I have a Gemini 36 TB Thunderbolt 3 Dock and dual drive.
Using a Thunderbolt cable.

I have no Thunderbolt controller on
the PC to which I need to attach
this drive.
I've plugged the Thunderbolt cable
into a USB C -> USB adapter which
plugs into the PC fine, but the drive
is not seen. What am I doing wrong?
Thanks in advance to anyone who
can help.

root@hostname:/home/person# modprobe -v thunderbolt

insmod /lib/modules/4.4.0-210-generic/kernel/drivers/thunderbolt/thunderbolt.ko
modprobe: ERROR: could not insert 'thunderbolt': Function not implemented

That's on my Ubuntu 16.04 machine.
On my RHEL8 machine I get nothing.
Neither machine shows the drive.
Nothing of significance in dmesg.

On Thursday, November 9, 2023 at 10:22:51 AM UTC-5, David W. Hodgins wrote:
> On Wed, 08 Nov 2023 17:31:24 -0500, sgc2c <der...@gmail.com> wrote:
>
> > I have a Gemini 36 TB Thunderbolt 3 Dock and dual drive.
> > Using a Thunderbolt cable.
> >
> > I have no Thunderbolt controller on
> > the PC to which I need to attach
> > this drive.
> > I've plugged the Thunderbolt cable
> > into a USB C -> USB adapter which
> > plugs into the PC fine, but the drive
> > is not seen. What am I doing wrong?
> > Thanks in advance to anyone who
> > can help.
> Try running "modprobe -v thunderbolt", then check dmesg and syslog/journal for
> messages to see if it's detected then.
>
> Regards, Dave Hodgins

On 11/8/2023 5:31 PM, sgc2c wrote:
> I have a Gemini 36 TB Thunderbolt 3 Dock and dual drive.
> Using a Thunderbolt cable.
>
> I have no Thunderbolt controller on
> the PC to which I need to attach
> this drive.
> I've plugged the Thunderbolt cable
> into a USB C -> USB adapter which
> plugs into the PC fine, but the drive
> is not seen. What am I doing wrong?
> Thanks in advance to anyone who
> can help.
>

At a guess, the Thunderbolt 3 has four 10Gbit/sec lanes.
And, apparently, it is not interested in "variable rate"
like USB. To even think of trying this, we need interfaces
with "10" in the name, or a "multiple of 10".

With USB, I could attempt it with these:

USB-C USB3.2 2x2 (two 10Gbit/sec lanes) SS 20
USB3.2 (one 10Gbit/sec lane) SS 10 <=== my PC has this
USB-A USB3.2 (one 10Gbit/sec lane) SS 10 <=== my PC has this (red colored tab inside connector)

These might have labels such as "SS 10" or "SS 20",
where the 20 refers to two lanes of 10 each.
The connector on the USB-A might use a red plastic tab.
The red plastic tab one, is the only one worth trying,
in a USB-A connector.

Versus the blue or black plastic tab on the slower USB-A connectors
that aren't going to work.

The industry has been slow, to make plug-in PCI Express cards
for the job. Intel gates certification, and while some
motherboards on self-built PCs have "Thunderbolt Ready" headers,
that's merely the control path for a future add-on card. The
card was finished a couple years ago, but Intel was delaying
certification.

It is more likely, if your current PC only has blue USB-A connectors
on it, you need a plug-in hardware card with a red connector.

if you have a local computer store you trust, ask them.

Some brick and mortar stores allow 30 day returns.
This is not offered for some hardware types, so you have
to ask what the *current* policy is. Any time the good will
of a store is abused by customers, the returns policy can
change instantly. For example, the last hard drive I bought
was dead, and I took it back the next day for an exchange.

*******

You see the trick with these Thunderbolt Cards, in the picture. This is an Asrock
Thunderbolt 4 card.

https://c1.neweggimages.com/ProductImageCompressAll1280/15-548-008-V04.jpg

In small print it says:

2x5 "USB2 connectors to MB USB2.0 Header" OK, that's readily available

2x5 "TB1 connects to MB TB1 header" Uh, oh, what works here ??? control port (custom?)

1x5 "Factory Debug" No connection needed

Asus, Gigabyte, MSI make cards like this too, but who knows whether
TB1 control header is a standard ? Likely it is not a standard.
You would use a Gigabyte card on a Gigabyte mobo with TB1 connector.
You would use an Asrock card on an Asrock mobo having TB1 connector.

Whereas this is an example of a USB3.2 2x2 addin card. They should
have at least stamped "SS 20" on the faceplate. It would be normal
for cards like this to have an x4 PCI Express connector, and that
can plug into an x16 slot lower on the motherboard. (As you would not
want to remove the video card, just to use one of these cards.)
In my ten year old PC, the lowest slot is too slow for this card,
so transfer rate would be throttled a bit.

https://www.startech.com/en-ca/cards-adapters/pexusb321c

4 lanes PCI Express 5gbit/sec ==> 2 lanes USB3.2 10gbit/sec on USB-C
(This requires PCIe Rev2 min)
(PCIe Rev3 would be fine too)

Since the Thunderbolt could be similar to PCI Express itself,
expect 1, 2, or 4 lanes to work. That is why a USB-A at 10Gbit/sec
with adapter cable to USB-C, could be the minimum that works,
by connecting to 1 of the TB lanes.

Summary: At least get the candidate connector to "match on rate".

I don't know what is going to work, as I don't understand
anything faster than what is on my PC right now.

Paul

sgc2c <derf109@gmail.com> writes:

> I have a Gemini 36 TB Thunderbolt 3 Dock and dual drive.
> Using a Thunderbolt cable.

> I have no Thunderbolt controller on the PC to which I need to attach
> this drive.

With a quick look, the box has ethernet in the back. Maybe you can use
that instead?