NF7-S v2.0 : Why does FSB above 200MHz fluctuate?

Discussion in 'Abit' started by Wayne Youngman, Dec 15, 2003.

  1. Hi,

    had a bit more spare time to play with my 3 month old AMD rig. I have
    become aware that my FSB is changing by itself, even though it is set at
    220MHz FSB in BIOS?.

    The machine is running stably, but I am curious. One program that shows
    this issue is CPU-Z (CPU Tab) where it shows you your FSB. Mine changes up
    and down from 210MHz-FSB to 220MHz-FSB. My motherboard only does this when
    I select above 200MHz-FSB. Could it be a sign that my PSU is beginning to
    show the strain (ANTEC 300w) or just that the NF7-S is a little *wobbly* at
    holding high value FSB.

    I have captured a small video clip (.mov 3.4MB) that shows what I'm talking
    about. Maybe you broadband owing dudes could take a quick peek at it for
    me. .

    http://www.waynes.spamtrap.btinternet.co.uk/CPUz_NF7s_Wobbly_FSB.MOV

    Any ideas?
    --
    Wayne ][

    Barton (AQXEA) XP2500+ @ 2.2GHz (10x220) - 1.775vCore
    CoolerMaster Aero 7 Lite - 3,200rpm
    ABIT NF7-S (v2.0 - BIOS#14)
    512MB Dual TwiSTER PC3500 @ DDR440 1:1 (9,3,3,2.0 - 2.7v)
    Sapphire Atlantis 9800 - 3.3ns Samsung (325/290 Default)
    240GB (2x120GB) WD-SE SATA RAID-0 (NTFS - 16k Stripe)
    Antec SX630II Mini-Tower Case Inc 300w PSU
    2 x CoolerMaster 80mm Blue Neon Fans
    WinXP-PRO-SP1
    Cat 3.7 - DX9.0b
     
    Wayne Youngman, Dec 15, 2003
    #1
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  2. Wayne Youngman

    IC Guest

    AFAIK, the FSB frequency is set by a PLL (Phased Lock Loop) integrated
    circuit chip. Perhaps a capacitor or other component is missing from
    the MB near that circuitry. An insufficient power supply would not
    cause the FSB or the CPU frequency to vary like that. I've never seen
    anything like that with any system I've built, including the current one
    with a NF7-S and the FSB is running at 220 MHz (XP1700+ running at 2200
    MHz).
     
    IC, Dec 16, 2003
    #2
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  3. Wayne Youngman

    Leadfoot Guest

    I think you would be on the right track in replacing the PSU. 300w is very
    low end now a days

    Usually it will change just a wee bit but yours is way out of whack

    Weird video
     
    Leadfoot, Dec 16, 2003
    #3





  4. Hi guys,
    thanks for feedback. Yes it is a funny video, made on a new NIKON coolpix,
    the light was very low and I was handholding the camera so that's why its so
    wobbly. So you think the most likely culprit is the PSU. I agree a 300w
    ANTEC is cutting it close with my fairly loaded system. Weird thing is it
    doesn't cause any instability problems, but I hate to see hardware that is
    doing *Mysterious* things!.

    Guesses so far:

    1) PSU is too weak to juice all the components
    2) The Mobo may have some slight defect

    Oh well if I find anything else out I will post back. .
    --
    Wayne ][

    Barton (AQXEA) XP2500+ @ 2.2GHz (10x220) - 1.775vCore
    CoolerMaster Aero 7 Lite - 3,200rpm
    ABIT NF7-S (v2.0 - BIOS#14)
    512MB Dual TwiSTER PC3500 @ DDR440 1:1 (9,3,3,2.0 - 2.7v)
    Sapphire Atlantis 9800 - 3.3ns Samsung (325/290 Default)
    240GB (2x120GB) WD-SE SATA RAID-0 (NTFS - 16k Stripe)
    Antec SX630II Mini-Tower Case Inc 300w PSU
    2 x CoolerMaster 80mm Blue Neon Fans
    WinXP-PRO-SP1
    Cat 3.7 - DX9.0b
     
    Wayne Youngman, Dec 16, 2003
    #4
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