https://bugzilla.kernel.org/show_bug.cgi?id=91861
--- Comment #14 from Christian König deathsimple@vodafone.de --- (In reply to Mike S. from comment #13)
So, from your explanation, using a ref_div of 7 compared to 2, means that the VCO is running at a higher frequency, and hence, higher voltage. So I assume that would mean the GPU would be drawing more power & therefore run hotter, though I am not sure how significant this is to its overall power use.
Is that right?
No, just the other way around. A higher reference divider results in a lower post divider and a lower feedback divider and that in turn results in a lower voltage and lower power consumption.
But the over all power consumption of a PLL compared to the whole system or even the GFX block is completely neglitable. I would guess something between a 1/1000000 and 1/100000 of a Watt compared to a couple of Watt for the whole system.