The unsung heroes in the M2 Pro: the efficiency cores

[chris11]

Hi.

I've run a few tests on my new MBP 14'' with the low-end M2-Pro (10 core).

I'm particularly impressed with the efficiency cores!

In a compile test using clang to compile an Open Source project, I found
that doing a parallel build with the 4 efficiency cores takes ~ 6 times longer
than the same build with the performance cores, but uses just ~ 1/43 of the
average power (CPU power measured with powermetrics).

In other words, to complete the same task, the efficiency cores used just
14% of the energy the performance cores used.

Some more details are here:

Energy-efficient computing

Ok, so here’s yet another set of benchmarks on the new M2 Pro CPU. Apple has doubled the number of efficiency cores from 2 to 4 in the M2 family and this caught my …

1006.org

-- Chris

 

[sam_dean]

Hi.

I've run a few tests on my new MBP 14'' with the low-end M2-Pro (10 core).

I'm particularly impressed with the efficiency cores!

In a compile test using clang to compile an Open Source project, I found
that doing a parallel build with the 4 efficiency cores takes ~ 6 times longer
than the same build with the performance cores, but uses just ~ 1/43 of the
average power (CPU power measured with powermetrics).

In other words, to complete the same task, the efficiency cores used just
14% of the energy the performance cores used.

Some more details are here:

Energy-efficient computing

Ok, so here’s yet another set of benchmarks on the new M2 Pro CPU. Apple has doubled the number of efficiency cores from 2 to 4 in the M2 family and this caught my …

1006.org

-- Chris

Now imagine that 5nm process node part becoming a 3nm one by this time next year?

 

[throAU]

This goes back to M1 as well.

look how much of the work my efficiency cores are doing on M1 Pro.

Running the workload pictured.

 

[bobmans]

It's crazy what these E-cores are able to do with barely using any power.
For a lot of people a notebook with a M-lite chip with nothing more than a handful of efficiency cores and a couple of gpu-cores would have way more power than they need.

 

[throAU]

For sure.

The main reason im not on an air is the screen and speakers. They’re too good to pass up.

 

[sam_dean]

For sure.

The main reason im not on an air is the screen and speakers. They’re too good to pass up.

Rumor of a 15" MBA is doing its rounds. It may address your concerns.

 

[throAU]

Rumor of a 15" MBA is doing its rounds. It may address your concerns.

Unlikely as the air is a lower cost device.

It won’t get the hdr panel.

I’m sure it will work for many though; I just spend 8-10 plus hours most days using this thing and it is a tax deductible purchase for me so willing to pay for the screen.

 

[benwiggy]

The efficiency cores seem to be doing most of the heavy lifting in my Mini, where efficiency is less of a requirement.

 

[dmccloud]

What's fun is to use something like asitop in conjunction with powermetrics to get a graphical representation of CPU usage. This was just taken, with me running Terminal and Firefox on the machine at the time. The power draw is the part that still throws me for a loop, even over two years into the Apple Silicon era.

 

[throAU]

The power efficiency of the M series in general is crazy. I mean this is safari with 4 tabs open, Fantastical, Parcl, BitDefender, and a bunch of other stuff running in the background/menu bar.

CPU Power: 43 mW GPU Power: 4 mW ANE Power: 0 mW Combined Power (CPU + GPU + ANE): 47 mW **** GPU usage **** GPU active frequency: 402 MHz GPU active residency: 1.23% (389 MHz: 1.2% 486 MHz: 0% 648 MHz: 0% 778 MHz: .04% 972 MHz: 0% 1296 MHz: 0%) GPU requested frequency: (389 MHz: 1.2% 486 MHz: 0% 648 MHz: .04% 778 MHz: .00% 972 MHz: .00% 1296 MHz: 0%) GPU idle residency: 98.77% GPU Power: 4 mW


Combined CPU+GPU power of 0.047 of a watt!