In my Asus P4P800 BIOS, there's a Spread Spectrum setting in Chipset section with options of Enabled and Disabled. It's listed just below Graphic Adapter Priority and Graphics Aperture Size. Does the same rule of Disabled apply to this setting as the various Spread Spectrum (AGP Spectrum, CPU Spread Spectrum, FSB Spread Spectrum, etc) settings mentioned in BOG? Those in BOG have various % options, Disabled, but no Enabled option though.
The Enabled setting merely means you do not have any control over how much of a "jitter" is introduced to the frequency.
Spread spectrum continuously changes the frequency on which your components work with ±5%. This is to lessen the interference on an individual frequency. Though this will give you lower stability and higher power usage. You can try and disable it to see or there will be any problems (doubt it), if not just leave it disabled I guess.
Yes, but as I indicated in my original post, I wasn't sure if this setting is related to any of those listed in your BOG because of it's slightly different name and options. This setting is called exactly "Spread Spectrum" with nothing in front of it such as AGP, CPU, etc and doesn't have any percentage options as those in your BOG. When selected, it's referred to as "clock generator spread spectrum" in an info column.
Okay, can you tell me more about the available options? How about a screenshot? The idea behind spread spectrum is the same. It's just a matter of what it's being applied to.
Then it's impossible to know what it's being applied to. That depends on the motherboard manufacturer.
Asus manuals are as dumb as "Spread Spectrum - this enables or disables Spread Spectrum". Sorry to trouble you all with this, but I wanted to be sure. The same recommendation for similar settings in BOG probably applies to this.
In any case, the advice is the same, no matter whether it applies to the graphics card, CPU, etc... Spread spectrum is good for reducing EMI but for stability and overclockability, best to disable it.