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OWC Express 1M2 / CalDigit TS4 data transfer speed

herbert7265

herbert7265

macrumors regular
Original poster
Jun 2, 2023
116
82
Mexico
Maybe I am missing something, but I have a question regarding the SSD data transfer speed on my CalDigit TS4 vs on my MacBook Pro M2.

A few days ago I purchased two OWC Express 1M2 enclosures and two WD Black SN850X 2TB SSDs, for external data storage and backups.

Using the SSDs connected directly to my MacBook Pro M2 I reach the stated transfer speeds of approx. 3,150 MB/s (OWC webpage). So far, so good.

But when I connect the SSDs via my CalDigit TS4 I reach only about 700 MB/s, even when I use the original cable of the enclosure and connect it to the TB ports of the TS4.

What do I miss in here? Something about different TB / USB / connection standards? Any clarification would be highly appreciated.

Herbert
 
If you look in System Information, does it show that the dock and your disks are connected as Thunderbolt/USB4 devices or USB? What speed does the connection speed show for all the devices?
 
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EDIT: Oops — I seem to have gotten this all wrong. Best advice is to skip reading this post!




I think I understand how this could happen.

The OWC Express 1M2 connects via the USB4 protocol, not a via Thunderbolt. It has a USB4 controller in it from ASMedia, not a Thunderbolt controller chip.

It will give full speed when connected to Thunderbolt ports that also support USB4. Not all do. Some are Thunderbolt 3 (all without USB4), some are Thunderbolt 4 without USB4, and some are Thunderbolt 4 with USB4. (Also Thunderbolt 5 with USB4.)

All M-series Macs support USB4 via their Thunderbolt (4 or 5) ports, but many (all?) Intel Macs do not. The CalDigit TS4 dock appears to be Thunderbolt 4 without supporting USB4. Thus, it would act like a Thunderbolt 3 port on an Intel Mac, and connect as USB 10 Gb/s, as the OWC page says:

Thunderbolt 3 port on Intel Mac or PCUSB (10Gb/s)990MB/s

I give OWC credit for making it clear the low performance to be expected for Thunderbolt 3 ports on PC or Mac, but it's unfortunate that they didn't mention that "Thunderbolt 4" does not always include support for "USB4". OWC may have overlooked the issue because, I think, all Macs advertised with Thunderbolt 4 ports do happen to support USB4. But manufacturers of other Thunderbolt 4 equipment made their own decisions.
 
Last edited:
Brian33 said:
I think I understand how this could happen.

The OWC Express 1M2 connects via the USB4 protocol, not a via Thunderbolt. It has a USB4 controller in it from ASMedia, not a Thunderbolt controller chip.

It will give full speed when connected to Thunderbolt ports that also support USB4. Not all do. Some are Thunderbolt 3 (all without USB4), some are Thunderbolt 4 without USB4, and some are Thunderbolt 4 with USB4. (Also Thunderbolt 5 with USB4.)
Click to expand...

Note Thunderbolt 4 should always include USB4 as Thunderbolt 4 is USB4 certified to Intel's standards with USB4 optional extensions made mandatory. There could be negotiation problems between different vendors' implementations but then I'd say one of the devices is non-conforming.
 
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@herbert7265 "But when I connect the SSDs via my CalDigit TS4 I reach only about 700 MB/s..."

Edit: I see you are using the correct ports. For some reason your enclosures aren't registering as USB4.
Since the OWC (@OWC_TAL )have said that the Express 1M2 enclosures don't support TB3, they are not registering correctly through the dock.

I think you need to check this with OWC?

Original reply:
The only two ports that are available for high speed transfer are the two ports on the back with the TB symbol.
Any other USB-C ports will give you the speed you are getting (USB 3.2 gen 2).

Actually you may find when you connect USB4 enclosures to the proper TB(4) ports, System Settings may show you are connecting using the TB 3 protocol (not USB4), which will a) run at about 2800MB/s R/W, and b) the USB4 enclosures may run a little cooler.
 
