CPU running continuously at 90% on one core

Discussion in 'Windows 64bit' started by Lorne, Jul 6, 2010.

  1. Lorne

    Lorne Guest

    I have Windows 7 home premium running on an AMD X6-1055 6 core processor.
    If I start Windows and leave it doing nothing except the background
    processes loaded at boot time the CPU runs continuously at 14/15%.

    When I inspect task manager it tells me system idle process is 99%, and none
    of the 80 running processes register above 0%, but at the bottom CPU use is
    still 14%+.

    When I look at the performance tab one processor (always the same one) is
    running at 85-90% and the others near zero.

    When I use a motherboard utility it shows the same thing - one processor at
    85%+ and the others near zero.

    How do I find out what is running to cause this when task manager does not
    show the process? I have run Malwarebytes - it shows nothing unpleasant on
    the computer.
     
    Lorne, Jul 6, 2010
    #1
    1. Advertising

  2. Lorne

    poutnik Guest

    In article <>,
    says...
    >
    > I have Windows 7 home premium running on an AMD X6-1055 6 core processor.
    > If I start Windows and leave it doing nothing except the background
    > processes loaded at boot time the CPU runs continuously at 14/15%.
    >
    > When I inspect task manager it tells me system idle process is 99%, and none
    > of the 80 running processes register above 0%, but at the bottom CPU use is
    > still 14%+.
    >
    > When I look at the performance tab one processor (always the same one) is
    > running at 85-90% and the others near zero.
    >
    > When I use a motherboard utility it shows the same thing - one processor at
    > 85%+ and the others near zero.
    >
    > How do I find out what is running to cause this when task manager does not
    > show the process? I have run Malwarebytes - it shows nothing unpleasant on
    > the computer.


    Try to run Process Explorer by Sysinternals (now Microsoft),
    as elevated admin. I guess Win Task Manager need not to show all,
    PE may show more processes.

    http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx

    --
    Poutnik
    The best depends on how the best is defined.
     
    poutnik, Jul 6, 2010
    #2
    1. Advertising

  3. Lorne

    Lorne Guest

    "Lorne" <> wrote in message
    news:...
    > I have Windows 7 home premium running on an AMD X6-1055 6 core processor.
    > If I start Windows and leave it doing nothing except the background
    > processes loaded at boot time the CPU runs continuously at 14/15%.
    >
    > When I inspect task manager it tells me system idle process is 99%, and
    > none of the 80 running processes register above 0%, but at the bottom CPU
    > use is still 14%+.
    >
    > When I look at the performance tab one processor (always the same one) is
    > running at 85-90% and the others near zero.
    >
    > When I use a motherboard utility it shows the same thing - one processor
    > at 85%+ and the others near zero.
    >
    > How do I find out what is running to cause this when task manager does not
    > show the process? I have run Malwarebytes - it shows nothing unpleasant
    > on the computer.


    I made some progress. I found windows system monitor and it shows me that
    the cpu usage is caused by system interrupts. What I now need is to work
    out which interrupt is causing the problem. any idea how to do that?
     
    Lorne, Jul 6, 2010
    #3
  4. Lorne

    Lorne Guest

    "Lorne" <> wrote in message
    news:##...
    > "Lorne" <> wrote in message
    > news:...
    >> I have Windows 7 home premium running on an AMD X6-1055 6 core processor.
    >> If I start Windows and leave it doing nothing except the background
    >> processes loaded at boot time the CPU runs continuously at 14/15%.
    >>
    >> When I inspect task manager it tells me system idle process is 99%, and
    >> none of the 80 running processes register above 0%, but at the bottom CPU
    >> use is still 14%+.
    >>
    >> When I look at the performance tab one processor (always the same one) is
    >> running at 85-90% and the others near zero.
    >>
    >> When I use a motherboard utility it shows the same thing - one processor
    >> at 85%+ and the others near zero.
    >>
    >> How do I find out what is running to cause this when task manager does
    >> not show the process? I have run Malwarebytes - it shows nothing
    >> unpleasant on the computer.

    >
    > I made some progress. I found windows system monitor and it shows me that
    > the cpu usage is caused by system interrupts. What I now need is to work
    > out which interrupt is causing the problem. any idea how to do that?


    An interesting additional effect is that if I put the computer into sleep
    mode and wake it up the problem disappears - cpu down to 1 or 2% and use of
    cpu by interrupts under effectively zero.

    Does anybody have detailed knowledge of what sleep mode actually does that
    may change the behavior of interrupts?
     
    Lorne, Jul 6, 2010
    #4
  5. Lorne

    Nunya Guest

    On Jul 6, 9:18 am, "Lorne" <> wrote:
    > "Lorne" <> wrote in message
    >
    > news:##...
    >
    >
    >
    > > "Lorne" <> wrote in message
    > >news:...
    > >> I have Windows 7 home premium running on an AMD X6-1055 6 core processor.
    > >> If I start Windows and leave it doing nothing except the background
    > >> processes loaded at boot time the CPU runs continuously at 14/15%.

