How to enable PCIE tunneling in Thunderbolt 4

[vignessh]

Hello,

I'm trying to get Thunderbolt working on my PC. The following is the configuration of my system.

Monitor: Apple Studio Display

CPU: Intel i5 13600K

Memory: GSkill DDR5-6800

Motherboard: Asus ROG Strix Z690-E Gaming WiFI

BIOS: 2703

GPU: Sapphire Nitro+ RX 7900XTX OC

PSU: Corsair RM1000

Thunderbolt card: Asus Thunderbolt EX 4

Thunderbolt driver: 1.41.1340.0

Thunderbolt card firmware: 36.0

Thunderbolt cable: Apple thunderbolt 4 cable

I've installed the thunderbolt add-on card in the lowest PCI slot as instructed in the manual, connected to the thunderbolt header in the motherboard, connected to the USB port in the motherboard and have attached a 6-pin power cable to the card as well. I have enabled Discrete Thunderbolt support in the BIOS, have installed the latest version of the drivers, however, I still see that the Thunderbolt Control Center app is showing that PCIE tunneling is Disabled.

What is working so far

- If I connect the thunderbolt out (first port) from the card to say my ipad pro, I can see the ipad is getting charged.

- If I connect the thunderbolt out (first port) from the card to my Macbook Pro, I can see the laptop is getting charged.

- If I wire up my GPU to the card using the supplied Display Port -> Mini display port cables and connect the first thunderbolt port from the card to my Apple Studio Display monitor, I can see the display. In the Thunderbolt control center, I can see the monitor listed under port 1, with the status as "Not Connected".  I believe because of this, only the display is working and the audio or the webcam in the monitor does not work.

Where I'm stuck

I believe I need to get the PCIE tunnelling enabled somehow in order to get the display, audio & webcam to work properly. I went through a whole bunch of posts and haven't been able to find a way out.

Please help.

[vignessh]

Hello @Jiaszzz_ROG,

Thanks for the immediate response.

I'm running a Sapphire Nitro+ RX7900XTX GPU and have installed it in the PCIE x16 (G5) lane, closest to CPU. I have installed the Asus Thunderbolt EX 4 add on card in the PCIE x 16 (G4) lane, the bottom most one. I'm using only one monitor - Apple Studio Display.

The Thunderbolt EX 4 add on card came with Display Port - mini Display port adapter cables and I'm using the same to connect the GPU to the Thunderbolt EX 4 card (GPU Display Port out -> Thunderbolt EX4 addon card mini display port in).

If I now take the Apple Thunderbolt 4 cable and connect the Studio Display monitor with the Thunderbolt EX4 add-on card, I can see the PC booting up, and Windows display is fine. However, the monitor in-built speakers and webcam are not recognized and hence won't work. Also, when I open the Thunderbolt Control Center app, I can see the monitor connected to Port 1, but it shows the thunderbolt connection status as "Not connected". I believe this is linked to the "PCIE tunneling disabled". 

Attached devicesPCIE tunneling shows disabled

[Jiaszzz_ROG]

Hello, @vignessh 

Based on previous experience, whether PCIe tunneling is enabled or not depends more on whether the device is recognized than on manually turning it on. 
Could you please refer to the steps explained in the relevant thread and try updating the NVM firmware of the Asus Thunderbolt EX 4? 
After that, please check again to see if the issue can be resolved.

Thank you.

[vignessh]

Hello @Jiaszzz_ROG ,

Thank you, I did try updating the NVM firmware and it says I'm already on the latest firmware with this message.

[Jiaszzz_ROG]

Hello, @vignessh 
May I ask if you have any specific specifications or model details for the Apple Studio Display?
To better understand your situation, please provide the following information:
- What is the current OS version and OS build that you are using?
- Can you confirm if your ThunderboltEX 4 is connected correctly as shown in the diagram?

- Which PCIeX16 slot is your ThunderboltEX 4 currently connected to?
If you try moving it to the PCIeX16 (Gen 3) slot, does it improve the situation?

- What are the related settings in the BIOS? Have you tried setting the PCIe slot where ThunderboltEX 4 is installed to Gen 3?
- Could you please try connecting a non-Apple product to test if it works?

Thank you.

[vignessh]

Hello @Jiaszzz_ROG ,

Thank you for the suggestions.

- May I ask if you have any specific specifications or model details for the Apple Studio Display?

The Studio Display is a 5K display panel with one thunderbolt 3 port for display input, audio & video and an integrated 3 port usb-c hub. Here are the tech specs for the same.

- What is the current OS version and OS build that you are using?

Edition Windows 11 Pro
Version 22H2
Installed on ‎23-‎03-‎2023
OS build 22621.2134
Experience Windows Feature Experience Pack 1000.22659.1000.0

- Can you confirm if your ThunderboltEX 4 is connected correctly as shown in the diagram?

Yes, I confirm the thunderbolt, usb headers and the 6 pin power are connected per the diagram.

- Which PCIeX16 slot is your ThunderboltEX 4 currently connected to?

