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Level 2

208 points

What does USB 3.1 mean in System Information? Why am I not getting full speed on my SSD?

I have an M1 4 port 2021 Mac.

Trying to find out if there really is any difference between the Thunderbolt ports and the USB ports.

I have an OWC Envoy Pro USB-C drive and it's only a little faster on the Thunderbolt/USB-4 ports. The OWC site claims that AJA gives readings of 1002 MB/sec for write and 992 MB/sec for Read. I only get about 700 MB/sec. Latest reading (using AJA, as OWC does) is W: 787 R: 675 on the Thunderbolt/USB4 port.

And in the System Information report, what does USB 3.1 mean?

5 Gbit/s - USB 3.0 USB 3.1Gen 1 - ESB 3.2 Gen 1 - SuperSpeed USB

10 Gbit/s - USB 3.1 Gen 2 - USB 2.3 Gen 2 - SuperSpeed USB 10 Gpbs

It is almost beyond belief that the USB consortium (or standard board, or whatever) came up with their awful, confusing naming scheme. Just tell us if it's 5, 10, or 20. Sheesh.

Oh, I'm using an OWC Thunderbolt 4 cable. It's supposed to do all protocols, speeds, whatever, IIRC.

Oh^2: I'm using the Thunderbolt port on the Mac, and nothing comes up under Thunderbolt/USB4. The SSD comes up under USB under USB 3.1 Bus.

TIA!

iMac (M1, 2021)

Posted on Jul 23, 2023 11:31 AM

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betaneptune Author

Level 2

208 points

Jul 25, 2023 10:53 AM in response to HWTech

The information you provided is very useful. Thank you very much! But it doesn't answer the first question.

Which 3.1 is meant in the System Information USB panel? Gen 1, Gen 2 or either? Seems to me it should be more specific. I assume it's at least the 10 Gbps version, but maybe it means it could be Gen 1 or Gen 2.

BTW, I tested with a file of video footage, not an FCP library, e.g., which has a huge number of folders (as can be seen by clicking "Show Package Contents"), which "create" a large amount of overhead. I got at least that much right!!!

HWTech

Level 9

63,572 points

Jul 25, 2023 12:29 PM in response to betaneptune

betaneptune wrote:

Which 3.1 is meant in the System Information USB panel? Gen 1, Gen 2 or either? Seems to me it should be more specific. I assume it's at least the 10 Gbps version, but maybe it means it could be Gen 1 or Gen 2.

If they don't specify, assume the lowest option as it is usually the less expensive to manufacture. Plus OWC says the max speed is 1,006MB/s which is equivalent to 10Gbps max....does it really matter if it is 3.1 or 3.2, the speed rating is the same? The specification is so messed up all I recall is the speed differences, not the designations. Gen1 or Gen2 of either one is just doubling the transfer rates, I don't think it changes anything else.

The only thing I look for is the speed of the interface and making sure any USB3 device I get also supports the UASP protocol for the best transfer rates. Since this enclosure uses the ASMedia chipset, it probably supports UASP (I try to only get USB devices with that chipset as it has proven itself to me). Anything else is irrelevant to me. Besides, the updated markings are just going to show the USB symbol and the speed rating of the item so users will know what they are getting on the port.