# radeonfb equivalent? (power saving in console for ATI/AMD cards)



## ReverendRed (Dec 14, 2009)

Hi everyone!

I wonder if there is a way to dynamically reduce the clock speed of ATI/AMD gfx cards when the system is running in text/console mode. Under Linux, there is a kernel module called "radeonfb" which does the job, but I could not find an equivalent for FreeBSD.

Under X, everything is alright with radeon "dynamic clocks"- but I want my system to start up in console mode and my ATI HD4670 sucks 20W+ if it's not throttled, which is simply intolerable for a "low power" system.

Average IDLE power consumption : 
Win7 - 52W
Linux - 66W 
FreeBSD - 74W

.. not too much, but FreeBSD is waaaay behind and I want to keep it as low as possible as our bloody local energy supplier raised the prices again- System is Intel E8500/3.16Ghz, Sapphire HD 4670, 4 GB RAM, 2x SATA HD, 1x IDE DVD/RW)


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## DutchDaemon (Dec 14, 2009)

Are you at least running powerd(8)? On my 2*2200 MHz laptop I usually drop back to 100-300Mhz in a matter of seconds when doing nothing interactive (like reading). Saves a lot of power, heat and fan noise


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## oliverh (Dec 14, 2009)

DutchDaemon said:
			
		

> Are you at least running powerd(8)? On my 2*2200 MHz laptop I usually drop back to 100-300Mhz in a matter of seconds when doing nothing interactive (like reading). Saves a lot of power, heat and fan noise



Did you measure it? I saw some power savings in my laptop (Intel C2D P8600) but only in the official range between 800 and 2400MHz. Below that I see just sluggish behaviour.

See also the tuning example in FreeBSD wiki:

http://wiki.freebsd.org/TuningPowerConsumption


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## DutchDaemon (Dec 14, 2009)

I didn't measure it (the heat and the noise have subsided greatly though ). I'm using hiadaptive for my laptop (even on AC), and there's absolutely no sluggishness. The CPU steps[1] up and down from 2200 (it's even 2201 under FreeBSD 8 now ..) to 100 in a few seconds, with no visible or noticeable performance penalties whatsoever.

[1] 2201 1925 1600 1400 1200 1050 900 800 700 600 500 400 300 200 100


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## ReverendRed (Dec 14, 2009)

Thanks guys for some useful hint that kicked out some watts... Anyway, the gfx card's still the main cause of my energy problems, as (fairly) recent ATI models do not seem to be capable of hardware-based power management. 

However, at least they provide some sort of acceleration with open source drivers, while recent NVIDIA cards (often) refuse to work with open source drivers AT ALL (e.g. the 200-series on my PC) and their official driver still crashes. :-(

Choosing ATI or NVidia is still like choosing between the devil and the deep blue sea. Oh, well, Beastie would choose the devil. :e


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## DutchDaemon (Dec 14, 2009)

What is the power consumption with powerd enabled and in idle state?


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## oliverh (Dec 14, 2009)

ReverendRed said:
			
		

> Thanks guys for some useful hint that kicked out some watts... Anyway, the gfx card's still the main cause of my energy problems, as (fairly) recent ATI models do not seem to be capable of hardware-based power management.
> 
> However, at least they provide some sort of acceleration with open source drivers, while recent NVIDIA cards (often) refuse to work with open source drivers AT ALL (e.g. the 200-series on my PC) and their official driver still crashes. :-(
> 
> Choosing ATI or NVidia is still like choosing between the devil and the deep blue sea. Oh, well, Beastie would choose the devil. :e





```
Option "ForceLowPowerMode" "true"
Option "DynamicPM" "true"
```

Those options in section device should do the trick with radeonhd 1.3.0


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## ReverendRed (Dec 14, 2009)

DutchDaemon said:
			
		

> What is the power consumption with powerd enabled and in idle state?



About 70 watts now... still not good enough.


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## ReverendRed (Dec 14, 2009)

Update: Switched from radeon to radeonhd under X11 and got down to about 63 watts. - Thanks for that hint. (Scrolling and window movement is a bit more sloppy in radeonhd than in radeon, though...)

- However, this still does not solve my problem of power consumption in text mode.


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## oliverh (Dec 14, 2009)

Did you enable DRI and EXA as acceleration in section device?

Option     "AccelMethod"   "EXA"
Option     "DRI"          "True"


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