Interesting article: M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

[danqi]

I just came across this article from yesterday, which is making my search for an external HDD and SDD enclosure even more complicated. I was just about to order a Sabrent 4-bay enclosure (+ SSD brackets), but now I am not so sure. I don't really need Thunderbolt for my SATA HDDs and SDDs but I would like USB 3.1 Gen 2 speeds...

M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2

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.

eclecticlight.co

 

[atonaldenim]

Check this thread for many more details: https://forums.macrumors.com/thread...ally-10gb-s-also-definitely-not-usb4.2269777/

Eclectic Light Co. is a great resource, I think he misstated the issue slightly. With the Samsung T5 people are saying that it reports itself as a 5Gb/s device in System Information. It's a SATA SSD so a 5Gb/s connection wouldn't really be a big problem on that particular SSD, but they are mad that it doesn't report itself as a 10Gb/s connection which it does on an Intel Mac. Many other devices do show up as 10Gb/s connections in System Information, just not the Samsung T5.

M1 Macs and certainly the Studio do support 10Gb/s USB connections, but there is a little bit more uncertainty compared to Intel Macs of how they will perform. There is generally about a 20% speed decrease on USB 3 drives compared to Intel Macs. It's kind of reminiscent of how early USB 3.0 controllers tended to get about 300MB/s speeds, but as USB 3.0 technology matured, later USB 3.0 controllers were able to get up to about 500MB/s. Apple's new Thunderbolt/USB controllers in the M1 chips are in the "early" phase of being less mature technology, while Intel's Thunderbolt/USB controllers are definitely more mature and faster.

If you hook up the USB-C device to a downstream Thunderbolt port on a Thunderbolt dock or monitor, that is a way people have found to speed up devices that are getting particularly slow speeds on M1. I haven't tried that yet.

Here's some initial testing I've done with my Sandisk Extreme 2TB SSD V2 (USB-C 10Gbps). The write speeds are pretty close, but the read speeds are a bit worse on the Mac Studio Ultra. It's a little disappointing but it's livable. I'd guess that with HDDs it wouldn't be a huge issue, but I'll probably do some more testing with my Ultra in the near future.

 

[danqi]

Thanks! That whole mess is quite complex....

I plan on getting myself a 4-bay USB 3.1 gen 2 enclosure. I think I will just try to test if there is a difference between connecting it directly to a Thunderbolt port on the Mac Studio and connecting it to the Studio Display.

On a sidenote: Can the Blackmagic speed test access multiple drives at the same time that are not in a RAID? Because the enclosure will be filled with SATA drives and will only be able to max out the connection when multiple drives in it are tested at the same time....

 

[atonaldenim]

You could temporarily put them into a RAID0 array with AppleRAID just for the purposes of speed testing.

Otherwise I don't think you can run multiple instances of Blackmagic Disk Speed Test at the same time, but you could run Blackmagic on one drive, AJA System Test Lite on another drive, AmorphousDiskMark on another one, Stibium from Eclectic Light Co. on another one... just note each app will give you slightly different numbers, so you can't compare them to each other.

You could also use the great program CopyQueue and simultaneously do a large file copy to/from each drive, and turn on CopyQueue's speed readout to see how each drive is performing.

 

[danqi]

You could temporarily put them into a RAID0 array with AppleRAID just for the purposes of speed testing.

Otherwise I don't think you can run multiple instances of Blackmagic Disk Speed Test at the same time, but you could run Blackmagic on one drive, AJA System Test Lite on another drive, AmorphousDiskMark on another one, Stibium from Eclectic Light Co. on another one... just note each app will give you slightly different numbers, so you can't compare them to each other.

You could also use the great program CopyQueue and simultaneously do a large file copy to/from each drive, and turn on CopyQueue's speed readout to see how each drive is performing.

Thanks, those are some great ideas!

 

[QuietOC]

...It's kind of reminiscent of how early USB 3.0 controllers tended to get about 300MB/s speeds, but as USB 3.0 technology matured, later USB 3.0 controllers were able to get up to about 500MB/s. Apple's new Thunderbolt/USB controllers in the M1 chips are in the "early" phase of being less mature technology, while Intel's Thunderbolt/USB controllers are definitely more mature and faster.

It was a storage protocol change that sped up USB 3 drives:

USB Mass Storage Bulk Only Transfer (BOT) -- slow
USB Attached SCSI (UASP) -- faster

It sounds like Apple sometimes doesn't enable UASP: https://arstechnica.com/civis/viewtopic.php?t=1478442