# FreeBSD and my videocard



## Kariddi (Oct 3, 2011)

Hi, I've been a FreeBSD user in the past and I would like to come back to the system now.

I have a Radeon 5850 video card and I would like to have a feedback about how the system runs with this video card. I don't require stellar performance or 3D rendering (of course, if present it would be well received), but what I'm most concerned with is downclocking of the card when idle. 

The card while in the BIOS or in Linux/Windows without a driver installed that manages the card clocks and voltage is very noisy. On Linux I use the FOSS drivers and set the profile to "low" and the card is very silent. Is it possible to do the same on FreeBSD?

Thanks

Marcello


----------



## wblock@ (Oct 4, 2011)

FreeBSD uses the same xorg driver as Linux.  Due to some kernel differences, [pman=4x]radeon[/pman] doesn't have acceleration for that card on FreeBSD yet.  Power management might work already.  Copy the settings from the Linux xorg.conf.


----------



## Kariddi (Oct 4, 2011)

wblock@ said:
			
		

> FreeBSD uses the same xorg driver as Linux.  Due to some kernel differences, [pman=4x]radeon[/pman] doesn't have acceleration for that card on FreeBSD yet.  Power management might work already.  Copy the settings from the Linux xorg.conf.



The problem is that the power management settings for my card are managed by the radeon KMS driver on linux. My xorg.conf file is not aware of power management on linux.

On linux I have this command that runs at boot (in /etc/rc.local) that sets the power profile to low:


```
echo low > /sys/class/drm/card0/device/power_profile
```

I imagine that something like this is not present on FreeBSD. Someone can confirm that power management for my card is supported on FreeBSD via the UMS driver?


----------



## adamk (Oct 4, 2011)

When using UMS, the radeon driver supports various options in xorg.conf for different power settings, specifically ClockGating, ForceLowerPowerMode, and DynamicPM.  They are not as configurable as the KMS options, from what I understand.  

Unfortunately, given the fact that KMS is required for acceleration on that GPU, it is quite possible, even likely, that the developers did not implement the UMS hooks for power management for your card.  Unfortunately, I do not have the hardware to test it.


----------



## kpedersen (Oct 4, 2011)

Out of interest, would using the vesa (instead of radeon) driver use up less juice?
Would not running X11 at all also save power or would the card still use the same amount?

Unfortunately I don't imagine these to be very good solutions for the OP but would be interesting to know.


----------



## wblock@ (Oct 4, 2011)

kpedersen said:
			
		

> Out of interest, would using the vesa (instead of radeon) driver use up less juice?



Untested, but I'd guess not.  The appropriate driver should be able to throttle power because it knows the hardware, even without specific power-saving enabled.



> Would not running X11 at all also save power or would the card still use the same amount?



A desktop with Radeon 4650 and either text console or xorg (xfce with composite enabled) draws 89 watts according to a Killawatt.  Start openarena, and it jumps to 115 watts.


----------

