> how many watts are we really saving between lpddr5 and ddr5?
From what I gathered, it's around a watt per when idling (which is when it's most critical): the sources I found seem to indicate that ddr5 always runs at 1.1V (or more but probably not in laptops), while lpddr5 can be downvolted. That's an extra 10% idle power consumption per.
So rather than your battery lasting 15 hours it only lasts 14ish. Probably a rounding error considering how much a poorly coded website can impact your battery life estimates even on apple silicon, and the fact your battery degrades over its life anyhow and never gets what it says on the tin (especially apples tin).
From what I gathered, it's around a watt per when idling (which is when it's most critical): the sources I found seem to indicate that ddr5 always runs at 1.1V (or more but probably not in laptops), while lpddr5 can be downvolted. That's an extra 10% idle power consumption per.