Re: AMD cpu slows down (I think)

From: Jonathan Berry (berryja_at_gmail.com)
Date: 10/30/04

  • Next message: W. Guy Thomas: "samba, FC3T3 to XP shares" 
    Date: Sat, 30 Oct 2004 12:25:35 -0500
To: For users of Fedora Core releases <fedora-list@redhat.com>

    Hi Trevor,

    On Sat, 30 Oct 2004 13:18:47 -0300, Trevor Smith <trevor@haligonian.com> wrote:
    > My situation: I have a Compaq Presario 2197CA, AMD Athlon XP-M 2800+ CPU. With
    > Fedora Core 1, no problems on AC or battery power. After upgrade to FC2 with
    > kernel-2.6.5-1.358, originally no problem (I don't recall). But at some point
    > I updated the kernel to kernel-2.6.8-1.521 and possibly then, possibly
    > because of some other "upgrade" my computer slips into a different mode when
    > on battery power.

    I have a Compaq R3000Z with an Athlon64 that is very similar to your
    R2197. You might look at the archives of the LinuxR3000 mailing list:
    http://quanta.homeip.net/mailman/listinfo/linuxr3000 While not
    directly applicable, there is some discussion about frequency scaling
    with the k8 driver. I'm using the k8 driver with powernowd, and
    frequency scaling works great.

    [snip]
    > After my long ramble, 4 questions:
    >
    > 1. am I correct in my assessment of the situation, do you think?

    Not sure, but probably on the right track. Look at the files in
    /sys/devices/system/cpu/cpu0/cpufreq/ Specifically cat the files
    scaling_available_frequencies and scaling_governor to see what
    frequencies you can run and what governor you are running. I know if
    I boot up on battery power, my laptop cuts off the highest frequency
    setting. Also, check that you are running cpufreqd or powernowd or
    something of the like. If you are using one of these, you
    scaling_governor should read "userspace" to use them.

    > 2. how could anybody want to use a system that is struggling to update windows
    > and such, no matter how much longer it made their batteries last?

    Certainly the performance you are describing is not good. With
    scaling, your processor should idle at a lower speed and then increase
    speed when it needs to do work. This prolongs battery life and saves
    power and heat as your processor can relax when it isn't doing
    anything useful.

    > 3. is my problem more likely the result of poor/nonexistent graphics
    > acceleration which causes the CPU to do graphics work as well as system work,
    > thus when the CPU is slowed down, graphics slow down?

    This could be true.

    > 4. how can I turn this d*** Powernow thing off?

    If you really want to turn it off, you can do this as root:
    echo "performance" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
    This will cause you cpu to always run at the highest available
    frequency. Now, this frequency could be lower if you are on battery,
    which is what I see on my laptop. The best thing is to use a
    governor. Powernowd is pretty good, and it's simple. You can get it
    from http://www.deater.net/john/powernowd.html Do some looking around
    in /sys/devices/system/cpu/cpu0/cpufreq/ and report back what you
    find.

    Jonathan 

    -- 
fedora-list mailing list
fedora-list@redhat.com
To unsubscribe: http://www.redhat.com/mailman/listinfo/fedora-list
  • Next message: W. Guy Thomas: "samba, FC3T3 to XP shares"

    Relevant Pages

    • Re: Why CPU speed is different
      ... Are you running off the battery when you are seeing this? ... this is why your laptop runs slower when on battery power vs when ... Unofficial FAQ for Windows Server 2003 at ... The bottom portion has CPU and Memory info. ...
      (microsoft.public.windowsxp.basics)
    • Re: Should I swich over to the Darkside? Pocket PC
      ... >>Well, given that Palm OS isn't by nature a multi-tasking OS, the ... >>chance of leaving an app running in the background is greatly reduced. ... was discussing battery consumption while the unit was powered off. ... *very* little battery power after it turns off the display. ...
      (comp.sys.palmtops.pilot)
    • Re: Control systems?
      ... >> basic transformer vs R/C, DCC, command control and whatever else may be ... This is specifically G scale. ... postings discussing battery power. ... Big advantage of battery power, is that you can use cheaper track (ie ...
      (rec.models.railroad)
    • Re: Desktop machine thinks its on batteries
      ... Anyway since I posted my question, the battery "X" icon has disappeared ... the battery sensing may be a component in some app you've found otherwise useful. ... You might check BIOS settings very carefully, altho it would be very unusual for a desktop mainboard BIOS to be looking at battery power. ...
      (microsoft.public.win2000.general)
    • Re: REQ: Any PCI-slot SW cards?
      ... This is not the same as operating a radio via PC. ... your notebook on the battery on a daily basis, ... Set up something like acarsd on your notebook and see how long it ... lasts on battery power. ...
      (rec.radio.shortwave)