Virtual CPU cores are of one type, and QoS has no effect in virtualised macOS. This has consequences for both the host and guest macOS.
GCD
Many apps could benefit users of Apple silicon Macs by giving them controls over core use by their threads. Here’s how that can be done simply and effectively.
How you can use the taskpolicy command to confine all the threads of a process to the E cores, as a brake, but there’s no accelerator in macOS.
How can the two E cores in an M1 Pro or Max equal performance of the four in the original M1? Why does running two threads complete in half the time taken to run one?
Threads, GCD and core allocation in Apple silicon explained. How thread priority is baked into code, and how important it is to performance.
It’s a strange coincidence that Intel and Microsoft came up with similar hardware of P and E core types in a SoC, and identical terminology for thread allocation using QoS.
It delivers detailed weather forecasts for days in advance, and real-time manipulation of elaborate textured 3D models. But more mundane tasks may not get any quicker.
Time Machine backups are but one of 70-80 background services which are run by macOS dispatching systems. Here’s a list of some of the others.
When scheduled backups become irregular or stop, this affects much more than just Time Machine. This is what happens, and why you must restart.
How scheduling concurrent and background tasks using XPC Activity works, and compares with alternatives such as NSBackgroundActivityScheduler.