TB Header / JTBT1 - MSI MAG Tomahawk

[aclarke_31]

Hi guys.

Having some trouble with an MSI MAG Tomahawk B760 WiFi DDR5 motherboard.

I want Thunderbolt and my motherboard has a TB Header on the base of the board.

The USBC on the back is just a USB C port but I really want a Thunderbolt port because of a piece of hardware I've just bought.

I'm looking for either a header I can connect direct to the board or a PCI Card I can connect.

Does anyone know what I need or where I can get help?

Thanks

[+Nik Louch Subscriber²]

msi.com/PC-Component/ThunderboltM4-8K

[aclarke_31]

Thanks Nik.

This card is kinda what I'm looking for.

Do you know if this connects to the motherboard via the TB Header / JTBT1 Header or if this is via the PCI Express slot?

I was wondering if there was just a cable I could purchase that would give me a TB connection, since the header is already on the mainboard.

Thanks

[Mindovermaster Global Moderator]

On 10/06/2025 at 12:13, aclarke_31 said:

Thanks Nik.

This card is kinda what I'm looking for.

Do you know if this connects to the motherboard via the TB Header / JTBT1 Header or if this is via the PCI Express slot?

I was wondering if there was just a cable I could purchase that would give me a TB connection, since the header is already on the mainboard.

Thanks

What Nik posted is your answer, bud.

[Jim K Global Moderator]

On 10/06/2025 at 12:13, aclarke_31 said:

Thanks Nik.

This card is kinda what I'm looking for.

Do you know if this connects to the motherboard via the TB Header / JTBT1 Header or if this is via the PCI Express slot?

I was wondering if there was just a cable I could purchase that would give me a TB connection, since the header is already on the mainboard.

Thanks

From my understanding....

Thunderbolt isn't like USB ... where you can simply plug a couple of ports into the header.  The header itself isn't "Thunderbolt" ... the header connects to the add-on Thunderbolt I/O card for management.

I'm sure Nik can better articulate...

 

On 10/06/2025 at 13:58, Mindovermaster said:

What Nik posted is your answer, bud.

...helpful as always...

[aclarke_31]

Awesome. That's what I was thinking Jim. Yea from what I can tell you connect the AIC card to the AIC header on the motherboard, so it doesn't just run through the PCI lanes. That's fine guys. Thanks for clarifying 🙂

I was getting a little bit lost with all of this, but I need a minimum of TB3 and the connector on the MB has it, but not on the back of my PC chassis / MB IO shield.

Anyway I found that the cheapest I can get it is Amazon at 70 quid, so I'm just gonna have to fork out for it. Thanks everyone. 🙂 👍 

Don't worry about Mindovermaster. He's just his chirpy cheerful self lol.

Thanks everyone 🙂

[+Nik Louch Subscriber²]

On 10/06/2025 at 20:24, Jim K said:

I'm sure Nik can better articulate...

You basically said all there is to say - so I can't really say much better

[aclarke_31]

Thanks Nik and thanks Mind.

Nik: Just on the off chance, you don't know where I could get this part at cheaper than normal price do you? I tried I few places but the I can find it at is 70GBP?

Just gonna have to suck it up and buy the add-on for my PC.

Thank you guys.

[+Nik Louch Subscriber²]

As it’s a niche part, and still a relevant one that serves just one purpose - I’d not expect to see 2nd hand items listed independently.

[Mindovermaster Global Moderator]

On 11/06/2025 at 01:27, Nik Louch said:

As it’s a niche part, and still a relevant one that serves just one purpose - I’d not expect to see 2nd hand items listed independently.

I see several on eBay. Am I blind, or is this something else?

Link

(I know this link isn't in UK, but an example)

[+Nik Louch Subscriber²]

On 11/06/2025 at 15:25, Mindovermaster said:

I see several on eBay. Am I blind, or is this something else?

