[nbf_1995]

> Apple M2 (Linux/8gb/4c) This is an error on Phoronix's part. The M2 has 8 physical cores with no SMT which makes it 8c/8t. You can see all 8 cores in the die shots https://semianalysis.substack.com/p/apple-m2-die-shot-and-ar...

[GeekyBear]

>The M2 has 8 physical cores

4 performance cores and 4 efficiency cores.

[nbf_1995]

Correct. I should have specified in my comment

[adgjlsfhk1]

While it technically has 8 cores, you can only use 4 at a time, so it's in most cases more correct to think of it as having 4 cores.

[nbf_1995]

This is not the case. All 8 physical cores of the M1/2 can be utilized simultaneously, since each is a full physical core, independent of the others. The statement about only being able to use 4 at a time is true of threads, such as those found on SMT enabled processors that have core/thread counts like 4c/8t. In those systems, the threads share logic and decoding circuitry with each other, which would make your statement correct. You can see this in the M2 die shots. Both banks of 4 cores are in separate areas of the die. https://semianalysis.substack.com/p/apple-m2-die-shot-and-ar...

(edit): Granted 4 of the cores are lower powered "efficiency" cores, this is by no means equivalent to having just 4 cores

[olliej]

The hardware doesn’t have such a restriction, is there software/kernel issue you’re referring to?

[astrange]

No, they're thinking of how older ARM E-cores worked.

(aka big.LITTLE which is some strange branding.)