It sounds unbelievable and is honestly almost amazing, but also completely true. The Athlon 64 3200+, which has begun to show up on the market, is has its multiplier locked from the factory. However, not all multipliers are physically locked and the reason for this is aptly named Cool’n’Quiet.
Some of you might recognize PowerNow! and for those who that don’t, we can tell that it is a technology which is mainly used on mobile AMD processors. It is used to increase battery time on your laptop by downclocking the processor when the computer isn’t connected to a power outlet and is working with less demanding applications. Cool’n’Quiet is a similar technology which also “underclocks” the processor when it is suitable and both these technologies use the processor’s multiplier to lower the clock frequency. In other words, this means that processors with Cool’n’Quiet support can’t have all multipliers physically locked since these techniques won’t work if they do.
Most of people has figured this out by now and Hiyohiyo is one of them. He’s the man behind the CrystalCPUID software.
CrystalCPUID is an application that not only works as a system/processor informator but can also manipulate the multiplier on certain AMD processors instantly from Windows. What is required is primarily a processor with support for PowerNow! or Cool’n’Quiet and subsequently a mainboard with BIOS support for the technology.
CrystalCPUID has support for both AMD K7 and K8 processors, but it is within the K8 and the Athlon 64 field where range of application is the widest. Even though Athlon XP processors with support for Cool’n’Quiet exist, these are more or less only OEM processors which are sold in Asia and we have no information about their availability in Europe. In addition, for the K7 architecture it is mobile processors that matters, which is not that attractive.
Nevertheless, it looks like all Athlon 64 processors have support for the Cool’n’Quiet technology; a fact which opens a wide range of new opportunities for overclockers in possession of Athlon 64 processors.
Since these technologies only underclocks the processors, it seems that the only multipliers available today are lower ones, but that’s nothing that bus-hungry overclockers could possibly complain about.
We have already seen several people that has succeeded with this and you may read more about their accomplishments here in Tbreak’s forum.
More about the support for Cool’n’Quiet is to be found here.