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0 pointsaurareturn7mo ago0 comments

  All that to say: M1 is pretty fast, but the reason the battery life is better has to do with everything other than the CPU cores. That's what AMD and Intel are missing.

This isn't true. Yes, uncore power consumption is very important but so is CPU load efficiency. The faster the CPU can finish a task, the faster it can go back to sleep, aka race to sleep.

Apple Silicon is 2-4x more efficient than AMD and Intel CPUs during load while also having higher top end speed.

Another thing that makes Apple laptops feel way more efficient is that they use a true big.Little design while AMD and Intel's little cores are actually designed for area efficiency and not power efficiency. In the case of Intel, they stuff as many little cores as possible to win MT benchmarks. In real world applications, the little cores are next to useless because most applications prefer a few fast cores over many slow cores.

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yaro3307mo ago

> Apple Silicon is 2-4x more efficient than AMD and Intel CPUs during load while also having higher top end speed.

This is false, in cross platform tasks it's on par if not worse than latest X86 arches. As others pointed out: 2.5h in gaming is about what you'd expect from a similarly built X86 machine.

They are willing due to lower idle and low load consumption, which they achieve by integrating everything as much as possible - something that's basically impossible for AMD and Intel.

> The faster the CPU can finish a task, the faster it can go back to sleep, aka race to sleep.

May have been true when CPU manufacturers left a ton of headroom on the V/F curve, but not really true anymore. Zen 4 core's power draw shoots up sharply pass 4.6 GHz and nearly triples when you approach 5.5 GHz (compared to 4.6), are you gonna complete the task 3 times faster at 5.5 GHz?

aurareturnOP7mo ago

  This is false, in cross platform tasks it's on par if not worse than latest X86 arches.

This is Cinebench 2024, a cross platform application: https://imgur.com/a/yvpEpKF

  They are willing due to lower idle and low load consumption, which they achieve by integrating everything as much as possible - something that's basically impossible for AMD and Intel.

Weird because LNL achieved similar idle wattage as Apple Silicon.[0] Why do you say it's impossible?

  May have been true when CPU manufacturers left a ton of headroom on the V/F curve, but not really true anymore. Zen 4 core's power draw shoots up sharply pass 4.6 GHz and nearly triples when you approach 5.5 GHz (compared to 4.6), are you gonna complete the task 3 times faster at 5.5 GHz?

Honestly not sure how your statement is relevant.

[0]https://www.notebookcheck.net/Dell-XPS-13-9350-laptop-review...

atwrk7mo ago

This is Cinebench 2025, a cross platform application: https://imgur.com/a/yvpEpKF

You sure like that table, don't you? Trying to find the source of that blender numbers, I came across many reddit posts of you with that exact same table. Sadly those also don't have a source - the are not from the notebookcheck source.

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yaro3307mo ago

> Weird because LNL achieved similar idle wattage as Apple Silicon.[0] Why do you say it's impossible?

And where is LNL now? How's the company that produced it? Even under Pat Gelsinger they said that LNL is a one off and they're not gonna make any more of them. It's commercially infeasible.

> Honestly not sure how your statement is relevant.

How is you bringing up synthetics relevant to race to idle?

Regardless, a number of things can be done on Strix Halo to improve the performance, first would be switching to some optimized Linux distro, or at least the kernel. That would claw back 5-20% depending on the task. It would also improve single core efficiency, I've seen my 7945hx drop from 14-15w idle on Windows to about 7-8 on Linux, because Windows likes to jerk off the CCDs non stop and throw the tasks around willy nilly which causes the second CCD and I/O die to never properly idle.

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ben-schaaf7mo ago

> This is Cinebench 2024, a cross platform application: https://imgur.com/a/yvpEpKF

Cool, now compare M1 to AI 340. The AI 340 has slightly better single core and better multi-core. If battery life was all about race to idle like you claim then the AI 340 should be better than the M1.

See also Snapdragon X Elite, which is significantly slower than the AI 340, uses more power under load, so in total has much less efficient cores, and yet still beats the AI 340 on battery life.

williamDafoe7mo ago

I did mips per watt calculations in 2017 and Apple (A10 i think) was 2-3x better than intel. See "how to build a computer" by donald gillies (slideshare slides). I was shocked, i didnt expect this at all!

jandrewrogers7mo ago

> Apple Silicon is 2-4x more efficient than AMD and Intel CPUs during load while also having higher top end speed.

