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About setting different CPU frequency?

Question asked by stream101 on Jul 10, 2013
Latest reply on Jul 10, 2013 by himanshu.gautam

Hi,

 

My machine is AMD Phenom(tm) II X6 1100T Processor. I need to set different CPU frequency for different cores in my work. I read the "BIOS and Kernel Developer's Guide" manual and found I can achieve this by setting P-states correspondingly. So here is what I did, all the operations are performed for CPU0:

 

First I wrote 3 to MSRC001_0062, indicating the P-state is 3.

Then I set MSRC001_0067, which specify the register frequency and voltage of P-state 3. I particularly set bit 8:6(CpuDid) to 1 while keeping other fields unchanged. According to the formular:

CPU COF = 100 MHz * (CpuFid + 10h) / (2^CpuDid)   

Now I should be able to lower CPU's frequency to a half of the old value, but when I checked /proc/cpuinfo, the frequency was still the original value.


Did I perform sth wrong ? Can anyone give me some ideas? I am really lost now....


A lot of  thanks !!!!!!


-Xin

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