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Update 2: On further investigation, I have reproduced the issue on my windows side. I put the laptop on the dock while in sleep mode and woke it to find it climbing to 100% cpu usage. removing from the dock lets the cpu go down to ~5%. Replacing it on the dock causes 100% usage again. Note: The System Idle process uses relatively little cpu during this time.

Update: I just tried replicating this issue again on my windows side, and doesn't seem to be happening anymore. However, when im running ubuntu it becomes extremely slow. So this could actually be a driver issue with my ubuntu side.

The Problem:

I'm using a Dell e5430 laptop (provided by my employer) and have a docking station for it. When I use the docking station my cpu usage goes up to 100% and stays there.

What I've looked at:

-Task Manager: This cannot be traced to any particular process or service.

-Windows drivers: This also occurs when I boot into my ubuntu partition, so its a firmware/bios problem not related to a particular OS.

-Updates from dell: I checked their drivers page and did not see any updates relevant to my problem.

Other notes:

-This occurs whether or not I have any peripherals plugged in. I have tried plugging in and unplugging various things and it stays at 100% cpu usage even without anything other than the power cable.

Hennes
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Tacitus
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  • Which version of Windows? Also, make sure to show all processes in Task Manager. – Steven May 06 '15 at 20:21
  • Main OS is windows 7 professional. I checked all processes, nothing. – Tacitus May 06 '15 at 20:23
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    On the processes tab, did you click the "Show processes from all users" button? Then click on the CPU column header to sort by CPU usage. – Steven May 06 '15 at 20:28
  • So while this is happening Task Manager reports nothing using CPU cycles? What does it report for the System Idle process? Are you viewing tasks for all users? – Ƭᴇcʜιᴇ007 May 06 '15 at 20:28
  • Does that also happen when you boot with the laptop in the docking? (My E6500 often used 100% CPU after hot [un]plugging it from the dock. Both with XP and with win7) – Hennes May 06 '15 at 20:36
  • Edit: Sorry It uses windows 7 enterprise not professional. – Tacitus May 06 '15 at 20:38
  • I have seen this behavior on windows with a bad power adapter. – Tony Hinkle May 06 '15 at 22:09
  • Did the issue you saw occur when you used the power with laptop and not the dock? I use the same power adapter to plug into my laptop when I don't have the dock and this issue does not occur, so I think my power adapter should be fine – Tacitus May 07 '15 at 16:01
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    capture a xperf trace of the high CPU usage and share it: http://pastebin.com/pgE11HRD (The Win8 SDK/WPT also works on Windows 7) – magicandre1981 May 07 '15 at 17:27
  • here's a dropbox link: https://www.dropbox.com/s/fh8ydacw3nx7pa5/L035909.05-07-2015.11-54-14.etl.zip?dl=0 --- I'll be deleting this after a few hours – Tacitus May 07 '15 at 19:06
  • I can't see anything useful. There are so many tools running which consume a bit CPU and this sums up to 75% CPU usage. The dock seams to provide power and charges the laptop which causes Windows to change the powerplan, maybe the tools detect this and no do some work which they haven't one when you where using the battery. – magicandre1981 May 08 '15 at 04:16

1 Answers1

2

I figured out a small work around - I can use the dock as long as I don't plug in the power adapter. I plug the power adapter into the laptop itself and can use the dock without issues.

Tacitus
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