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CPU: Multiplier vs. Bus Speed? Answered

Hi. I have been overclocking my new cpu (AMD Phenom II X2 550 BE) and I was all excited about having an unlocked multiplier, because of the Black Edition, yet I can't even stably change it! I was told that you should up the CPU bus speed as much as you can while leaving the CPU stable, then move on to the multiplier. Yet after I get to the stable bus speed (235) I can't up the multiplier even one notch. It is currently 15.5. This was the stock multiplier. My question is, is it worth it to lower the bus speed so I can stably increase the multiplier. And is there a way to stably increase the multiplier even after you max out the bus speed that I am obviously not doing? Thanks in advance.



Best Answer 8 years ago

Your final clock speed is the product of the bus & multiplier. Increasing the bus speed will affect the memory also, leave that alone and try with the multiplier alone - check your temperatures though.


Yeah; really depends on your application - if you need more cpu cycles per memory cycle can make a difference, but in general you want the highest overall speed.  Like you also say it affects the memory - some memory can't handle a faster bus, so you lower the bus and up the multiplier.

Thanks. So I am going to try with the multiplier alone now. What is better for gaming; increasing both slightly or increasing the cpu more?

I cant say with any expert opinion - check forums at www.tomshardware.com or google overclocking.

I have already done some research and stuff on overclocking. Thanks though. I was just wondering if you knew what to increase first or what would be best.

Ok I'll try that. What would be better for gaming in your opinion? Thanks.

It doesn't matter. CPU speed = FSB x multiplier, I'm just suggesting you up the CPU speed with the multiplier not the FSB clock, because that may be causing instability in overclocking your memory too far.


The days of overclocking are mostly gone. Chips are made to tighter tolerances these days

Higher voltage may get you there, for this chip technology. But then you not only have the additional-heat problem; you also have the problem of other components which may not be happy with the increase.

Feel free to play (at your own risk, of course). But remember, even at best, the ability to overclock is emphatically NOT guaranteed; if the manufacturer thought it would run faster, they'd sell it as a faster chip. You may get lucky or you may not. Sounds like you didn't. You got what you paid for, so you've got no legitimate gripe.

Yeah I guess. But you are wrong. I did succeed. Just only to a certain extent (3.1GHz-3.6GHz)

When you change the cpu speed you may have to increase the voltage a bit.  I can get my computer quite a bit faster than stock but it have to kick up the voltage several steps.  Then this makes it run hotter so watch you cpu temp very carefully.

Yeah I have tried that too but nothing. Thanks.

That's not the depth of overclocking to be playing with unless you really know what your doing.