USB 3.1 Gen 2 drops to 5Gbps on M1 Mac mini

Are you connecting to one of the USB-C ports? The USB-A ports are only 5 Gb/s.

Mac mini (M1, 2020) - Technical specifications

"Two Thunderbolt / USB 4 ports with support for: 

DisplayPort

Thunderbolt 3 (up to 40 Gb/s)

USB 3.1 Gen 2 (up to 10 Gb/s)

Thunderbolt 2, HDMI, DVI, and VGA supported using adapters (sold separately)

Two USB-A ports (up to 5 Gb/s)"

The 2018 Mac mini ports are the same speeds, but you may not have noticed since the computer was slower.

Peter Wargo wrote:

from what I can read the ports on the M1 Mini should support USB 3.1 Gen 2 at the full 10Gbps speed.

They do, when you use the USB4 ports.

When you use the USB-A ports you get 5Gbps.

My results comparing 2020 M1 MBP vs 2019 Intel MBP (Both machines on Big Sur 11.1) :

Samsung T5: 360 MB/s vs 475 MB/s

Sandisk Extreme: 340 MB/s vs 475 MB/s

Crucial X8: 735 MB/s vs 930 MB/s

Sabrent NVMe Enclosure: 515 MB/s vs 950 MB/s

Sabrent XTRM-Q Thunderbolt 3: 1750 MB/s write 2550 read Vs 1630 write 2350 read

Thunderbolt 3 drive is the only one performing better on M1 chip.

USB 3.1 gen1 and gen2 were running around 30% slower on M1 machine then on Intel.

In the case of Sabrent gen 2 Enclosure almost 45% slower.

What could be the conclusions ? Controller issue ?

The Sabrent XTRM-Q came with a Thunderbolt 3 cable.

Try using that Thunderbolt 3 cable with the USB-C drives and retest.

Some have seen significant improvements using a TB3 cable

instead of USB-C on the M1 Macs.

woodmeister50 wrote:

FWIW, OWC has released a new TB/USB-C 4 0.8 meter cable

that they tout as lab tested and certified to work with all

flavors of TB and USB devices with USB-C interfaced.

It is priced significantly lower than the Apple TB3 cable:

https://eshop.macsales.com/item/OWC/CBLTB4C0.8M/

That won't make any difference.

I can confirm there is some kind of issue with either the software or hardware on the M1 Mac. I have the newest OWC Thunderbolt 4 dock and cable and it drops to 150 MB/s with both of my new SansDisk drives that get 900+ MB/s when attached directly to my M1 Mac, but less than 600 MB/s (5 Gbps) through any Thunderbolt dock I've tried: OWC TB4, AKiTiO TB3 (now owned by OWC) and the popular CalDigit TS3.

I've also read that some people with the Samsung T5 get the opposite results where they get max speeds through a dock but not when attached directly to their M1 Mac.

This is not a cable issue. I have a dozen 10 Gbps UCB-C cables and 1x OWC Thunderbolt 4 (passive) cable, 1x CableMatters Thunderbolt 4 (active) cable and 3x Thunderbolt 3 cables from a half-dozen manufactures that came with my TB/USB-C devices and the results are all the same.

Oddly enough, the OWC Thunderbolt 4 dock gets 600 MB/s with my SansDisk SSD's to my 2013 MBP over TB1 vs 150 MB/s with my M1 Mac through the same dock.

Whatever this problem is, it appears to be related to the M1 or Big Sur.

trevoz wrote:

> Looks to me like certain chipsets are up to the task whereas others get confused and drop to 5.

Equally, the M1 SoC may not be up to the task of properly negotiating the link speed, gets confused and drops to 5 Gbps....

The M1 does not negotiate the connections. There are "brand new" Intel

thunderbolt4/USB4 chips that do the actual communication and negotiating

in all of the M1 Macs and the M1 chips interface with them..

It is possible that it is these chips that are the culprit. Unfortunately,

so far Apple is the only one "in the wild" that are using these Intel chips at

the moment. It is also possible that it is the firmware that is not configuring these

chips properly or there is a bug in the Intel configuration process.

Personally, while a "one interface fits all approach" is desirable, it also increases

the complexity exponentially in terms of making everything play together

making debugging a bit difficult, especially with huge backward compatibility/interoperability

(USB4, USB 3.2, USB 3.1 Gen 2, USB 3.1 Gen 1, USB3, USB 2, USB 1, TB4, TB3, TB2, TB1,

Power Delivery, DisplayPort 1.4, DisplayPort 1.2, DisplayPort 1.0) and the infinite number

of types of devices that can connect to each to the USB-C port these standards.

I think this is common problem of M1 baseds Macs. I just found that my Tb3 external drive has very unstable speed. Jumping between 500 and 2100 for write and 500-2400 for read. When I test same drive on Intel based MacBook Pro I see full speed and zero drops! So my conclusion, TB4/USB4 on M1 are very bad. Could be software issue that can be fixed by Apple, but did you ever see Apple to confirm that they screwed up something and going to fix it?

Could also be a hardware issue you cannot fix by update.

Here is a speed on my Yottamaster TB3 enclosure on M1

and this is my (broken on write speed) T7. Ignore write speed, drive is broken and already on its way to Samsung, but read speed on T7 should/must be near 1000, not 600-700

I’ve read the thread, it’s just more people reporting the issue and testing various chipsets. This isn’t “retro compatibility”, USB 3.1 Gen 2 at 10Gb/s is a modern and current USB interface. It was plainly advertised, and still is, on Apple’s website and marketing material. This is a bug in their hardware or firmware, plain and simple. To fault the user in this case is absurd.

This issue is related to the new M1 chip and apples to all Macs running this hardware. It needs to be fixed by Apple. My NVME drives run 50% slower on my MBA M1 than on my iMac intel machine on the 3.1 gen. 2 ports. Thunderbolt drives are OK

FWIW, OWC has released a new TB/USB-C 4 0.8 meter cable

that they tout as lab tested and certified to work with all

flavors of TB and USB devices with USB-C interfaced.

It is priced significantly lower than the Apple TB3 cable:

https://eshop.macsales.com/item/OWC/CBLTB4C0.8M/

Contact OWC and let them know what is going on. Maybe there

is some drive firmware that is a problem with the new ports. They

are usually very, very helpful.

Hi

I fount the same concern with a new T7 drive.

Purchased a Thunderbolt 3 cable and connected and gained

Speed: Up to 10 Gb/s. Manufacturer: Samsung

worth in considering the cost of the drive :)

FWIW, it is an Intel chip that is the interface for the new

TB4/USB4 standards. If it is not a bug in the Intel chip itself,

then a solution via drivers may be possible.

Make you voices heard via Apple support directly since

you have warranty support and open a support ticket.

That is going to be the most effective means to draw attention

to the issue. Also, don't stop at "level 1" support and request

higher level support.