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First of all, thank you very much to all of you for your feedback and ideas.

No, I have still not understood fully or found the solution, but based on the advice I made some observations.

Here two screen shots of the system report:

1754612093809.png

1754612107306.png


As of my understanding, please correct me if I am wrong:
- the first screenshot shows correctly that as well the TS4 as the new fast SSD is connected to the TB ports of the MacBook
- the second screenshot shows as well the TS4 as two SSD, one of them my second new fast one, connected to an USB 3.1 Bus (of the MacBook?) as an USB3.0 Hub (of the TS4?).

As of my interpretation: While the TS4 seems to provide an USB3.2 Gen2 HUB, that would be sufficient for the fast SSD, this will not work as the TS4 is connected to an USB 3.1 Bus as an USB3.0 Hub, both "slower" connection standards.

My question now: Can this be resolved? And if yes, how?

Herbert
 
herbert7265 said:
First of all, thank you very much to all of you for your feedback and ideas.

No, I have still not understood fully or found the solution, but based on the advice I made some observations.

Here two screen shots of the system report:

View attachment 2535501
View attachment 2535502

As of my understanding, please correct me if I am wrong:
- the first screenshot shows correctly that as well the TS4 as the new fast SSD is connected to the TB ports of the MacBook
- the second screenshot shows as well the TS4 as two SSD, one of them my second new fast one, connected to an USB 3.1 Bus (of the MacBook?) as an USB3.0 Hub (of the TS4?).
Click to expand...

This is a little hard to follow -- would be easier if you associated each System Information/report with the specific physicial connections at the time of the report. For example one set of snapshots when Express 1M2 -> TB4 port on rear of TS4, TS4 upstream port -> MacBook Pro USB4 port and another set of snapshots when Express 1M2 -> MacBook Pro USB4 port.


herbert7265 said:
As of my interpretation: While the TS4 seems to provide an USB3.2 Gen2 HUB, that would be sufficient for the fast SSD,
Click to expand...

USB 3.x is limited to 10Gbps (ignore the 20Gbps extensions). As long as the Mac sees the Express 1M2 as a USB 3.x device, you will be limited < 1 Gbyte/second throughput to it.

herbert7265 said:
this will not work as the TS4 is connected to an USB 3.1 Bus as an USB3.0 Hub, both "slower" connection standards.

My question now: Can this be resolved? And if yes, how?
Click to expand...

To get ~ full performance of the Express 1M2 to the Mac, you need the Mac to see the TS4 as a Thunderbolt/USB4 device/hub and the Express 1M2 as a Thunderbolt/USB4 drive on the other side of that hub.

One issue I just noticed: the MacBook Pro M2 only supported Thunderbolt 3/USB4. Not sure how the TS4 interacts with that. I would think the TS4 would see it as a USB4 hub (without TB4 extensions) and then see the Express 1M2 as a USB4 drive (the standard to which the drive was designed anyway). However, we've already seen that the Express 1M2 doesn't work with Intel Macs at Thunderbolt 3 and drops down to USB3 speeds there for reasons not entirely clear to me. Though not exactly the same thing something similar could be happening here.
 
If I'm reading this correctly, one of the SSD's is connecting fast (at USB4) speed and one is not (USB3)? Are both in the same serial number range (or close by)? There might be a firmware update for the enclosure that could address the linking speed- I've seen it a handful of times. Less than a fraction of a percent compared to all units shipped, but still see it on occasion.
 
