VPC 2004 SP1 travelling at relativistic speeds

Discussion in 'Virtual PC' started by Johan Johansson, Sep 14, 2005.

  1. Hi,

    I've been trying to figure out why my virtual XP SP2 machine appears so
    slow even though both host (also an XP SP2 machine) and guest have
    plenty of free CPU and memory. Window effects and menues appear very
    sluggishly, like on a machine that's swapping really heavily. I then by
    coincidence found out that time runs slower on that machine. That's
    right, I'm not saying that the machine runs slowly, I'm saying that time
    runs slower on it.

    By viewing the clock on both the guest and host I found the time
    dilation to be about a factor 7. It appears that if you ask for the
    current time you will get the right value, as the clock occasionally
    jumps a few minutes to the correct time. The problem seems to be timers.
    Another indication is that ping sends a packet very rarely, but the RTTs
    are "normal".

    As my intention is to run tests of our software in a virtual pc and our
    software implements protocols which are packed with timeouts, this is
    clearly a blocker for that.

    If this is a known problem with a known solution I've been googling for
    the wrong words. Either way, I'd greatly appriciate some pointers on how
    to solve this.

    Johan Johansson, Sep 14, 2005
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  2. Johan Johansson

    Robert Comer Guest

    You can try uninstalling then additions and reinstalling them.

    If you have the pre-SP1 additions installed in that VM, XPSP2 can be
    extremely slow...
    Robert Comer, Sep 15, 2005
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  3. Ok, now I've tried that, but time still runs more slowly in the VPC.
    Again, I'd like to stress that I am *not* having performance problems.
    My problem is that time seems to run about a factor 7 slower in the VPC
    than where I am, i.e. Sleep( 1000 ) will actually be Sleep( 7000 ) and
    timers (as in SetTimer) will expire much much too late.

    Johan Johansson, Sep 15, 2005
  4. Johan Johansson

    Robert Comer Guest

    Are you running this on a speedstep processor?

    I've never seen this much difference in the clock, maybe someone else has
    another idea.
    Robert Comer, Sep 15, 2005
  5. Indeed I am.

    Johan Johansson, Sep 15, 2005
  6. Johan Johansson

    Robert Comer Guest

    There are some issues with speedstep processors/chipsets, but usually there
    is a performance problem to go along with it. Maybe the same hotfix will
    help the situation though.

    You can get the hotfix by calling Microsoft Product Support and asking for
    Robert Comer, Sep 15, 2005
  7. Thanks! Just to make sure we're talking about the same thing, you mean
    the one with the symptom below?

    Microsoft Virtual PC 2004 and any virtual machines may stop responding
    after the computer resumes from hibernation. Virtual PC 2004 and the
    virtual machines may not respond for up to one hour.

    Johan Johansson, Sep 15, 2005
  8. Johan Johansson

    Robert Comer Guest

    Yep, that's the one. It seems to fix some other issues too...
    Robert Comer, Sep 16, 2005
  9. It's a big improvement but still on the order of 10 seconds too slow on
    a 5 minute period.

    Johan Johansson, Oct 3, 2005
  10. Johan Johansson

    Robert Comer Guest

    I don't think I've seen you mention the VPC additions, have you installed
    Robert Comer, Oct 3, 2005
  11. Johan Johansson, Oct 4, 2005
  12. Johan Johansson

    Robert Comer Guest

    Sorry about that, I didn't remember and I didn't have that message cached.

    I don't know anything else to try.
    Robert Comer, Oct 4, 2005
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