"Spread spectrum" helps to overclock?

[Freshbrain]

The "spread spectrum" feature is present in almost all newer boards, I've read that it reduces Electromagnetic interference (EMI) around the whole board by slightly modifying the FSB freq. and so it adds some stability. Anyone tried that? Besides, what is "Autodetect PCI/Dram freq", I've seen that feature in all newer boards too. Thnx

 

[gdawson6]

Always wondered what that was....dont understand how getting rid of interference helps to overclock though...Solteks also have all kind of 'Skew' options which i was afraid to mess around with.

 

[rimshaker]

No, just the opposite actually. Disabling the spread spectrum feature will HELP in overclocking.

 

[arga]

Yes, its true, Toms Hardware said it is good to DISABLE IT.

And about the "Autodetect PCI/Dram freq" I am not entirely sure.


Arthur

 

[dkozloski]

Spread Spectrum dithers the CPU frequency which, in itself, is instability.

 

[Wind]

Disabled the Spread Spectrum will help O/Cing.

The autodectect PCI/DRAM Freq is let the mobo to run the default of 33 Mhz for PCI & 100/133 MHZ for FSB. The mobo will kick in the relevant PCI divisor.

 

[Freshbrain]

Well, the spread spectrum seems to be bad for oc then, I've tried it but found no difference really. The autodetect PCI/Dram would ignore my manually set FSB then? Or would it just change dividers for PCI, AGP, Dram, etc. Thanks a lot

 

[arga]

haha good question. I still don´t understand...

Arthur

 

[dkozloski]

Dithering the CPU clock frequency distributes the power of the EMI across a band rather than concentrating it in one frequency. This reduces the peak power of the noise but the average power remains the same. This is a gimmick to get around FCC regulations on EMI radiation. Theoretically this could reduce the stability of the computer but if you are operating that close to the edge you'll have worse problems that this.

 

[Jerboy]

<< The "spread spectrum" feature is present in almost all newer boards, I've read that it reduces Electromagnetic interference (EMI) around the whole board by slightly modifying the FSB freq. and so it adds some stability. Anyone tried that? Besides, what is "Autodetect PCI/Dram freq", I've seen that feature in all newer boards too. Thnx[/q


My Abit BE6 has an option for enabling/disabling spread spectrum. My Gigabyte GA-7DXR don't. Is it on by default or off by default on newer boards that doesn't have a choice?