New Mac Mini having better performance to external SSD?

[CLS7]

I have plans to upgrade to the new Mac Mini (M1X or M2) when it releases, hopefully this year.

I have heard that there are performance issues with external SSDs connected to the Mac Mini M1, that it only give up to 350MB/s and this is a performance limit on M1-macs. Is this true?

 

[Realityck]

I have plans to upgrade to the new Mac Mini (M1X or M2) when it releases, hopefully this year.

I have heard that there are performance issues with external SSDs connected to the Mac Mini M1, that it only give up to 350MB/s and this is a performance limit on M1-macs. Is this true?

M1 Mac mini supports:

• Two USB-A ports (up to 5Gb/s)
• Two Thunderbolt 3/USB 4 ports (up to 40Gb/s), they also can do USB 3.1 Gen 2 (up to 10Gb/s)

So if you were to use a DIY NVme m.2 external SSD with TB3/USB4 interface it would do up to reads 2600MB/s, a bit less with writes.
If you go to use the USB-A ports then that would drop to 540 MB/s, and USB 3.1 Gen 2 would be reads 1,050 MB/s, writes up to 1,000 MB/s.

 

[joevt]

If you go to use the USB-A ports then that would drop to 540 MB/s, and USB 3.1 Gen 2 would be reads 1,050 MB/s, writes up to 1,000 MB/s.

I think you mean 450 MB/s since USB 3.0 is 5 Gbps x 8b/10b = 4 Gbps = 500 MB/s.
M1 Macs have slower than expected USB performance so 1000 MB/s is probably a little high.
There are some issues discussed in:
https://forums.macrumors.com/thread...ally-10gb-s-also-definitely-not-usb4.2269777/

 

[verdejt]

This is what I got with my Samsung T7 plugged into the thunderbolt port. This was a 5gb test.