well, my best guess cause i haven't read anything definitive:
theoretically, it's all to improve stability of system when overclocking..whether it does or not is questionable.
pci-e to stabilize vid card when overclocking..not necessary from my experience anyway. more important to keep the frequency at a reasonable level.
mch- can't remember..southbridge or northbridge..likely northbridge voltage..careful with this one..the northbridge if that's the one already runs really hot. .1 volts may not seem like much but.
fsb- totally unsure of this one.. i suspect it's the northbridge voltage..again, be very careful on this one. not recommended to touch the mch and fsb voltages if you can avoid and get results you want.
i wouldn't go any higher than .1 on fsb and mch and not touch pci-e freq or voltage at all. doesn't take much to heat up the vid card gpu.
theoretically, it's all to improve stability of system when overclocking..whether it does or not is questionable.
pci-e to stabilize vid card when overclocking..not necessary from my experience anyway. more important to keep the frequency at a reasonable level.
mch- can't remember..southbridge or northbridge..likely northbridge voltage..careful with this one..the northbridge if that's the one already runs really hot. .1 volts may not seem like much but.
fsb- totally unsure of this one.. i suspect it's the northbridge voltage..again, be very careful on this one. not recommended to touch the mch and fsb voltages if you can avoid and get results you want.
i wouldn't go any higher than .1 on fsb and mch and not touch pci-e freq or voltage at all. doesn't take much to heat up the vid card gpu.