AMD/ATI PowerPlay-Support in radeon(ati) or radeonHD?

Vedran Rodic vrodic at
Sat Apr 5 05:49:35 PDT 2008

>  I've just added atombios support for the "DynamicClocks" option on
>  r5xx/r6xx cards to the radeon driver.  It should enable dynamic clock
>  gating and static power management if the chip supports it.  This is
>  not full powerplay support, just one aspect.  Also, the bios may set
>  some or all of this up at post so, YMMV.

Great, thanks.

My Sapphire 3850 Ultimate BIOS doesn't do anything to save power. The
machine when idle uses 81 watts under windows, 119 watts when in
BIOS/post/GRUB and 87 watts under Linux with fglrx.When I do a VT
switch to the text mode, power usage goas back to 119 watts, so the
fglrx driver is definitely doing something on rv670.  I still haven't
tested the power usage with "ati" driver though, but will later today.

For the X1950Pro the situation was opposite.  BIOS did setup power
saving, but fglrx switched it back to full power drain. I've concluded
this by measuring temperature in Windows. I know have a power usage
measuring device, so I'll report on that. For now, more details on
X1950Pro situation is at


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