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A comment on AMD Claims Arm ISA Doesn't Offer Efficiency Advantage over x86. Parent comment

Re:AMD Claims Arm ISA Doesn't Offer Efficiency Advantage ove... by txrx0000 on Tuesday September 09, 2025 @06:32AM (#45180102)
Pardon my loose choice of words regarding the Mac-like efficiency. I was referring to the fact that the battery life is comparable to the M3 in day-to-day use, as demonstrated at around the 5:00 mark in the third video I linked.

In the same video, they also measure perf/watt under heavy load, and it's close to the M1, but not the latest gen M4. I think that's pretty good considering it's a first gen product.

Regarding the discontinuation, it's still on shelves right now, but I'm not sure if there will be future generations. It would be awfully silly of them to discontinue it as it's the best non-Apple laptop chip you can buy right now if you care about efficiency.

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Re:AMD Claims Arm ISA Doesn't Offer Efficiency Advantage ove... by aurareturn on Tuesday September 09, 2025 @06:49AM (#45180234) 

  In the same video, they also measure perf/watt under heavy load, and it's close to the M1, but not the latest gen M4. I think that's pretty good considering it's a first gen product.
Which video and timestamp? Are you aware that LNL throttles heavily when on battery life?

On battery life, M1 is a whopping 1.5x faster in single thread.[0] That makes M4 2.47x faster when compared to LNL on battery.

So no, LNL is very far behind even M1. That's why there are no fanless LNL laptops.

[0]https://b2c-contenthub.com/wp-content/uploads/2024/09/Intel-...

[0]https://www.pcworld.com/article/2463714/tested-intels-lunar-...

[0]https://browser.geekbench.com/macs/macbook-air-late-2020

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Re:AMD Claims Arm ISA Doesn't Offer Efficiency Advantage ove... by txrx0000 on Tuesday September 09, 2025 @08:10AM (#45180827)
I suspect the throttling behavior has to more do with the power settings used during testing or OEM tuning on specific models.

https://www.youtube.com/watch?v=ymoiWv9BF7Q

In this video, they show the perf/watt curves at 8:30. And they show the on-battery vs on-wall performance at 18:35 across a wide variety of benchmarks, not just Geekbench. They used a Lenovo YOGA Air 15 on Window 11's "Balanced" power plan for their tests. The narrator specifically noted the Macbook-like on-battery performance.

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Re:AMD Claims Arm ISA Doesn't Offer Efficiency Advantage ove... by aurareturn on Tuesday September 09, 2025 @08:16AM (#45180899)
Reviewers always use max performance setting for benchmarks and then max battery life for battery tests. That's how people get tricked. When they actually buy the laptop and use it for themselves, they complain that it's slow when on battery life or hot/loud when plugged in.
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Re:AMD Claims Arm ISA Doesn't Offer Efficiency Advantage ove... by txrx0000 on Tuesday September 09, 2025 @08:33AM (#45181087)
They're not trying to trick you. In fact when they were measuring perf/watt, the Lunar Lake chip was disadvantaged against the Apple M-series because they had to run the SPEC 2017 tests on Ubuntu for the Lunar Lake chip, which has poorer tuning for it compared to Windows 11. You can see a footnote saying the compilation environment was Ubuntu 24.04 LTS on the bottom left corner of the frame when they show the perf/watt graphs.
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Re:AMD Claims Arm ISA Doesn't Offer Efficiency Advantage ove... by aurareturn on Tuesday September 09, 2025 @09:11AM (#45181474)
They are trying to trick you. All reviewers are told by Intel to run benchmarks in max performance mode and battery either in balanced or max efficiency mode. These modes will throttle. So the performance you're seeing in reviews aren't achievable in battery mode unless you're ok with drastically lower battery life.

Meanwhile, PCWorld is one of the few that actually ran benchmarks while on battery life - which is what people will experience.

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