Thunderbolt 5 in New Macs: Features, Benefits, and Is It Needed?

[Melbourne Park]

About Thunderbolt (while this is really off the topic it is perhaps related to the topic) I was going to sell my PCI RAID card because it would likely run at around 3,000 MB/s and I thought a T-5 would be faster. But I suspect to achieve such speeds may take producers more time. There are very few Thunderbolt 5 products being sold, despite some reviews on different products which reveal great Blackmagic speeds which however seem to benefit from an external drive's cache rather than large file transfer speeds.

So I did a search on using the NVME drives inside the RAID card (I can just buy an external T-3 PCI box). The first one I found was this one on Amazon, but a maker who is going to sell a Thunderbolt 5 external drive (but its not available yet). The case is this one:

SABRENT Thunderbolt™ 3 Certified M.2 NVMe SSD Tool-Free Solid Aluminum Enclosure (EC-T3NS)​

I read the description they says (including they are one of the few fully Intel certified for Thunderbolt) but in the last paragraph:

• PLEASE NOTE: NOT compatible with USB-C ports. Your device must have a compatible Thunderbolt 3 port, otherwise the enclosure will not work!

My question: I had thought an external Thunderbolt enclosure would just be slower when attached to any USB-C port? My MacPro 5,1 does have a USB Type-C card in it, but its not Thunderbolt. Although I doubt I be using the MacPro 5,1 any more.

There certainly seems to be a lot of variations between "compatible with Thunderbolt" and actually providing Thunderbolt 3 data performance speeds in these products. One even said do not use Western Digital 750s, which is what my RAID card has, and it said while read speeds could hit 2,200 write speeds topped out at 1,400.

 

[constructor]

SABRENT Thunderbolt™ 3 Certified M.2 NVMe SSD Tool-Free Solid Aluminum Enclosure (EC-T3NS)
I read the description they says (including they are one of the few fully Intel certified for Thunderbolt) but in the last paragraph:

• PLEASE NOTE: NOT compatible with USB-C ports. Your device must have a compatible Thunderbolt 3 port, otherwise the enclosure will not work!

My question: I had thought an external Thunderbolt enclosure would just be slower when attached to any USB-C port? My MacPro 5,1 does have a USB Type-C card in it, but its not Thunderbolt. Although I doubt I be using the MacPro 5,1 any more.

When the device has a Thunderbolt 3 controller it uses the physical USB-C port but it "speaks" only the Thunderbolt protocol, not the USB protocol – those are distinct and separate! So the port must be Thunderbolt-certified to work with that device (at least Thunderbolt 3 or newer, or potentially also Thunderbolt 1/2 with an adapter if the device can support the slower speed).

Reason is that Thunderbolt will tunnel the same actual PCIe protocol which would be used for an internal SSD module in a PC or Mac Pro and the external Thunderbolt drive will then actually appear as a PCIe device to the Mac (you can see that in System Information).

One positive upshot of this is that via PCIe the Mac can use the Trim commands of the drive to release unused SSD sectors so the SSD can clear those sectors and ready them for quicker re-use which helps both performance and longevity of the SSD.

If the port only "speaks" the old USB drive protocol that protocol cannot talk to a PCIe drive so it would not work with a Thunderbolt device. Also the USB protocol blocks the drive's Trim commands so a USB-only SSD will be slower and wear out faster.

This situation can change with USB4, however: USB4 has a similar PCIe tunneling feature as Thunderbolt does, so a fully featured USB4 port can be able to talk to a USB4/Thunderbolt device (which can talk PCIe even through the USB4 protocol) even if that port is not explicitly certified for Thunderbolt, and should also be able to talk to Thunderbolt-only devices.

There certainly seems to be a lot of variations between "compatible with Thunderbolt" and actually providing Thunderbolt 3 data performance speeds in these products.

That should refer to USB4 ports as described above!

 

[joevt]

My question: I had thought an external Thunderbolt enclosure would just be slower when attached to any USB-C port? My MacPro 5,1 does have a USB Type-C card in it, but its not Thunderbolt. Although I doubt I be using the MacPro 5,1 any more.

Some Thunderbolt 3/4 or USB4 enclosures have a separate USB to NVMe bridge chip that can be used when the enclosure is not connected to a Thunderbolt host.
https://www.acasis.com/products/aca...nderbolt-3-4-usb3-2-3-1-3-0-2-0-type-c-tbu405

If the enclosure does not have such a bridge chip, then it cannot be used with your Mac that does not support Thunderbolt.

 

[Melbourne Park]

OK I now get it.

I had wondered with various T-3 PCIe boxes, some of which have ethernet and USB ports as well - whether all would work. If the M Mac sees the box as PCIe (and I knew that is how they are recognised and I guess thank you Mac Pro) then those other ports would work. It might pay to

Some Thunderbolt 3/4 or USB4 enclosures have a separate USB to NVMe bridge chip that can be used when the enclosure is not connected to a Thunderbolt host.
https://www.acasis.com/products/aca...nderbolt-3-4-usb3-2-3-1-3-0-2-0-type-c-tbu405

If the enclosure does not have such a bridge chip, then it cannot be used with your Mac that does not support Thunderbolt.

OK. Of course the place to put a PCIe RAID card is in the PCIe slot of the 5,1!! The only good purpose for the 5,1 now is CS6 photoshop and storage. And really it has no purpose but it's sort of part of me. Or like a very faithful dog that's only been let down by the various kennel club software members who won't play with him anymore.