# Does Freebsd 7 support intel speedstep technology?



## Michael (Jan 17, 2009)

I want to install FreeBSD 7 on my P4 630 machine (with i955x motherboard)ï¼ŒI wonder whether the CPU Frequency and Voltage can be automatically reduced when idle. Thanks in advance!


----------



## vermaden (Jan 17, 2009)

FreeBSD supports Intel's Speedstep a lot better then Linux.

You will need to add [cmd=]powerd_enable="YES"[/cmd] to /etc/rc.conf file and start the daemon with [cmd=]/etc/rc.d/powerd start[/cmd] command.


----------



## Android1 (Apr 6, 2009)

Good tip, vermaden. I was wondering about that myself.


----------



## hedwards (Apr 8, 2009)

vermaden said:
			
		

> FreeBSD supports Intel's Speedstep a lot better then Linux.
> 
> You will need to add [cmd=]powerd_enable="YES"[/cmd] to /etc/rc.conf file and start the daemon with [cmd=]/etc/rc.d/powerd start[/cmd] command.


And if one is going to do that, don't forget that you can tell powerd which type of algorithm to use. I believe there's thee, basically max performance, max battery life and a blend.

I'd look at /etc/defaults/rc.conf for more information. I bevieve that's where I found it, unfortunately I'm not in FreeBSD at the moment to check for sure.

The only fly in the ointment is that you need to make sure that acpi is working properly for this to actually work.


----------



## Android1 (Apr 8, 2009)

hedwards said:
			
		

> And if one is going to do that, don't forget that you can tell powerd which type of algorithm to use. I believe there's thee, basically max performance, max battery life and a blend.
> 
> I'd look at /etc/defaults/rc.conf for more information. I bevieve that's where I found it, unfortunately I'm not in FreeBSD at the moment to check for sure.
> 
> The only fly in the ointment is that you need to make sure that acpi is working properly for this to actually work.



If ACPI does not work after the installation, are there any tricks to get it working?


----------



## hedwards (Apr 12, 2009)

Android1 said:
			
		

> If ACPI does not work after the installation, are there any tricks to get it working?


Yes, I'd go to that portion of the handbook. The fixes go from having FreeBSD lie to the hardware about what OS it is to disassembling and debugging the DSDT.

What worked for me was adding the following to my /boot/loader.conf.
hw.acpi.osname="Windows 2001"

I personally like to add the following to my rc.conf for my desktop.

```
powerd_enable="YES"     # Run powerd to lower our power usage.
powerd_flags="-a adaptive"      # Flags to powerd (if enabled).
```


----------

