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.
QoS
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 