A more efficient CPU can't improve that spec because those workloads use almost no CPU time and the display dominates the energy consumption.

Unfortunately Apple only ever thinks about battery life in terms of web surfing and video playback, so we don't get official battery-life figures for anything else. Perhaps you can get more battery life out of your iPad Pro web surfing by using dark mode, since OLEDs should use less power than IPS displays with darker content.

Yeah double the PPW does not mean double the battery, because unless you're pegging the CPU/SOC it's likely only a small fraction of the power consumption of a light-use or idle device, especially for an SOC which originates in mobile devices.

Doing basic web navigation with some music in the background, my old M1 Pro has short bursts at ~5W (for the entire SoC) when navigating around, a pair of watts for mild webapps (e.g. checking various channels in discord), and typing into this here textbox it's sitting happy at under half a watt, with the P-cores essentially sitting idle and the E cores at under 50% utilisation.

With a 100Wh battery that would be a "potential" of 150 hours or so. Except nobody would ever sell it for that, because between the display and radios the laptop's actually pulling 10~11W.

On my M1 air, I find for casual use of about an hour or so a day, I can literally go close to a couple weeks without needing to recharge. Which to me is pretty awesome. Mostly use my personal desktop when not on my work laptop (docked m3 pro).

So this could be a bit helpful for heavier duty usage while on battery.

Ok, but is it twice as fast during those 10 hours, leading to 20 hours of effective websurfing? ;)

Isn't this weird, a new chip consumes 2 times less power, but the battery life is the same?

No, they have a "battery budget". It the CPU power draw goes down that means the budget goes up and you can spend it on other things, like a nicer display or some other feature.

When you say "up to 10 hours" most people will think "oh nice that's an entire day" and be fine with it. It's what they're used to.

Turning that into 12 hours might be possible but are the tradeoffs worth it? Will enough people buy the device because of the +2 hour battery life? Can you market that effectively? Or will putting in a nicer fancy display cause more people to buy it?

We'll never get significant battery life improvements because of this, sadly.

The OLED likely adds a fair bit of draw; they're generally somewhat more power-hungry than LCDs these days, assuming like-for-like brightness. Realistically, this will be the case until MicroLEDs are available for non-completely-silly money.

This surprises me. I thought the big power downside of LCD displays is that they use filtering to turn unwanted color channels into waste heat.

Knowing nothing else about the technology, I assumed that would make OLED displays more efficient.

OLED will use less for a screen of black and LCD will use less for a screen of white. Now, take whatever average of what content is on the screen and for you, it may be better or may be worse.

White background document editing, etc., will be worse, and this is rather common.

Can’t beat the thermodynamics of exciton recombination.

https://pubs.acs.org/doi/10.1021/acsami.9b10823

It's not weird when you consider that browsing the web or watching videos has the CPU idle or near enough, so 95% of the power draw is from the display and radios.