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Comment by charlie0 | Hacker News Reader

Just an observation, I have an M1 Max and M3 Pro. The M3 Pros battery seems to drain much much faster than my M1 when watching YT. Wonder if this P core thing has anything to do with it.

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M3 has AV1 hardware decoding built in, it should increase battery life in theory. Check the codec used by YT using stats for nerds.

But no encoding :(

This extension lets you enable/disable codecs on YouTube[1]. It's also available for Chromium-based browsers, as well.

From what I've seen, though, is that M3 machines tend to consume more power than the M1 generation.

[1] https://addons.mozilla.org/en-US/firefox/addon/h264ify/

I believe Youtube just uses VP9 if you don't have AV1 hardware decoding. At least that's what consistently happens on my Mac using various browsers.

Could AV1 be more costly to decode, even in hardware, compared to VP9?

There is no web standard to list what codecs are hardware accelerated—good for fingerprinting resistance, bad for battery.

Browsers can just limit the codecs they claim to support to those that the system supports in hardware.

I believe that's what Safari did for a while with VP8 or VP9 – it was only available while plugged in on my old Mac if I remember correctly. There was a developer option called "support VP9 even on battery power" or something similar.

You can force AV1 through YT settings. https://www.youtube.com/account_playback

Is AV1 more energy efficient than h264?

Sure, AV1 is the better, newer codec, but h264 has been around for a long time and is certainly implemented very efficiently in the HW decoder.

From the independent battery tests I've seen the battery life should be noticeably better. Did you take a look at Activity Monitor to see if something is using high CPU?

Can you link to any one of the tests you've seen? I'm seeing similar results though for different reasons; and it's too early for me to call.

>...From the independent battery tests I've seen...

This test for example shows the longest battery life they have ever measured: https://www.pcmag.com/reviews/apple-macbook-pro-14-inch-2023...

> In our video rundown test, the 14-inch Pro lasted even longer, crossing the 30-hour threshold, becoming the longest-lasting laptop we've ever tested.

In this video they compare the M2 Pro and M3 Pro and the M3 Pro has more battery remaining at the end of the video: https://youtu.be/aQvsZQ3QBiU

Same for this video where they compare M1 Max, M2 Max and M3 Max: https://youtu.be/BWeuhxnWDl0

I'll re-test. I don't use the M3 often, so it could be something else like spotlight running in the background that's causing the drain.

FWIW, I've noticed Chrome uses considerably more power than Safari when watching Youtube - about 3 watts - when having one video playing in the foreground. Just to be aware in case you switch between them.

I'm seeing a bit better battery life in general on my 16" M3 Max than I did on my former 16" M1 Pro.

What browser are you using? Safari?

Is it draining or just not charging to 100% (optimized charging)?

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