Mailinglist Archive: radeonhd (333 mails)

["Yang Zhao" <yang@xxxxxxxxxx>]

2008/10/8 Rafał Miłecki <zajec5@xxxxxxxxx>:
> Did you compare power consumption with and without patch?

I gathered some numbers through ACPI battery state, but I frankly
don't trust it.

On my T60, no wireless, lowest brightness, and CPU at lowest stepping
mode yielded ~15W with stock radeonhd. Switching on PowerPlay dropped
this number slightly, but I personally don't consider it statistically
significant. Manually switching to mode 0, which down-clocks GPU and
memory as low as it will go, gives 0.5 to 0.8W of saving.

It seems that the hardware already initializes to a fairly efficient
state, at least for me, regardless of PowerPlay.

As I understand it, dynamic clock gating of the memory controller
block and dynamic voltage drop can yield more, but these areas are
proving problematic.


> How hard will it be to introduce R600/R700 support in your patch?

I've been told PowerPlay was changed entirely for R600, so it's hard
to say until they give us those headers. In any case, the AtomBIOS
portion will most likely just work, or do nothing; the existing
bit-banging parts won't affect and can't be re-sued for R600+
PowerPlay at all.

Yang