Bios Question ??

deonh911 · Nov 5, 2004

HI

Just a like to find out ,in my bios for cpu setup i have a field that says
cpu fsb clock is that where i set my bus frequency it is set to 133 mhz spec sheet on this site for axda 2400dkv3c bus frequency is 266mhz.

Secondly there is a field to enable or disable spread spectrum what does that
mean (Or what does it do ).

Regardz

Didou · Nov 5, 2004

Your FSB does actually run at 133mhz but due to its DDR (Dual Data Rate) nature it uses the rising & lowering edge of each clock thus working as efficiently as a true 266mhz FSB.

FSB Spread Spectrum

This BIOS feature allows you to reduce the EMI of the front side bus (known alternately as the FSB or processor bus) by modulating the signals it generates so that the spikes are reduced to flatter curves. It achieves this by varying the frequency slightly so that the signal does not use any particular frequency for more than a moment.

The BIOS usually offers two levels of modulation - 0.5% or 1.0%. The greater the modulation, the greater the reduction of EMI. Therefore, if you need to significantly reduce the front side bus' EMI, a modulation of 1.0% is recommended.

In most conditions, frequency modulation via this feature should not cause any problems. However, system stability may be compromised if you are overclocking the front side bus. Of course, this depends on the amount of modulation, the extent of overclocking and other factors like temperature, etc. As such, the problem may not readily manifest itself immediately.

Therefore, it is recommended that you disable this feature if you are overclocking the front side bus. The risk of crashing your system is not worth the reduction in EMI. Of course, if EMI reduction is important to you, enable this feature by all means. But you should reduce the clock speed a little to provide a margin of safety.

If you are not overclocking, the decision to enable or disable this feature is really up to you. But unless you have EMI problems or sensitive data that must be safeguarded from electronic eavesdropping, it is best to disable this feature to remove the possibility of stability issues.

Taken from -> FSB Spread Spectrum

deonh911 · Nov 6, 2004

Thanks Diduo

You helpd me a lot on anderstanding this unending frontier of space (mostly in my brain.) :grinthumb

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Bios Question ??

deonh911 Newcomer, in training

Didou Bowtie extraordinair!

deonh911 Newcomer, in training