1 Reply Latest reply on Jul 10, 2013 11:54 PM by himanshu.gautam

    About setting different CPU frequency?

    stream101

      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