This is not true. For high-throughput server software x86 is significantly more efficient than Apple Silicon. Apple Silicon optimizes for idle states and x86 optimizes for throughput, which assumes very different use cases. One of the challenges for using x86 in laptops is that the microarchitectures are server-optimized at their heart.

ARM in general does not have the top-end performance of x86 if you are doing any kind of performance engineering. I don't think that is controversial. I'd still much rather have Apple Silicon in my laptop.

aurareturnOP7mo ago

  For high-throughput server software x86 is significantly more efficient than Apple Silicon.

In the server space, x86 has the highest performance right now. Yes. That's true. That's also because Apple does not make server parts. Look for Qualcomm to try to win the server performance crown in the next few years with their Oryon cores.

That said, Graviton is at least 50% of all AWS deployments now. So it's winning vs x86.

  ARM in general does not have the top-end performance of x86 if you are doing any kind of performance engineering. I don't think that is controversial.

I think you'll have to define what top-end means and what performance engineering means.

ksec7mo ago

I dont think the point Amazon uses ARM was about performance but purely cost optimisation. At one point, nearly 40% of Intel's server revenue was coming from Amazon. They just figure it out at their scale it would be cheaper to do it themselves.

But I am purely guessing ARM has risen their price per core so it makes less financial sense to do a yearly update on CPU. They are also going into Server CPU business meaning they now have some incentives to keep it all to themselves. Which makes the Nvidia moves really smart as they decided to go for the ISA licences and do it by themselves.

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yaro3307mo ago

> Apple Silicon is 2-4x more efficient than AMD and Intel CPUs during load while also having higher top end speed.

This is false, in cross platform tasks it's on par if not worse than latest X86 arches. As others pointed out: 2.5h in gaming is about what you'd expect from a similarly built X86 machine.

They are willing due to lower idle and low load consumption, which they achieve by integrating everything as much as possible - something that's basically impossible for AMD and Intel.

> The faster the CPU can finish a task, the faster it can go back to sleep, aka race to sleep.

aurareturnOP7mo ago

  This is false, in cross platform tasks it's on par if not worse than latest X86 arches.

This is Cinebench 2024, a cross platform application: https://imgur.com/a/yvpEpKF

  They are willing due to lower idle and low load consumption, which they achieve by integrating everything as much as possible - something that's basically impossible for AMD and Intel.

Weird because LNL achieved similar idle wattage as Apple Silicon.[0] Why do you say it's impossible?

  May have been true when CPU manufacturers left a ton of headroom on the V/F curve, but not really true anymore. Zen 4 core's power draw shoots up sharply pass 4.6 GHz and nearly triples when you approach 5.5 GHz (compared to 4.6), are you gonna complete the task 3 times faster at 5.5 GHz?

Honestly not sure how your statement is relevant.

[0]https://www.notebookcheck.net/Dell-XPS-13-9350-laptop-review...

atwrk7mo ago

This is Cinebench 2025, a cross platform application: https://imgur.com/a/yvpEpKF

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yaro3307mo ago

> Weird because LNL achieved similar idle wattage as Apple Silicon.[0] Why do you say it's impossible?

And where is LNL now? How's the company that produced it? Even under Pat Gelsinger they said that LNL is a one off and they're not gonna make any more of them. It's commercially infeasible.

> Honestly not sure how your statement is relevant.

How is you bringing up synthetics relevant to race to idle?

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ben-schaaf7mo ago

> This is Cinebench 2024, a cross platform application: https://imgur.com/a/yvpEpKF

See also Snapdragon X Elite, which is significantly slower than the AI 340, uses more power under load, so in total has much less efficient cores, and yet still beats the AI 340 on battery life.

williamDafoe7mo ago

jandrewrogers7mo ago

> Apple Silicon is 2-4x more efficient than AMD and Intel CPUs during load while also having higher top end speed.

aurareturnOP7mo ago

  For high-throughput server software x86 is significantly more efficient than Apple Silicon.

That said, Graviton is at least 50% of all AWS deployments now. So it's winning vs x86.

  ARM in general does not have the top-end performance of x86 if you are doing any kind of performance engineering. I don't think that is controversial.

I think you'll have to define what top-end means and what performance engineering means.

ksec7mo ago

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