Purpose of changing the multiplier?

hellrazor

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Feb 18, 2004
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I am overclocking an XP 2500 and was wondering what the purpose of changing the multiplier is and what the benifits are of lowering it or making it higher.

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Coyote

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Oct 1, 2003
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The formula for a cpu's operating "speed" is FSB x multiplier. Ex 200 x 11 = 2200 (3200+ speeds).

So, the multi is useful:

1) you want to acheive the highest FSB you can. So, lets say your cpu wont run above 2200mhz- you can reduce the multi to 10 and then run a FSB of 220. 220 x 10 = 2200

2) Your cpu is capable of speeds faster than you ram or mobo. Ex. say your ram or mobo can't go above 200, well then you can keep the FSB @ 200, but raise your multi to speed up your cpu without encountering instability due to ram or mobo chipset.

Basically, if the multi is locked, your only option for OCing is to raise the FSB. Just ONE variable to change.

If the multi is UNlocked, you now have two variables to play with in finding your optimal OC. It can simply make OCing a bit easier (and perhaps get you further).

Coyote

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Lazerous

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Where do changing the supplied voltages come into play with the formula?

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mozzartusm

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That can vary according to which CPU you are using. My P4 3.0E Overclocks better when small increases are added at around 210FSB. It takes quite a bit of voltage increase to get it to boot at 3.8 which is a big OC for this chip. My P4 3.4 Socket 775 CPU doesnt respond well to very much of a voltage increase. The range is much smaller, and the increases that are made must be in smaller increments. I would think that each model of CPU would have similiar characteristics, but at the same time they probably all have slightly different personalities!