    >
    > >> When I inspect task manager it tells me system idle process is 99%, and
    > >> none of the 80 running processes register above 0%, but at the bottom CPU
    > >> use is still 14%+.

    >
    > >> When I look at the performance tab one processor (always the same one) is
    > >> running at 85-90% and the others near zero.

    >
    > >> When I use a motherboard utility it shows the same thing - one processor
    > >> at 85%+ and the others near zero.

    >
    > >> How do I find out what is running to cause this when task manager does
    > >> not show the process?  I have run Malwarebytes - it shows nothing
    > >> unpleasant on the computer.

    >
    > > I made some progress.  I found windows system monitor and it shows me that
    > > the cpu usage is caused by system interrupts.  What I now need is to work
    > > out which interrupt is causing the problem.  any idea how to do that?

    >
    > An interesting additional effect is that if I put the computer into sleep
    > mode and wake it up the problem disappears - cpu down to 1 or 2% and use of
    > cpu by interrupts under effectively zero.
    >
    > Does anybody have detailed knowledge of what sleep mode actually does  that
    > may change the behavior of interrupts?


    Sounds like motherboard level or OS level CPU slowdown protocols being
    implemented.
    IOW, 10% use at full speed is easy, whereas 10% use when the CPU is
    clocked down 80%
    is quite a lot of work for it.
     
    Nunya, Jul 6, 2010
    #5
  6. Lorne

    Lorne Guest

    SOLUTION - Re: CPU running continuously at 90% on one core

    If anybody else has this problem the procedure to find a solution is here:
    http://www.msfn.org/board/topic/140263-how-to-get-the-cause-of-high-cpu-usage-by-dpc-interrupt/

    It requires some reasonable understanding of computers to follow it however.
    In my case it was a driver called nmserial.sys that was hogging the cpu.

    **************************************************************************

    "Lorne" <> wrote in message
    news:...
    > I have Windows 7 home premium running on an AMD X6-1055 6 core processor.
    > If I start Windows and leave it doing nothing except the background
    > processes loaded at boot time the CPU runs continuously at 14/15%.
    >
    > When I inspect task manager it tells me system idle process is 99%, and
    > none of the 80 running processes register above 0%, but at the bottom CPU
    > use is still 14%+.
    >
    > When I look at the performance tab one processor (always the same one) is
    > running at 85-90% and the others near zero.
    >
    > When I use a motherboard utility it shows the same thing - one processor
    > at 85%+ and the others near zero.
    >
    > How do I find out what is running to cause this when task manager does not
    > show the process? I have run Malwarebytes - it shows nothing unpleasant
    > on the computer.
     
    Lorne, Jul 8, 2010
    #6
  7. Lorne

    Byte Guest

    Sleep will shut down power to USB ports if device is marked to conserve
    power. When you SLEEP you may be depowering some USB device that is
    interrupting the system trying to initialize after a full power up.

    Guessing here, but .......

    "Lorne" <> wrote in message
    news:Okb#...
    > "Lorne" <> wrote in message
    > news:##...
    >> "Lorne" <> wrote in message
    >> news:...
    >>> I have Windows 7 home premium running on an AMD X6-1055 6 core
    >>> processor. If I start Windows and leave it doing nothing except the
    >>> background processes loaded at boot time the CPU runs continuously at
    >>> 14/15%.
    >>>
    >>> When I inspect task manager it tells me system idle process is 99%, and
    >>> none of the 80 running processes register above 0%, but at the bottom
    >>> CPU use is still 14%+.
    >>>
    >>> When I look at the performance tab one processor (always the same one)
    >>> is running at 85-90% and the others near zero.
    >>>
    >>> When I use a motherboard utility it shows the same thing - one processor
    >>> at 85%+ and the others near zero.
    >>>
    >>> How do I find out what is running to cause this when task manager does
    >>> not show the process? I have run Malwarebytes - it shows nothing
    >>> unpleasant on the computer.

    >>
    >> I made some progress. I found windows system monitor and it shows me
    >> that the cpu usage is caused by system interrupts. What I now need is to
    >> work out which interrupt is causing the problem. any idea how to do
    >> that?

    >
    > An interesting additional effect is that if I put the computer into sleep
    > mode and wake it up the problem disappears - cpu down to 1 or 2% and use
    > of cpu by interrupts under effectively zero.
    >
    > Does anybody have detailed knowledge of what sleep mode actually does
    > that may change the behavior of interrupts?
    >
    >
     
    Byte, Jul 8, 2010
    #7
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. bigal
    Replies:
    0
    Views:
    1,193
    bigal
    Mar 22, 2006
  2. dimon
    Replies:
    4
    Views:
    870
    dimon
    Nov 10, 2006
  3. =?Utf-8?B?QVQ=?=
    Replies:
    5
    Views:
    2,745
    Tony Sperling
    Jun 12, 2007
  4. Spin
    Replies:
    9
    Views:
    1,655
    gregg
    Oct 1, 2009
  5. Becky

    Intel Core i7-3820 Quad-Core CPU

    Becky, Feb 23, 2012, in forum: Front Page News
    Replies:
    0
    Views:
    1,146
    Becky
    Feb 23, 2012
Loading...

Share This Page