6 ms·

Is there a tradeoff in terms of power consumption?

by skohan 5y ago

hajile 5y ago
In A15, Anandtech claims the Efficiency cores are 1/3 the performance, but 1/10 the power. They should be looking at (effectively) doubling the power consumption over M1 with just the CPUs and assuming they don't increase clockspeeds. Going from 8 to 16 or 32 GPU cores is another massive power increase.
- barelysapient 5y ago
  I wonder if Apple will give us a 'long-haul' mode where the system is locked to only the energy efficient cores and settings. I us developer types would love a computer that survives 24 hours on battery.
  - modulusshift 5y ago
    macOS Monterey coming out on the 25th has a new Low Power Mode feature that may do just that. That said, these Macs are incredibly efficient for light use, you may already get 24 hrs of battery life with your workload. Not counting screen off time.
    - sulam 5y ago
      Yes, it depends on what you're doing, but if you can watch 21 hours of video, many people will be able to do more than 24 hours of development.
      - willseth 5y ago
        Video playback is accelerated by essentially custom ASIC processing built into the CPU, so it's one of the most efficient things you can do now. Most development workloads are far more compute intensive.
        rgrs 5y ago
        Might be less computationally expensive. But video playback constantly refreshes screen which uses up battery
        foepys 5y ago
        Did Electron fix the 60Hz (or rather current screen refresh rate) cursor blinking? Otherwise I don't see many web devs getting a lot of runtime in.
        barelysapient 5y ago
        That's actually a curious question, I wonder what the most energy efficient dev tool is. Can't imagine its VScode. Maybe plain terminal with VIM?
        willseth 5y ago
        This is true, but it's not worst case by far. Most video is 24 or 30 fps, so about half the typical 60 hz refresh rate. Still a nice optimization path for video. I'm not sure what effect typing in an editor will have on screen refresh, but if the Electron issue is any indication, it's probably complicated.
        kube-system 5y ago
        I know everyone's use case is different, but most of my development workload is 65% typing code into a text editor and 35% running it. I'm not continually pegging the CPU, just intermittently, in which case the existence of low power cores help a lot. The supposed javascript acceleration in the M1 has seemed to really speed up my workloads too.
        jhugo 5y ago
        I get about 14-16 hours out of my M1 MacBook Air doing basically full-time development (browser, mail client, Slack, text editor & terminal open, and compiling code periodically).
  - deleted 5y ago
    [deleted]
ksec 5y ago
Yes. But the 14" and 16" has larger battery than 13" MacBook Pro or Air. And they were designed for performance, so two less EE core doesn't matter as much. It is also important to note, despite the name with M1, we dont know if the CPU core are the same as the one used in M1 / A14. Or did they used A15 design where the energy efficient core had significant improvement. Since the Video Decoder used in M1 Pro and Max seems to be from A15, the LPDDR5 is also a new memory controller.
cbarrick 5y ago
In the power/performance curves provided by Apple, they imply that the Pro/Max provides the same level of performance at a slightly lower power consumption than the original M1. But at the same time, Apple isn't providing any hard data or explaining their methodology. I dunno how much we should be reading into the graphs. /shrug
- mlindner 5y ago
  I think you misread the graph. https://www.apple.com/newsroom/images/product/mac/standard/Apple_M1-Pro-M1-Max_CPU-Performance_10182021_big.jpg.large_2x.jpg https://www.apple.com/newsroom/images/product/mac/standard/A... The graph there shows that the new chip is higher power usage at all performance levels.
  - derefr 5y ago
    Not all; it looks like the M1 running full-tilt is slightly less efficient for the same perf than the M1 Pro/Max. (I.e., the curves intersect.)
    - jrk 5y ago
      Yes, but only at the very extreme. It's normal that a high core count part at low clocks has higher efficiency (perf/power) at a given performance level than a low core count part at high clocks, since power grows super-linearly with clock speed (decreasing efficiency). But notably they've tuned the clock/power regime of the M1 Pro/Max CPUs that the crossover region here is very small.
- eyelidlessness 5y ago
  I think this is pretty easy to math: M1 has 2x the efficiency cores of these new models. Those cores do a lot of work in measured workloads that will sometimes be scheduled on performance cores instead. The relative performance and efficiency lines up pretty well if you assume that a given benchmark is utilizing all cores.
gzer0 5y ago
> M1 Pro delivers up to 1.7x more CPU performance at the same power level and achieves the PC chip’s peak performance using up to 70 percent less power Uses less power
- mlindner 5y ago
  That's compared to the PC chips, not M1. M1 uses less power at same performance levels. https://www.apple.com/newsroom/images/product/mac/standard/Apple_M1-Pro-M1-Max_CPU-Performance_10182021_big.jpg.large_2x.jpg https://www.apple.com/newsroom/images/product/mac/standard/A...
SpelingBeeChamp 5y ago
Huge, apparently. I just spent a bit over $7,000 for a top-spec model and was surprised to read that it comes with a 140 watt power adapter. Prior to my current M1 MBP, my daily driver was a maxed-out 16" MBP. It's a solid computer, but it functions just as well as a space heater. And its power adapter is only 100 watts.
- jerrysievert 5y ago
  the power supply is for charging the battery faster. the new magsafe 3 system can charge with more wattage than usb-c, as per the announcement. usb-c max wattage is 100 watts, which was the previous limiting factor for battery charge.
  - robert_foss 5y ago
    USB-C 3.1 PD delivers up to 240watts.
    - aetherspawn 5y ago
      That's with 2 connectors right? I have a Dell Precision 3760 and the one connector charging mode is limited to around 90W. With two connectors working in tandem (they snap together), it's 180W. The connectors never get remotely warm .. in fact under max charge rate they're consistently cool to touch, so I've always thought that it could probably be increased a little bit with no negative consequences.
      - wlesieutre 5y ago
        Single connector, the 3.1 spec goes up to 5A at 48V. You need new cables with support for the higher voltages, but your "multiple plugs for more power" laptop is exactly the sort of device it's designed for. It was announced earlier this year, so not in wide use yet. PDF warning: https://usb.org/sites/default/files/2021-05/USB%20PG%20USB%20PD%203.1%20DevUpdate%20Announcement_FINAL.pdf https://usb.org/sites/default/files/2021-05/USB%20PG%20USB%2...

