# [SOLVED]AMD phenom 955 cpufreq stops working when OC>3.7ghz

## mardicas

Hello,

could someone point me in the right direction why AMD Phenom || X4 955 BE cpu frequency control stops working when overclocked to 3.8Ghz but works just fine when OC to 3.7Ghz. It is stable, but just wont downclock when idle...

It says that it doesnt find any controllable CPU-s.

I have a GIGABYTE GA-785GMT-USB3 motherboard.

When 3.7Ghz

```
analyzing CPU 0:                                              

  driver: powernow-k8                                         

  CPUs which need to switch frequency at the same time: 0     

  hardware limits: 800 MHz - 3.70 GHz                         

  available frequency steps: 3.70 GHz, 2.50 GHz, 2.10 GHz, 800 MHz

  available cpufreq governors: conservative, ondemand, userspace, powersave, performance

  current policy: frequency should be within 800 MHz and 3.70 GHz.

                  The governor "ondemand" may decide which speed to use

                  within this range.

  current CPU frequency is 800 MHz.

  cpufreq stats: 3.70 GHz:75.55%, 2.50 GHz:0.41%, 2.10 GHz:0.40%, 800 MHz:23.64%  (127)

```

When 3.8Ghz

```
cpufrequtils 005: cpufreq-info (C) Dominik Brodowski 2004-2006

Report errors and bugs to cpufreq@vger.kernel.org, please.

analyzing CPU 0:

  no or unknown cpufreq driver is active on this CPU

analyzing CPU 1:

  no or unknown cpufreq driver is active on this CPU

analyzing CPU 2:

  no or unknown cpufreq driver is active on this CPU

analyzing CPU 3:

  no or unknown cpufreq driver is active on this CPU

```

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## roarinelk

Some BIOSes stop generating the necessary ACPI tables and/or

disable the necessary P-state transition support bit in an MSR

when you oc the cpu beyond some internal limits.

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## Ant P.

Yep, mine (an X3) seems to do that with even a small OC. No idea what the real reason is, but I'd guess it's to do with temperature/voltage changes between min/max speed becoming too large to do safely.

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## mardicas

Yep, core voltage or any voltage doesn't seem to be an issue. It's the Ghz that make the cange(i set everything manually only changing from 3.7 to 3.8 made it stop working)

Well...3.7 is enough for me  :Smile:  so i will stick with that.

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## mardicas

Found some interesting posts:

http://forums.guru3d.com/showthread.php?t=248938

http://hardforum.com/showthread.php?t=1042554

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