There’s evidence to suggest that original M1 Macs write more slowly to external SSDs in some configurations. Does this extend to later models with M1 Pro or Max chips?
M1 Max
Using a test of compressing a 1 GB file with AppleArchive, measurements of power used by core clusters show how efficient using the E cores really is.
Using CPU % or Energy values in Activity Monitor appears to show that running code on E cores is less efficient than on P cores. Don’t believe a word of it.
Which of the external disks tested can be used to boot from? Do they work reliably with Secure Boot? Could you boot from an external hard disk?
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?
From the 8 cores of the original M1 chip to the M1 Ultra’s 20, this is how macOS manages threads from apps, services and other code.
It’s limited to 5 Gb/s, giving read rates of about 400 MB/s and writes at about 430 MB/s. Fine for Time Machine backups, but bad with NVMe drives.
Which is faster, a MacBook Pro 16-inch with an M1 Pro, or a Mac Studio with an M1 Max? Tests cover P and E cores, Neural Engine, SSD and more.
There are two situations when M1 chips confine code to just one of their Performance cores: during startup, before the other cores are running, and when preparing an update.
Just how fast is a Mac Studio with an M1 Ultra? It all depends on the factors discussed here, with details of M1 series CPU performance.
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