[jtbayly]

It has been anti-confirmed by me. My iPhone 6S continues running at 50% CPU speed, even when charging from the OEM adapter. Only thing that makes it run (a little bit) faster is if the battery charge gets above 97%.

(Also worth noting that the battery in my phone still holds 87% original capacity.)

[starky]

That this is happening when the cell is still at 87% capacity is really the problem here. How do you justify degrading your system's performance when the cell is still soundly in the healthy region?

[cjensen]

Capacity is not power. Old batteries produce less power (volts times amps) no matter how full they are.

[walterbell]

What threshold(s) are used by Apple to determine when to throttle?

If a new battery is purchased today, how many months of daily usage will cause Apple throttling to begin?

If a Samsung and Apple phone are purchased on the same day, used the same amount and benchmarked each day for 24 months, would their performance graphs look similar?

[starky]

Regardless of what chemistry they are using, a lithium cell should be capable of producing more than enough power for a cellphone at any residual capacity before it becomes useless. You aren't discharging at more than 0.5C on a portable device.