they remained low.  If so, re-enable Wake on Magic Packet and check again to ensure the interrupts remain at normal levels.

 

 

Steps to disable Wake on Magic Packet


Go to Device Manager
Network Controllers
Right Click on the Ethernet Controller and go to Properties
Click on the Advanced Tab
Scroll down in the Properties Window and click on Wake on Magic Packet
You should see the Enabled option come up in the window next to Properties

Click to Disabled

 

 

Some users have reported that just disabling  "Allow this device to wake the computer" within the Power Management tab may be enough as well.

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