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

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Level 1

45 points

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

I recently replaced my 2018 i7 Mini with a new M1 model. One peripheral I had attached to my "old" Mini was a 2-bay USB 3.1 Gen 2 enclosure with two SSDs in it, striped for speed. (Redundancy isn't an issue for its function.) Like on the i7, the enclosure is directly attached to the M1 Mini.

After Blackmagic released their new version of the disk speed test, I did my usual benchmarks of my drives to see how they perform. I was surprised to see the enclosure report back about half the speed it usually does (around 400MB/s as opposed to 850-900MB/s.) Fearing some sort of issue, I ejected it and connected it to the late 2019 16" i9 MacBook Pro I use for work. Just as on the Mini, it's directly connected. On that machine, it ran as expected. A bit more looking with the System Profiler shows that on the M1 Mini, the link speed to the enclosure is 5Mbps, while it shows up at the full 10Mbps on the MacBook Pro.

After doing some searching around, I see that others have seen this issue with the new "USB 4" equipped M1 Macs. (I use the quotes because the USB specs are a nightmare these days.) However, as murky as things seem, from what I can read the ports on the M1 Mini should support USB 3.1 Gen 2 at the full 10Gbps speed.

Am I missing something? Losing that much speed on a 2T external drive really hurts. Is this a bug, or the result of some confusing statements by Apple?

Mac mini, macOS 11.0

Posted on Nov 30, 2020 3:13 PM

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Answer 1

Top-ranking reply

johngwheeler

Level 1

14 points

Dec 9, 2020 11:45 PM in response to Peter Wargo

I have the same issue with a 1TB SATA3 SSD in a USB 3.1Gen2 enclosure.

It connects at 10Gbps on my MBP16 and at only 5Gbps on my M1 Mini.

read speed drops from 525MB/s to 380MB/s - quite a significant downgrade!

Same performance on the USB-A and TB3 ports

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Answer 2

Peter Wargo Author

Level 1

45 points

Dec 28, 2020 4:27 PM in response to MyApple8MyPC

I would hope it was obvious from the above postings that I'm using the correct ports. Especially if you read the troubleshooting steps.

I honestly wish folks would take the time to read the postings carefully before offering what amounts to a non-answer.

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Answer 3

Nov 30, 2020 4:59 PM in response to Peter Wargo

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.

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Answer 4

RayAdams

Level 1

4 points

Jan 9, 2021 3:52 PM in response to Peter Wargo

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

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Answer 5

DonH49

Level 6

16,710 points

Feb 6, 2021 3:21 PM in response to Peter Wargo

I'm no expert but maybe that enclosure does connect at 5 instead of 10 and would connect at 10 if the connector was thunderbolt and not usb-c. "2-bay USB 3.1 Gen 2 enclosure with two SSDs"

maybe this would be a huge difference between TB4 on an m1 Mac vs TB3 on an intel Mac.

read this article, very interesting. https://eshop.macsales.com/blog/68484-thunderbolt-on-the-m1-mac-mini/

I 'm thinking if this was attached , you would get those rated speeds. https://eshop.macsales.com/shop/owc-thunderbolt-hub

Here's the pict of that TB4 dock:

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Answer 6

Peter Wargo Author

Level 1

45 points

Nov 30, 2020 5:12 PM in response to Malcolm J. Rayfield

Thanks for asking. It's the TB/USB-C ports, as that's the only way you can connect it. I mentioned that I was directly connecting to both the Mini and the MacBook Pro, and only USB-C connections can do 10Mbps.

Cheers,

-Pete

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Answer 7

Peter Wargo Author

Level 1

45 points

Nov 30, 2020 8:45 PM in response to trevoz

That may be due to something that Samsung controller is doing right (or differently) than some others. I saw some mention of that in this thread: https://forums.macrumors.com/threads/usb-on-m1-macs-isnt-actually-10gb-s-also-definitely-not-usb4.2269777/ on MacRumors. Some seem to have good luck, others don't. In my case, I'm using a case with an ASMedia ASM1352R-Fast controller. It's played nice with the Intel Macs, I really suspect there's something going on with USB 4 and how it's implemented.

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Answer 8

Peter Wargo Author

Level 1

45 points

Dec 13, 2020 1:22 PM in response to woodmeister50

No. It's a laptop I use for work, so I can't update it until some mission-critical packages are compatible.

HOWEVER

Before I replaced my 2018 i7 Mini with the M1-based 2020, I was using that external enclosure under Big Sur with no issues. It performed as it should, so I suspect the OS is not the issue.

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Answer 9

Dec 28, 2020 1:23 PM in response to Peter Wargo

I'm having the same issue with an external enclosure that uses the ASM1352R-Fast, but my issue is in the Early 2020 Intel Macbook Air. The same enclosure works at 10Gbps connected to a 2019 Mac Pro

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Answer 10

Dec 28, 2020 1:38 PM in response to Peter Wargo

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.

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Answer 11

Peter Wargo Author

Level 1

45 points

Dec 29, 2020 3:15 PM in response to woodmeister50

Inateck FE2101. ASM1352R-Fast chipset.

What irks is that it works so well on any previous Mac (2018 Mini and 2019 16" MBP) at 10Gbps, only the M1 drops to 5Gbps. As I've said before, one would think this wouldn't happen.

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Answer 12

IgorKuc

Level 1

4 points

Jan 2, 2021 7:33 AM in response to Malcolm J. Rayfield

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 ?

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Answer 13

Jan 2, 2021 9:10 AM in response to IgorKuc

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.

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Answer 14

trevoz

Level 4

1,990 points

Jan 9, 2021 5:26 PM in response to RayAdams

> 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

My T7 (currently in Samsung's hands for replacement due to the same low write speed) was still getting 900+ on my M1 Mac mini, so I think this is your T7's failure and not attributable to the M1. Unfortunately, if you check the net, you'll find this is a common problem with the T7 :(

In any event, you are conflating two issues here - this thread was about the link speed of various disk enclosures dropping from 10Gbps to 5Gbps (which is not your issue).

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Answer 15

Jan 10, 2021 4:34 AM in response to Peter Wargo

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.

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

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