OWC_TAL said:
If I'm reading this correctly, one of the SSD's is connecting fast (at USB4) speed and one is not (USB3)? Are both in the same serial number range (or close by)? There might be a firmware update for the enclosure that could address the linking speed- I've seen it a handful of times. Less than a fraction of a percent compared to all units shipped, but still see it on occasion.
Click to expand...
Hello
Thank you very much for your feedback.
Yes, both enclosures are in the same serial number range (3142059023 and 3142059026).
No, both SSD´s show the same fast speed when connected to the computer and the same slower speed when connected to the TS4 dock.
But, where could I get the most actual firmware for these enclosures?
Herbert
 
@bzgnyc2

Hello
Thank you very much for your feedback.

bzgnyc2 said:
One issue I just noticed: the MacBook Pro M2 only supported Thunderbolt 3/USB4.
Click to expand...
I am not sure what to do with this information.
When I look into the technical specifications of my computer (MacBook Pro M2 Max, 16-inch 2023, Model Identifier: Mac14,6) it states this:

1754703025372.png


bzgnyc2 said:
To get ~ full performance of the Express 1M2 to the Mac, you need the Mac to see the TS4 as a Thunderbolt/USB4 device/hub and the Express 1M2 as a Thunderbolt/USB4 drive on the other side of that hub.
Click to expand...
Yes, that seems to be the / an issue, as
- the screenshots show that the TS4 is recognized as a TB device
- also the SSD connected directly to the computer is recognized as an TB device
- while the SSD connected to the TS4 (to one the TB ports of the TS4!) is only recognized as an USD device.

Herbert
 
@OWC_TAL

Doing some more analysis to understand this topic better I think everything comes down to this question:

Why is the 1M2 recognized as a TB device when connected directly to a TB port of the computer but recognized as a USB device when connected to a TB port of the TS4?

Please see here:

1M2 connected (with its original cable) directly to my MacBook Pro M2 Max!

1754840391442.png


1M2 connected (with its original cable) to a TB port of the TS4! NOT recognized as a TB device on the TS4, but as a USB device!

1754840572571.png

1754840722547.png


Herbert
 
herbert7265 said:
@bzgnyc2

Hello
Thank you very much for your feedback.


I am not sure what to do with this information.
When I look into the technical specifications of my computer (MacBook Pro M2 Max, 16-inch 2023, Model Identifier: Mac14,6) it states this:

View attachment 2535803
Click to expand...

I looked up the specs for a MacBook Pro M2 (what you provided initially):

MacBook Pro (13-inch, M2, 2022) - Technical Specifications - Apple Support

support.apple.com support.apple.com

However if you have one of the 14" or 16" 2023 MacBook Pro M2 models then yes you should have TB4 so we can nix that as a potential cause.
 
herbert7265 said:
@BrianBaughn



Hello Brian
Let me see if I can do it in a timely manner.
On the other side, I already contacted the support of OWC and CalDigit and will see what they can tell me.
Herbert
Click to expand...

That makes sense at this point and I would see what Caldigit has to say. This is a pretty mainstream configuration and it's pretty clear your USB4 drive is getting dropped to USB3 when connected through the hub despite all the standards. They should be able to duplicate your configuration relatively easily.
 
Hi Herbert,
You have excellent advice and I hope Cal Digit resolve your problem.

For what it may be worth I wish to comment, as I have been similarly frustrated by these TB4 and USB 4 issues and can sympathise with you. You have bought top quality TB4 external gear and are receiving TB3 speeds at best.

The major factor seems to be the need for all external hubs to encrypt data for security. Encryption slows the data transfer process to at least half speed of the external chip capacity. You may know that already.

Further the appalling inconsistent/misleading advertising of USB/TB and their implementation by Apple and other manufacturers makes the task of achieving best results very difficult. We have to be detectives in order to ensure compatibility. This article is interesting:

https://www.reddit.com/r/buildapc/comments/11l9qq0/why_your_external_ssd_is_not_hitting_max_speed
Being three years old it has been updated so scroll down to updated 2024/2025 section.

Also Howard Oakley wrote of his experience testing M1 Macs: https://eclecticlight.co/2022/04/22/what-performance-to-expect-from-ssds/

These articles will not answer the specific Cal Digit question but do offer insights which I found useful. You may too.

I look forward to reading your post after Cal Digit reply.

Good Luck.
 
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