Cannot Disable Spread Spectrum Settings in BIOS during OC

[guinness07]

I am embarking on my maiden voyage in overclocking and already running into some issues following what I thought were pretty simple directions from several overclocking guides (NVidia, other websites).

My current configuration is as follows:
Intel Core 2 Duo E6600 2.4GHz
Thermaltake heatsink
2 x 2GB G.Skill DDR2-1066 memory
Totac GTX 460 (768MB) - This is the reason I want to OC my CPU, my 8800gtx died and now trying to ease my CPU bottleneck even a tad.
eVGA 680i SLI motherboard
Truepower 550W PSU
Thermaltake Armor case

When I went into my Systems Clocks section in my Bios Advanced Chipset Features, I was unable to disable any of the Spread Spectrums outside of the CPU Spread Spectrum and the PCIe Spread Spectrums (SPP). I have no idea why I do not even have the option to disable the others, or whether it is critical for me to do so. I am a bit nervous that I'm going to fry my PC although I already downloaded CPU-Z, HWMonitor, Prime95, and other so I feel I have the tools in place to at least monitor.

Can anyone please provide me with some guidance on why I am encountering this issue?

Thanks!

 

[Zero82z]

What other spread spectrums? The only options I have ever seen were for CPU and PCI-E spread spectrum. You shouldn't need to worry about any others.