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I don't think they are talking about the phone's total energy; the charts in that excellent paper you linked to have costs for CPU, L1, L2, DRAM etc but no scre

I don't think they are talking about the phone's total energy; the charts in that excellent paper you linked to have costs for CPU, L1, L2, DRAM etc but no screen, GPU, radio etc. A long time ago I was a technical product manager for, among other things, this stuff. At the time, the screen completely dominated and the GPU was a distant second, unless you were playing a 3D game, in which case it used almost as much as the backlight. CPU and radio were a long way behind them. My intuition is that this hasn't changed, as I can still get dramatically better battery life on my new iPhone in iBooks by playing with the brightness slider.

alecco 7y ago
Yes, the title of this thread is not clear.
lonelappde 7y ago
Per Carroll's results in An Analysis of Power Consumption in a Smartphone: The backlight is either the lowest power local component (10%, 40mW) or highest (50%, 400mW) depending on how bright it is turned up. The GSM radio is the highest power component (about 400mw), when it is working continuously (phone call). Related: a big contribution of smartphone OS optimizations and stuff like wifi 6 is about being smarter about turning off the radio for micro time slices when not needed. Laptops are similar, but it depends a lot on whether you are using a 15W CPU Ultrabook with no GPU, or 65W mobile workstation CPU plus a GPU.