Sempron 2200+ not recognized by A7V400-MX

Discussion in 'Asus' started by Jan Klaverstijn, Nov 16, 2004.

  1. Hi all,

    I just installed a new CPU in my Asus A7V400-MX. It was sold as an AMD
    Sempron 2200+. In order to get it recognized I flashed the latest BIOS
    version 1004 . However, it still tells me it sees a 900MHz cpu. I reset the
    default settings after flashing to no avail. Can I cure this or am I simply
    cheated when bying the cpu? I run Linux on that box. This is the content of
    /proc/cpuinfo:

    processor : 0
    vendor_id : AuthenticAMD
    cpu family : 6
    model : 8
    model name : AMD Athlon(tm)
    stepping : 1
    cpu MHz : 899.977
    cache size : 256 KB
    fdiv_bug : no
    hlt_bug : no
    f00f_bug : no
    coma_bug : no
    fpu : yes
    fpu_exception : yes
    cpuid level : 1
    wp : yes
    flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
    cmov pat pse36 mmx fxsr sse syscall mmxext 3dnowext 3dnow
    bogomips : 1795.68


    I need the additional performance badly. Please help.

    Kind regards,
    - Jan.
     
    Jan Klaverstijn, Nov 16, 2004
    #1
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  2. Jan Klaverstijn

    dino Guest

    have you gone in and set the FSB to 166 mhz in the BIOS?
     
    dino, Nov 16, 2004
    #2
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  3. Jan Klaverstijn

    Paul Guest

    According to this, it is supposed to read 1.8GHz.
    http://www.tomshardware.com/cpu/20040728/sempron-01.html

    With an FSB of 266, the clock should be 133. 1800MHz divided
    by 133MHz gives a multiplier of 13.5 .

    Have a look in the downloadable manual, as the paper manual in
    the motherboard box has at least one error when it comes to
    the DSW setting.

    http://www.asus.com.tw/pub/ASUS/mb/socka/km400a/a7v400-mx/e1817_a7v400-mx.pdf

    Make sure the DSW is set for 133MHz CPU clock, as that should
    cause the FSB to run at 266, and give you a core of 1.8GHz. Since
    not all the DSW settings are documented, maybe you've discovered
    a way to get a 66MHz clock fed to the processor ? Since nobody has
    read the numbers off the top of the clockgen chip on that board, I
    cannot look up what the other dip switch settings would do.

    HTH,
    Paul


    HTH,
    Paul
     
    Paul, Nov 16, 2004
    #3
  4. Jan Klaverstijn

    Driekes Guest

    Jan,

    Je moet de dipswitches op het moederbord instellen!

    Kijk even ik het manual voor de instellingen.

    Werner
     
    Driekes, Nov 16, 2004
    #4
  5. Thanks for your input; it will certainly set me on the right track.

    What I get from this is: I need to set the switch to a higher FSB. In
    fact the Sempron has a 333MHz fsb. This suggests I set the switch to
    166.67Mhz. This makes perfect sense as 166/100*900=1500, 900 being the
    current reading for processor speed and knowing that a 2200+ is in
    fact a 1500MHz. Bummer I missed the DSW; my "other motherboard" has no
    switches or jumpers so I just didn't look. I will do this tonight
    (currently I am in the office) but am confident this will make all the
    difference. One tinge of doubt comes from the remark in the doc that
    changing the switch settings does not make sense when the chip is
    locked. What's the story here?

    Thanks again,
    Jan.
     
    Jan klaverstijn, Nov 16, 2004
    #5
  6. Jan Klaverstijn

    Paul Guest

    Locking refers to the multiplier. The processor chip takes the
    external clock and multiplies it by a constant that is fixed
    during manufacturing.

    The DSW switches control the clockgen. They modify the external
    clock, and the processor has no influence over that clock signal.
    Thus, the clockgen is changable via the DSW.

    Overclocking can be done by either changing the external
    processor clock or by changing the multiplier. AMD has been
    shipping multiplier locked processors for some time, leaving
    the external clock generator as the only way to modify them.
    So, the DSW can be used for adjusting the processor to run at
    nominal conditions, or to overclock the processor. When using
    the external clock in this fashion, you may need faster memory,
    or the Northbridge itself may become the limiting factor in
    how fast the system runs. In addition, on some single channel
    motherboards, as you raise the memory clock, you cannot run a
    full set of DIMM modules, and have to reduce the number of
    DIMMs used. That means external clock modifying has its limits,
    and they may be related more to Northbridge or the memory bus
    than to the processor itself.

    HTH,
    Paul
     
    Paul, Nov 16, 2004
    #6
  7. Paul,

    As could be expected the processor is now recognized as 1500 MHz and the
    performance gain is very noticable.

    gatekeeper:/usr/local/httpd/bin# cat /proc/cpuinfo
    ....
    model name : AMD Sempron(tm) 2200+
    stepping : 1
    cpu MHz : 1494.004
    cache size : 256 KB
    ....

    Many thanks for the expert advice and background info, Paul. You could have
    done away with two lines of RTFM comments but instead choose to patiently
    elaborate. I appreciate this much, it's what makes these newsgroups work for
    me.

    Regards,
    Jan.
     
    Jan Klaverstijn, Nov 18, 2004
    #7
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