a8n-sli-p and Spread Spectrum Clocking (SSC)

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

I've enabled SATA II 3G/ mode and that works fine. But what about this
option of Spread Spectrum Clocking (SSC)?

Question #1) Does the A8N-SLI-p support this? I could find nothing
about it in the manual or doing Google searches.

Question #2) If it does support this, would I want to enable SSC?
>From what I gather there may be a performance hit if I enable this. Is
that accurate?
4
answers
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More about spread spectrum clocking
  1. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    On 12 Aug 2005 12:27:49 -0700, edavid3001@gmail.com wrote:

    >I've enabled SATA II 3G/ mode and that works fine. But what about this
    >option of Spread Spectrum Clocking (SSC)?
    >
    >Question #1) Does the A8N-SLI-p support this? I could find nothing
    >about it in the manual or doing Google searches.
    >
    >Question #2) If it does support this, would I want to enable SSC?
    >>From what I gather there may be a performance hit if I enable this. Is
    >that accurate?

    <paste> (found this somewhere, years ago)
    When the motherboard's clock generator pulses, the extreme values
    (spikes) of the pulses creates EMI (Electromagnetic Interference). The
    Spread Spectrum function reduces the EMI generated by modulating the
    pulses so that the spikes of the pulses are reduced to flatter curves.
    It does so by varying the frequency so that it doesn't use any
    particular frequency for more than a moment. This reduces interference
    problems with other electronics in the area. However, while enabling
    Spread Spectrum decreases EMI, system stability and performance may be
    slightly compromised. This may be especially true with timing critical
    devices like clock-sensitive SCSI devices.
    </paste>

    So I guess if you had a radio or TV close to the PC and they were
    picking up noise you'd enable it. I never enable it and systems are all
    rock solid 24/7.

    Ed
  2. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    edavid3001@gmail.com wrote:
    > I've enabled SATA II 3G/ mode and that works fine. But what about this
    > option of Spread Spectrum Clocking (SSC)?
    >
    > Question #1) Does the A8N-SLI-p support this? I could find nothing
    > about it in the manual or doing Google searches.
    >
    > Question #2) If it does support this, would I want to enable SSC?
    >>From what I gather there may be a performance hit if I enable this. Is
    > that accurate?

    I have not seen such an option in the BIOS. Generally the only purpose
    of spread-spectrum clocking is to reduce RF interference levels, so it
    is mainly important to system manufacturers trying to get FCC certification.

    --
    Robert Hancock Saskatoon, SK, Canada
    To email, remove "nospam" from hancockr@nospamshaw.ca
    Home Page: http://www.roberthancock.com/
  3. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    Bitstring <qgjsf19143rhfop8t9egdgtv2aijq8em26@4ax.com>, from the
    wonderful person Ed <spam@hotmail.com> said
    >On 12 Aug 2005 12:27:49 -0700, edavid3001@gmail.com wrote:
    >
    >>I've enabled SATA II 3G/ mode and that works fine. But what about this
    >>option of Spread Spectrum Clocking (SSC)?
    >>
    >>Question #1) Does the A8N-SLI-p support this? I could find nothing
    >>about it in the manual or doing Google searches.
    >>
    >>Question #2) If it does support this, would I want to enable SSC?
    >>>From what I gather there may be a performance hit if I enable this. Is
    >>that accurate?
    >
    ><paste> (found this somewhere, years ago)
    >When the motherboard's clock generator pulses, the extreme values
    >(spikes) of the pulses creates EMI (Electromagnetic Interference). The
    >Spread Spectrum function reduces the EMI generated by modulating the
    >pulses so that the spikes of the pulses are reduced to flatter curves.
    >It does so by varying the frequency so that it doesn't use any
    >particular frequency for more than a moment. This reduces interference
    >problems with other electronics in the area. However, while enabling
    >Spread Spectrum decreases EMI, system stability and performance may be
    >slightly compromised. This may be especially true with timing critical
    >devices like clock-sensitive SCSI devices.
    ></paste>
    >
    >So I guess if you had a radio or TV close to the PC and they were
    >picking up noise you'd enable it. I never enable it and systems are all
    >rock solid 24/7.

    *cynical answer*
    Basically it helps them pass the EMI tests of the FCC et. al. Once
    they've passed the tests, they really don't expect anyone to ever turn
    it on.

    --
    GSV Three Minds in a Can
    Contact recommends the use of Firefox; SC recommends it at gunpoint.
  4. Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

    Okay, thanks. Hitachi ships SATA II harddrives in SATA I mode. I've
    gone into the harddrive settings (not motherboard settings) to enable
    SATA II and I had to select between enabling or disabling Spread
    Spectrum Clocking before I could save the SATA settings.

    Having never heard of it, I wasn't sure what I should select. There
    was not a default.

    Now I know. Thank you.

    Edwin
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