On Fri, Feb 25, 2011 at 6:03 PM, Phillip Susi <psusi at cfl.rr.com> wrote: > On 02/25/2011 03:38 PM, Alex Deucher wrote: >> >> The CP firmware has nothing to do with the temperature. ?The CP >> firmware is just a packet parser for reading in command buffers and >> programming the register backbone. ?Just alike a CPU, the GPU runs at >> whatever speed it's clock is set to. ?You can manually force lower >> power states using sysfs. ?See the power management section of this >> page: >> http://wiki.x.org/wiki/RadeonFeature > > I have tried writing low to power_profile and it seems to make little to no > difference. ?A cpu executing a tight loop busy waiting for something to do > wastes a lot more power than one that has executed a HLT instruction, or > used even better stop states to gate off clocks that are not needed. ?It > seems to me that when there is nothing for the GPU to do, it also should > stop executing instructions and gate off any unneeded clocks. >
It only executes instructions when you tell it to; it's not running constantly. At the moment clock gating support is not implemented on newer asics. Alex