Link

(I know this link isn't in UK, but an example)

User doesn't use dollars, and it's not much cheaper

[Mindovermaster Global Moderator]

On 11/06/2025 at 09:25, Mindovermaster said:

(I know this link isn't in UK, but an example)

 

On 11/06/2025 at 10:43, Nik Louch said:

User doesn't use dollars, and it's not much cheaper

You can't read? Price does not matter here. I was simply answering your false statement:

On 11/06/2025 at 01:27, Nik Louch said:

As it’s a niche part, and still a relevant one that serves just one purpose - I’d not expect to see 2nd hand items listed independently.

 

[+Nik Louch Subscriber²]

What’s with your crappy attitude again.

It isn’t much cheaper (a couple of £), it is a niche part, your link isn’t 2nd hard. Nothing I said is false so maybe you need to deal with your reading comprehension before accusing others.

You have a real attitude problem and seem to be against people trying to help. How you became a mod is beyond me because you seem to constantly display this crap attitude.

[goretsky Supervisor]

Hello,

The thing about Thunderbolt 2/3/4 PCIe cards is that in addition to the signals carried over the PCIe slot they are plugged into they need to send additional signals to the motherboard for which there is no standardized connection set of connections on the PCIe bus.  To get around this limitation, motherboard manufacturers can include a separate Thunderbolt header, which is often labeled as JTBT1 or TBT1 on the motherboard.  The Thunderbolt PCIe card has a corresponding header on it, and comes with a proprietary cable to connect between the card and motherboard.

While the additional signals that need to be sent over the Thunderbolt header are somewhat standardized, motherboard manufacturers are also free to implement whatever custom vendor-specific additions like like, like allowing a the system to recognize an on/off button on a Thunderbolt dock they alone offer to power up the system, or recognize what an external peripheral has been plugged in or unplugged from the Thunderbolt port. 

Features like this, plus the lack of requirements for standardized features, or even a standard physical layout for the Thunderbolt header, mean that manufacturers can implement what are Thunderbolt PCIe cards that are essentially proprietary in that all features only work with their motherboard and even then only when their custom cable is used between their motherboard and their Thunderbolt PCIe card.  There may be additional cables required in order to route a video card's signals through the Thunderbolt port as well.

Because of this, you need to go with the motherboard manufacturer's Thunderbolt PCIe card, unless you want to get a different brand, build a custom cable to connect it to your motherboard, and potentially give up features like hot-plugging devices to it.

I believe @Nik Louch identified a card which will work with your motherboard.  You can always double-check with the motherboard manufacturer just to be sure, or find out if there are any issues or limitations with that specific combination of motherboard and card.

If you purchase a used Thunderbolt PCIe card, make sure to check with the seller if it comes with all of the cabling necessary to use it, otherwise you may end up having to purchase that separately as well.

Regards,

Aryeh Goretsky
 

Edited June 12, 2025 by goretsky
edited for clarity

[aclarke_31]

Aryeh thank you ever so much. That's a perfect response.

Lots of information about this new Thunderbolt technology.

Thank you ever so much.

I have indeed ordered an MSI Thunderbolt M4 8K so it should go well with my MSI MAG B760.

Again thank you for such a detailed response.

Kind regards.

[Circaflex]

On 11/06/2025 at 09:46, Mindovermaster said:

 

You can't read? Price does not matter here. I was simply answering your false statement:

 

If youre going to delete my comment from this thread, calling out your poor attitude, you should also remove this comment.

[aclarke_31]

Well to finalise the thread, I bought the addin card as recommended but had teething problems trying to connect it to my eGPU.

After much research, I found that rated cabling is a thing and after connecting a rated thunderbolt 4 cable to the new USB addin card I started troubleshooting.

A few BIOS tweaks and updates here and there and everything is now connected and working. New eGPU is being picked up by Thunderbolt Control Center

Thank you to anyone that stopped and read the thread especially to the tech resources that stopped to post and help.

It was of massive help being able to reach out to the community as always. I just hope I haven't wasted too much of the community time trying to diagnose the problem.

Thanks for your help again. 😊

Kind regards

[Mindovermaster Global Moderator]

Alls well that ends well.