Is there a tradeoff in terms of power consumption?

by skohan 5y ago

Is there a tradeoff in terms of power consumption?

In A15, Anandtech claims the Efficiency cores are 1/3 the performance, but 1/10 the power. They should be looking at (effectively) doubling the power consumption over M1 with just the CPUs and assuming they don't increase clockspeeds. Going from 8 to 16 or 32 GPU cores is another massive power increase.

barelysapient 5y ago
I wonder if Apple will give us a 'long-haul' mode where the system is locked to only the energy efficient cores and settings. I us developer types would love a computer that survives 24 hours on battery.
- modulusshift 5y ago
  macOS Monterey coming out on the 25th has a new Low Power Mode feature that may do just that. That said, these Macs are incredibly efficient for light use, you may already get 24 hrs of battery life with your workload. Not counting screen off time.
  - sulam 5y ago
    Yes, it depends on what you're doing, but if you can watch 21 hours of video, many people will be able to do more than 24 hours of development.
    - willseth 5y ago
      Video playback is accelerated by essentially custom ASIC processing built into the CPU, so it's one of the most efficient things you can do now. Most development workloads are far more compute intensive.
      - rgrs 5y ago
        Might be less computationally expensive. But video playback constantly refreshes screen which uses up battery
        foepys 5y ago
        Did Electron fix the 60Hz (or rather current screen refresh rate) cursor blinking? Otherwise I don't see many web devs getting a lot of runtime in.
        barelysapient 5y ago
        That's actually a curious question, I wonder what the most energy efficient dev tool is. Can't imagine its VScode. Maybe plain terminal with VIM?
        willseth 5y ago
        This is true, but it's not worst case by far. Most video is 24 or 30 fps, so about half the typical 60 hz refresh rate. Still a nice optimization path for video. I'm not sure what effect typing in an editor will have on screen refresh, but if the Electron issue is any indication, it's probably complicated.
      - kube-system 5y ago
        I know everyone's use case is different, but most of my development workload is 65% typing code into a text editor and 35% running it. I'm not continually pegging the CPU, just intermittently, in which case the existence of low power cores help a lot. The supposed javascript acceleration in the M1 has seemed to really speed up my workloads too.
      - jhugo 5y ago
        I get about 14-16 hours out of my M1 MacBook Air doing basically full-time development (browser, mail client, Slack, text editor & terminal open, and compiling code periodically).
- deleted 5y ago
  [deleted]

