# powerd (9.0-RELEASE)



## kpedersen (Feb 26, 2012)

Hi All,

I am having some issues with CPU scaling since updating to FreeBSD 9.0

I have in /etc/rc.conf

```
powerd_enable="YES"
```

But when I do 
	
	



```
# powerd -v
```
 I get an output as follows:-


```
blue# powerd -v
powerd: using APM for AC line status
powerd: error reading current CPU frequency: Device not configured
powerd: error reading current CPU frequency: Device not configured
CPU frequency is below user-defined minimum; changing frequency to 900 MHz
powerd: error setting CPU freq 900: Device not configured
powerd: error reading current CPU frequency: Device not configured
powerd: error reading current CPU frequency: Device not configured
powerd: error reading current CPU frequency: Device not configured
```

Do I need to *kldload* anything?
(The processor is a P4)

Also, do I still need to do the C-state stuff?

```
# sysctl dev.cpu.0.cx_lowest=C2
# sysctl dev.cpu.1.cx_lowest=C3
```

Any help would be appreciated.


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## Sylgeist (Mar 5, 2012)

I know on my server I fought for a few days trying to figure out why it was running strangely. I ended up commenting out the following in my sysctl.conf file:


```
dev.cpu.0.cx_lowest=C3
dev.cpu.1.cx_lowest=C3
```

I don't think I ever saw an explanation about it. I meant to follow up.


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## ahavatar (Mar 6, 2012)

Does P4 support CPU scaling?


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## phoenix (Mar 6, 2012)

Yes.  Depending on the CPU, via acpi_throttle, p4tcc, and/or est.


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