How the E and P cores in an M1 Max chip cope with the heavy system workload after login, but still give the user the scope to run apps immediately.
QoS
If apps control the Quality of Service, which sets how macOS allocates them to different processor cores in an M1 chip, how can we have any control?
When running some tasks confined to E cores, the original M1 chip from 2020 completes them significantly quicker than an on an M1 Pro. Here’s the detail.
Is it overhead from sandboxing, the file system, the throttling of I/O, or the limitations of the Efficiency cores? Is there anything a user can do?
Running processes at different Quality of Service affects their performance differently on Intel and M1 Macs. This explains what happens.
Although there doesn’t appear to be any straightforward way to run command tools or scripts only on Efficiency cores, there are ways and means.
We commonly suffer failures of the psychology of Mac performance, when system background tasks overwhelm the processor and bring the interface to a grinding halt
The Eclectic Light Company 