ksec 5y ago

Yes. But the 14" and 16" has larger battery than 13" MacBook Pro or Air. And they were designed for performance, so two less EE core doesn't matter as much. It is also important to note, despite the name with M1, we dont know if the CPU core are the same as the one used in M1 / A14. Or did they used A15 design where the energy efficient core had significant improvement. Since the Video Decoder used in M1 Pro and Max seems to be from A15, the LPDDR5 is also a new memory controller.

cbarrick 5y ago

In the power/performance curves provided by Apple, they imply that the Pro/Max provides the same level of performance at a slightly lower power consumption than the original M1. But at the same time, Apple isn't providing any hard data or explaining their methodology. I dunno how much we should be reading into the graphs. /shrug

mlindner 5y ago
I think you misread the graph. https://www.apple.com/newsroom/images/product/mac/standard/Apple_M1-Pro-M1-Max_CPU-Performance_10182021_big.jpg.large_2x.jpg https://www.apple.com/newsroom/images/product/mac/standard/A... The graph there shows that the new chip is higher power usage at all performance levels.
- derefr 5y ago
  Not all; it looks like the M1 running full-tilt is slightly less efficient for the same perf than the M1 Pro/Max. (I.e., the curves intersect.)
  - jrk 5y ago
    Yes, but only at the very extreme. It's normal that a high core count part at low clocks has higher efficiency (perf/power) at a given performance level than a low core count part at high clocks, since power grows super-linearly with clock speed (decreasing efficiency). But notably they've tuned the clock/power regime of the M1 Pro/Max CPUs that the crossover region here is very small.
eyelidlessness 5y ago
I think this is pretty easy to math: M1 has 2x the efficiency cores of these new models. Those cores do a lot of work in measured workloads that will sometimes be scheduled on performance cores instead. The relative performance and efficiency lines up pretty well if you assume that a given benchmark is utilizing all cores.

gzer0 5y ago

> M1 Pro delivers up to 1.7x more CPU performance at the same power level and achieves the PC chip’s peak performance using up to 70 percent less power Uses less power

mlindner 5y ago
That's compared to the PC chips, not M1. M1 uses less power at same performance levels. https://www.apple.com/newsroom/images/product/mac/standard/Apple_M1-Pro-M1-Max_CPU-Performance_10182021_big.jpg.large_2x.jpg https://www.apple.com/newsroom/images/product/mac/standard/A...

SpelingBeeChamp 5y ago

Huge, apparently. I just spent a bit over $7,000 for a top-spec model and was surprised to read that it comes with a 140 watt power adapter. Prior to my current M1 MBP, my daily driver was a maxed-out 16" MBP. It's a solid computer, but it functions just as well as a space heater. And its power adapter is only 100 watts.

jerrysievert 5y ago
the power supply is for charging the battery faster. the new magsafe 3 system can charge with more wattage than usb-c, as per the announcement. usb-c max wattage is 100 watts, which was the previous limiting factor for battery charge.
- robert_foss 5y ago
  USB-C 3.1 PD delivers up to 240watts.
  - aetherspawn 5y ago
    That's with 2 connectors right? I have a Dell Precision 3760 and the one connector charging mode is limited to around 90W. With two connectors working in tandem (they snap together), it's 180W. The connectors never get remotely warm .. in fact under max charge rate they're consistently cool to touch, so I've always thought that it could probably be increased a little bit with no negative consequences.
    - wlesieutre 5y ago
      Single connector, the 3.1 spec goes up to 5A at 48V. You need new cables with support for the higher voltages, but your "multiple plugs for more power" laptop is exactly the sort of device it's designed for. It was announced earlier this year, so not in wide use yet. PDF warning: https://usb.org/sites/default/files/2021-05/USB%20PG%20USB%20PD%203.1%20DevUpdate%20Announcement_FINAL.pdf https://usb.org/sites/default/files/2021-05/USB%20PG%20USB%2...