# Connecting a Multidock 10g to an iMac using TB2



## PeterBaumann (May 15, 2020)

Is there a dongle out there which has a USB-C slot and connects to the Thunderbolt 2 port on an iMac (Late 2014)? I've searched far and wide and can't seem to find one  

I've got a BlackMagic Multidock 10g arriving early next week, and am trying to find the best way to hook it up to an iMac with USB 3.0 ports or one of the Thunderbolt 2 ports on the back. USB 3.0 might have to be the solution for now but it's a bit of a shame to only be able to use half of the 10g's bandwidth.


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## Virtuoso (May 15, 2020)

Yes - one of these, available from most retailers (Best Buy/Amazon etc)









Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter


Effortlessly connect your Mac to a Thunderbolt 2 device with the Apple Thunderbolt 3 Adapter. Buy now at apple.com



www.apple.com





It has to be a Thunderbolt adapter as that is the protocol that the Multidock uses. Although it's the same physical connector as USB-C, a USB 3 adapter will not work at all. And it has to be bi-directional, unlike some cheaper ones that you might find on Amazon. Go with the official Apple one to avoid problems. Plug the adapter into your Multidock and use a TB2 cable to the iMac.

And yes, the price is horrendous! I had to buy two - one for my Multidock and one for a UA Apollo x8 interface.


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## PeterBaumann (May 15, 2020)

Wait, so is the Multidock USB C or Thunderbolt...? I thought it was USB-C for the 10Gs, so had assumed that TB3 would not play happy with it.

Appreciate for your thoughts.


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## Virtuoso (May 15, 2020)

Sorry - I misread your post. I have the older Multidock which is Thunderbolt only. Argh. Must get more sleep.


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## PeterBaumann (May 15, 2020)

No worries! The adapter you linked to does seem to refer to USB-C at multiple points so I'm a bit confused now as to whether it would work for the 10g or not.


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## jbuhler (May 15, 2020)

PeterBaumann said:


> Wait, so is the Multidock USB C or Thunderbolt...? I thought it was USB-C for the 10Gs, so had assumed that TB3 would not play happy with it.
> 
> Appreciate for your thoughts.


The new multidock is USB-C. As I understand it that dongle should work, as it passes both thunderbolt 3 and usb-c to thunderbolt 2. (USB-C and TB3 use the same connector.) Whether it will actually work with the Multidock, I'm not sure. When I inquired I got different answers and ultimately opted not to get it.


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## Virtuoso (May 15, 2020)

Apparently BlackMagic posted that it does work on their forum. But I also found this, which is very confusing...





__





Blackmagic Forum • View topic - Multidock 10g adapted to Thunderbolt 2?







forum.blackmagicdesign.com







> The Multidock 10G requries a Thunderbolt 3 connection for all of the supported functionality.



...suggesting that it is a Thunderbolt device, although all of the connectors have the USB logo and NOT the Thunderbolt logo.


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## PeterBaumann (May 15, 2020)

Is this right?
USB-C = 10g
TB2 = 20g
TB3 = 40g

Surely that BM forum response is incorrect then...? I can't see why they would limit a TB3 device to 1/4 of its potential speed. And as you say, the device images clearly say USB and not TB. To confuse matters further they've helpfully bundled the manual for the TB model and the 10g into one, so the specs get very muddled between the two! 

https://documents.blackmagicdesign.com/UserManuals/BlackmagicMultiDockManual.pdf?_v=1563778812000


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## Technostica (May 15, 2020)

USB-C is just the type of physical connector and can be used by TB, USB 3 and even USB 2.
The dock supports USB 3.1 Gen 2 which is 10Gbps.
USB is confusing as they change the names:
USB 3.0 = USB 3.1 Gen 1 = USB 3.2 Gen 1.


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## PeterBaumann (May 15, 2020)

I thought TB devices had the lightning graphic to show that they weren't USB(3.1)?


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## Technostica (May 15, 2020)

The dock supports dual 10Gbs Type-C connectors for a total of 20Gbs.
TB2 is also 20Gbs.
Ideally you'd want an adapter that converts TB2 to dual 10Gbs USB Type-C ports.
Then you can use the full bandwidth.
At least I think that's the implication but I may well be wrong as you may only get 10Gbs even using both connections.

I'll shut up as I don't know that much about TB2. 
Does it even support USB or did that only come with TB3?
I think the best you will get is USB 3.0 which is 5Gbps.
That's not a lot to share across 4 drives unless each of the 2 ports offers 5Gbs.


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## Virtuoso (May 15, 2020)

I think the adapter above will _probably_ work, but get one from somewhere with a returns policy just in case.


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## Technostica (May 15, 2020)

Virtuoso said:


> I think the adapter above will _probably_ work, but get one from somewhere with a returns policy just in case.


It appears to be TB to TB only and as TB2 seemingly doesn't support USB then it can't pass or receive a USB stream to a TB3 device.
So to get 20Gbs you'd need a TB dock.


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## PeterBaumann (May 15, 2020)

Technostica said:


> The dock supports dual 10Gbs Type-C connectors for a total of 20Gbs.
> TB2 is also 20Gbs.
> Ideally you'd want an adapter that converts TB2 to dual 10Gbs USB Type-C ports.
> Then you can use the full bandwidth.
> ...



I'm pretty sure you can't use both USB slots on the multidock to get 'double speed' on one computer. The second USB port is so 2 of the drives can be for a completely separate machine. 

ie. Single cable to computer for access to all 4 drives (10g speeds) or two cables to two computers for access to 2 drives each (10g speeds each)


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## Technostica (May 15, 2020)

PeterBaumann said:


> I'm pretty sure you can't use both USB slots on the multidock to get 'double speed' on one computer. The second USB port is so 2 of the drives can be for a completely separate machine.
> 
> ie. Single cable to computer for access to all 4 drives (10g speeds) or two cables to two computers for access to 2 drives each (10g speeds each)


It doesn't clarify a number of key issues.
I can't see a good reason why both ports can't connect to a single PC as they are just seen by the PC as external USB drives presumably?


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## Virtuoso (May 15, 2020)

To be honest, I'd try to get hold of the older Thunderbolt Multidock 2 if you can. It's 20Gb, plugs straight into a 2014 iMac (I've been using one myself for >5 years) and can be daisy chained with other Thunderbolt devices. The new one looks like it was made for USB-C computers and seems like a step backwards.


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## PeterBaumann (May 15, 2020)

Technostica said:


> It doesn't clarify a number of key issues.
> I can't see a good reason why both ports can't connect to a single PC as they are just seen by the PC as external USB drives presumably?


That is a good point. Not sure!


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## PeterBaumann (May 15, 2020)

Virtuoso said:


> To be honest, I'd try to get hold of the older Thunderbolt Multidock 2 if you can. It's 20Gb, plugs straight into a 2014 iMac (I've been using one myself for >5 years) and can be daisy chained with other Thunderbolt devices. The new one looks like it was made for USB-C computers and seems like a step backwards.



They seem to be very hard to get hold of, and for my purposes the TB2 speeds seemed overkill for SSD performance. USB-C has the advantage that I can use it dongle-free with my MacBook Pro & any USB-C ready iMac/MacPro I might get in a year or two. TB2 docks/cables are very expensive comparatively which is why I opted for the USB-C.


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## Technostica (May 15, 2020)

I think it's 10Gbps in total as if it was per port they'd surely make a noise about that!
So hopefully you can hook it up two of your USB 3.0 ports so at least each pair of drives share a 5Gbs port.


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