4 ms·

5900HX TDP: 35-80W depending on boost setting. Most gaming laptops set it at 60W+. M2 TDP: 20W

kimixa 4y ago
Power use tends to scale non-linearly past a point - disabling turbo modes would likely significantly reduce the peak power use, and ~18% performance differenceis pretty big buffer to lose. The 6850u also beats it rather comprehensively according to those same results, and that's only 18-25w. Really, you'd need everything power normalized, and even the rest of the hardware and software used normalized to compare "just" the CPU, which is pretty much impossible due to Apple and their vertical integration - which is often a strength in tests like this.
KaoruAoiShiho 4y ago
The 6850U is comparable in power use and still has a big perf gap against the M2 in mosts tests. Though there are some tests where the M2 leads with a big gap too so maybe it comes down to software in a lot of these. Still it seems to me like Apple is not leading.
- ceeplusplus 4y ago
  It is not, the laptop tested with the 6850U has a 30W PL2 and 50W PL1.
  - KaoruAoiShiho 4y ago
    I don't know where you got those numbers. That it can sometimes hit higher peaks is a good thing and shouldn't be counted against it. https://www.phoronix.com/review/ryzen7-6850u-acpi/6 https://www.phoronix.com/review/ryzen7-6850u-acpi/6 According to this it should be an average of 19.3 Watts with a peak of 31.85 Watts. Apple also exceeds the stated tdp during peaks as well but we don't have that information atm. And remember there's a 14% perf gap between the two. My purpose isn't really to say AMD is definitely better since apple still probably takes the win in overall product, I think the MBA is thinner and that's important to me. But it's to show that x86 isn't behind in performance and that you're not making sacrifices in that department to maintain software compatibility with the x86 ecosystem. No sacrifices imo, AMD is just fine.
    - ceeplusplus 4y ago
      That average is over the entire benchmarking suite, including single thread tests and when tests are loading from disk or otherwise not fully saturating the CPU. Some of those benchmarks in that power consumption number are GPU only! Take a look at the AOM AV1 power consumption graph (https://openbenchmarking.org/result/2208044-NE-6850U700026&sgm=1&sor https://openbenchmarking.org/result/2208044-NE-6850U700026&s...), it clearly displays huge drops when the test stops running. The CPU is turboing to 30 watts in 75% of the run. If you use the 15W hard cap performance numbers (low power mode), performance drops 20-40%. > Apple also exceeds the stated tdp during peaks as well but we don't have that information atm We actually do. Notebookcheck recorded 20W usage on a peak MT load (https://www.notebookcheck.net/Apple-MacBook-Air-M2-Entry-Review-A-very-good-but-too-expensive-daily-MacBook.636637.0.html#toc-5 https://www.notebookcheck.net/Apple-MacBook-Air-M2-Entry-Rev...). The MBA is fanless so it's physically impossible for it to substantially exceed that amount without frying your lap. > And remember there's a 14% perf gap between the two Like I said, power is not equal at all. > x86 isn't behind in performance and that you're not making sacrifices in that department to maintain software compatibility with the x86 ecosystem Comparing the lowest end chip from one vendor to the highest end chip from another is not exactly a great look. Especially when the Arm chip is basically matching the x86 one while having only a few years of software optimization work.
      - smoldesu 4y ago
        One could argue that the Ryzen's biggest pitfall is that it hasn't adopted a big.LITTLE configuration yet. Alder Lake keeps it's thirsty TDPs while staying relatively respectful of your temps and battery life. It's not quite as granular as Apple's core clusters, but the work with Thread Director is a promising start. Seeing AMD push heterogeneous systems so far down the roadmap virtually guarantees that they won't get Apple-level power efficiency for a while. On the bright side, AMD has carte-blanche to design whatever they want. Not only can they one-up Intel by implementing core clusters, but they could also one-up Apple by adding power management per-logical-core, or some weird chiplet optimizations. The sky is the limit, really.
        4y ago
- 2muchcoffeeman 4y ago
  >Unfortunately for testing, as mentioned, right now there is no Linux driver exposing the M2 SoC power consumption under Linux. Hopefully this will be addressed in time but unfortunately meant not being able to deliver any accurate performance-per-Watt / power consumption benchmarks in this article. But when such support does come, it will likely show the M2 indeed delivering much better power efficiency than the Intel and AMD laptops tested. Even under demanding multi-threaded workloads, the M2 MacBook Air was not nearly as warm as the other laptops tested. It's a night and day difference of the M2 MacBook Air still being cool to warm compared to the likes of other notebooks like especially Dell XPS laptops that get outright hot under load. The power consumption metrics should also be more useful/relevant once Linux has working M1/M2 GPU support in place too. I mean, you shove a fan on the M2 and it beats itself...

