Re:iPhone Performance Degrades as Battery Ages
by bjackman on Tuesday December 19, 2017 @06:14PM
(#15965357)
I worked on Android power perf (frequency scaling in particular) for the last 18 months and I'm not aware of any linkage with the battery state, except for the Battery Saver mode. So yeah same perf, just shorter life. There could be something in vendor Android builds I don't know about, but it isn't there in AOSP and almost certainly isn't in Pixel/Nexus.
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Re:iPhone Performance Degrades as Battery Ages
by londons_explore on Tuesday December 19, 2017 @08:25PM
(#15966175)
I vaguely remember the dram and camera clock rates being reduced when the battery SoC went under 40% in the nexus 5, and then when users complained of early shutdowns when using the camera with HDR mode, an update changed it to 60%.
I think I even commented on the bugreport that it would be best to do the frequency scaling based on interrupts from the voltage regulators on board, but that piping all the necessary drivers/events to do that with low enough latency to not cause an under-voltage reset was far more work than was feasible.
Thats also why 60fps video dropped frames at the start of the video if you were recording video with less than 60% battery.
Anyone care to dig out the relevant commit...?