The card is currently connected to the bottom most slot from the CPU - PCIEX16 (G4) in the diagram you have shared.

- If you try moving it to the PCIeX16 (Gen 3) slot, does it improve the situation?

Unfortunately, my GPU takes up 3 slots and thereby the Gen 3 slot is unusable for now.

- What are the related settings in the BIOS?

These are my current settings for Thunderbolt. Let me know if you need the info about any other settings.

- Have you tried setting the PCIe slot where ThunderboltEX 4 is installed to Gen 3?

Yes, I did try setting the PCIe slot to operate at Gen 3 via BIOS, but it doesn't seem to help.

- Could you please try connecting a non-Apple product to test if it works?

Unfortunately, I do not have any other devices with Thunderbolt support with me other than Apple products.

One more input:

I also got a Belkin VR charge & sync cable. This cable takes in Display port output from the GPU, takes in USB out from the back of the motherboard via USB 2.0 style slots and gives a USB-C output. Using this cable, I'm able to get the display, audio & video features of the monitor working as well at the native 5K resolution at 60Hz.

If I use the Thunderbolt EX4 card, I can get the display working at 5K resolution at 60Hz, but the integrated speakers, webcam, mic don't work.

Per the screenshot below, the Studio Display Speaker is the integrated monitor speaker. It is showing as working fine when I connect with the Belkin VR Charge & Sync cable. If I connect via the Thunderbolt EX4 card, this shows the status as not connected via USB.

Thank you.

[vignessh]

Hello @Jiaszzz_ROG ,

Thank you for the suggestions.

- May I ask if you have any specific specifications or model details for the Apple Studio Display?

The Apple Studio Display is a 5K panel with integrated speakers and webcam. It has one USB-C/Thunderbolt 3 input port that serves to carry the display, audio & video signals from the monitor to the attached device. It also has a USB hub where 3 other USB-C style ports are available for any other peripherals to be attached.

- What is the current OS version and OS build that you are using?

Edition Windows 11 Pro
Version 22H2
OS build 22621.2134

- Can you confirm if your ThunderboltEX 4 is connected correctly as shown in the diagram?

Yes, I can confirm the card is connected correctly as shown in the diagram (usb, thunderbolt headers connected to the motherboard and 6 pin power cable connected to the card from my PSU).

- Which PCIeX16 slot is your ThunderboltEX 4 currently connected to?

It is currently connected to the bottom most PCIe x 16 (G4) slot.

- If you try moving it to the PCIeX16 (Gen 3) slot, does it improve the situation?

Unfortunately, my GPU width takes up 3 slots and hence this PCIe x 16 (Gen 3) slot is not accessible for now.

- What are the related settings in the BIOS?

Please find the settings:
PCIE Tunneling over USB4: Enabled

Discrete Thunderbolt Support: Enabled

Wake up from Thunderbolt Devices: Enabled

DTBT GoSx Command: Enabled

Windows 10 Thunderbolt Support: Enable + RTD3

DTBT Controller 0: Enabled

TBT Host Router: Two port

- Have you tried setting the PCIe slot where ThunderboltEX 4 is installed to Gen 3?

Yes, I tried changing the setting in BIOS to Gen 3, but this did not help.

- Could you please try connecting a non-Apple product to test if it works?

Unfortunately, the only Thunderbolt / USB-C devices I have are all Apple products.

Thanks.

[vignessh]

Hello,

I tried an experiment today on this. Since I had my old RX580 GPU lying around still, I attempted to use that instead of the 7900XTX and moved the Thunderbolt EX4 card to the PCIEx16 (G3) slot (last but one slot from bottom). After booting up, I could see the PCIE tunneling was enabled in the Thunderbolt control center. 

Unfortunately, I cannot use this slot as I need to move back to my 7900XTX GPU. Just thought I'll post here for an update. If there is any way to make the bottom most PCIEx16 (G4) slot to work, that would be really appreciated.

Thanks,

[Jiaszzz_ROG]

Hello, @vignessh 

Thank you for providing the relevant information and assisting with cross-testing.
Based on your description, this issue may be due to the fact that the Thunderbolt EX 4 uses a PCIe 3.0 interface, which aligns with the PCIe x16 (G3) specs.

May I ask if you have updated the Intel ME to the corresponding version in the BIOS?
For example, the latest BIOS version of theROG STRIX Z690-E GAMING WIFI is 2703, which requires updating the Intel ME to 16.1.27.2176.

We have forwarded your relevant information and test results to the appropriate department for further investigation.
If there is any update, I will promptly reply to this thread and confirm with you.

We appreciate your patience in advance.

[vignessh]

Hello @Jiaszzz_ROG ,

Thank you for taking this up.

- May I ask if you have updated the Intel ME to the corresponding version in the BIOS?

Yes, I can confirm Intel ME has been updated to version 16.1.27.2176, and my BIOS version is 2703. 

I have also kept the PCIEx16 (G4) slot's setting to be Gen 3 per the BIOS, but it hasn't helped resolve the issue.

Will await updates from your end.

Thanks.