Power use tends to scale non-linearly past a point - disabling turbo modes would likely significantly reduce the peak power use, and ~18% performance differenceis pretty big buffer to lose. The 6850u also beats it rather comprehensively according to those same results, and that's only 18-25w. Really, you'd need everything power normalized, and even the rest of the hardware and software used normalized to compare "just" the CPU, which is pretty much impossible due to Apple and their vertical integration - which is often a strength in tests like this.

KaoruAoiShiho 4y ago

The 6850U is comparable in power use and still has a big perf gap against the M2 in mosts tests. Though there are some tests where the M2 leads with a big gap too so maybe it comes down to software in a lot of these. Still it seems to me like Apple is not leading.

ceeplusplus 4y ago
It is not, the laptop tested with the 6850U has a 30W PL2 and 50W PL1.
- KaoruAoiShiho 4y ago
  I don't know where you got those numbers. That it can sometimes hit higher peaks is a good thing and shouldn't be counted against it. https://www.phoronix.com/review/ryzen7-6850u-acpi/6 https://www.phoronix.com/review/ryzen7-6850u-acpi/6 According to this it should be an average of 19.3 Watts with a peak of 31.85 Watts. Apple also exceeds the stated tdp during peaks as well but we don't have that information atm. And remember there's a 14% perf gap between the two. My purpose isn't really to say AMD is definitely better since apple still probably takes the win in overall product, I think the MBA is thinner and that's important to me. But it's to show that x86 isn't behind in performance and that you're not making sacrifices in that department to maintain software compatibility with the x86 ecosystem. No sacrifices imo, AMD is just fine.
  - ceeplusplus 4y ago
    That average is over the entire benchmarking suite, including single thread tests and when tests are loading from disk or otherwise not fully saturating the CPU. Some of those benchmarks in that power consumption number are GPU only! Take a look at the AOM AV1 power consumption graph (https://openbenchmarking.org/result/2208044-NE-6850U700026&sgm=1&sor https://openbenchmarking.org/result/2208044-NE-6850U700026&s...), it clearly displays huge drops when the test stops running. The CPU is turboing to 30 watts in 75% of the run. If you use the 15W hard cap performance numbers (low power mode), performance drops 20-40%. > Apple also exceeds the stated tdp during peaks as well but we don't have that information atm We actually do. Notebookcheck recorded 20W usage on a peak MT load (https://www.notebookcheck.net/Apple-MacBook-Air-M2-Entry-Review-A-very-good-but-too-expensive-daily-MacBook.636637.0.html#toc-5 https://www.notebookcheck.net/Apple-MacBook-Air-M2-Entry-Rev...). The MBA is fanless so it's physically impossible for it to substantially exceed that amount without frying your lap. > And remember there's a 14% perf gap between the two Like I said, power is not equal at all. > x86 isn't behind in performance and that you're not making sacrifices in that department to maintain software compatibility with the x86 ecosystem Comparing the lowest end chip from one vendor to the highest end chip from another is not exactly a great look. Especially when the Arm chip is basically matching the x86 one while having only a few years of software optimization work.
    - smoldesu 4y ago
      One could argue that the Ryzen's biggest pitfall is that it hasn't adopted a big.LITTLE configuration yet. Alder Lake keeps it's thirsty TDPs while staying relatively respectful of your temps and battery life. It's not quite as granular as Apple's core clusters, but the work with Thread Director is a promising start. Seeing AMD push heterogeneous systems so far down the roadmap virtually guarantees that they won't get Apple-level power efficiency for a while. On the bright side, AMD has carte-blanche to design whatever they want. Not only can they one-up Intel by implementing core clusters, but they could also one-up Apple by adding power management per-logical-core, or some weird chiplet optimizations. The sky is the limit, really.
      - 4y ago
2muchcoffeeman 4y ago
>Unfortunately for testing, as mentioned, right now there is no Linux driver exposing the M2 SoC power consumption under Linux. Hopefully this will be addressed in time but unfortunately meant not being able to deliver any accurate performance-per-Watt / power consumption benchmarks in this article. But when such support does come, it will likely show the M2 indeed delivering much better power efficiency than the Intel and AMD laptops tested. Even under demanding multi-threaded workloads, the M2 MacBook Air was not nearly as warm as the other laptops tested. It's a night and day difference of the M2 MacBook Air still being cool to warm compared to the likes of other notebooks like especially Dell XPS laptops that get outright hot under load. The power consumption metrics should also be more useful/relevant once Linux has working M1/M2 GPU support in place too. I mean, you shove a fan on the M2 and it beats itself...