Multiplier Question

[Yangsing]

I'm a newb when it comes to OCing and I've read up on some of the sticky threads in the AMD CPU forum. One question I had was, why would you want to unlock the multiplier in the first place? Could you not just raise the FSB by itself using 1/4-1/5 dividers or use one of the new nforce2 boards that are coming soon?

I'm just curious is why people are unlocking AMDs for the purpose of lowering the multiplier? Whats the real benefit over just raising the FSB by istelf and leaving the multiplier at the default value?

Thanks for anyone who can help in advance

Laters,
Yangsing "Achoo"

 

[Pinky]

Higher bus speeds = higher bandwidth = faster PC performance

 

[a1cnolan]

okay... im a newb too but i was surfin aroun and saw an article. it was like a whole hour ago so don't expect me to be able to tell you where i saw this but here goes what i took from it...its like the clock ratio(multiplier) controls the switching of the transistors inside the processor(or something).upping the mulitplier can make the transistors move too fast causing electrons to go places they shouldn't and other such madness.upping the fsb can also do the same thing.so basically when you hit your processors limit you gotta stop or it just won't workout for you. so what you do is find the limit and then take your multiplier down to see what kind of fsb you can get before you hit that limit and still be stable. it gives you more options. like i just unlocked mine tonight. just couldn't get my 1600 stable at 166... im sure its a ram issue but if i can push the ram a little more at the cost of a few mhz hit ill take it cause i game. while if you do other processor heavy apps you may want to go for the mhz. i dunno.. its up to you. or you can find your best processor limit and your best fsb limit and runi whichever one you need at that moment for what you are doing..... someone help me did i explain that right at all?

 

[Deathknight]

Well the purpose is somewhat 2fold. First off the equation for cpu speed is MULT X FSB = CPU SPEED. Increasing FSB will give you better performance compared to simply raising the multiplier. This is because of the extra memory bandwidth. Your processor is gunna top out somewhere regardless of how you raise it. If you lower the multiplier you can raise the fsb more though. While your actual cpu speed may be the same the extra fsb will increase your memory bandwidth, thus making your machine run better in memory intensive applications.

As mentioned before the other benefit is the flexibility in investigating what is holding you back. You can find if its your cpu or your memory that is the culprit holding you back by lowering your mult much lower and increasing fsb. If comp is still unstable its more than likely not the cpu that hit its ceiling.