Created attachment 36247 [details]
my x1900xt's bios
Kernel 2.6.35-rc3, Xorg-Server 1.8.1, xf86-video-ati 6.13.0
For some weird reason my system consumes ~15W more when I set the power_profile to auto, compared to all other power-profiles (low, default and high all consume the same amount of power). I measured this with a powermeter.
"cat /debug/dri/0/radeon_pm_info" always says:
default engine clock: 500000 kHz
current engine clock: 499500 kHz
default memory clock: 600000 kHz
current memory clock: 594000 kHz
PCIE lanes: 0
No matter which power_profile I select.
My card is a ATi X1900XT. dileX_ on #radeon suggested that I attach my video-card bios, so I'll do that.
Most pre-r6xx desktop cards, including yours, do not offer power saving states in the power tables. As such all power states are the same on your card. auto does nothing on your card as well since all it does is wait for for acpi power plug events and switch between lower and higher power states when that happens. Since your system is a desktop, there is no acpi power plug event.