Thunderbolt 4 Only Will Not Recognize eGPU

[ACAdkison]

The Omen laptop has a discrete 4080 GPU. But, due to heating and other issues under load, I prefer to use an eGPU.

The laptop is currently hooked to an Anker 778 TB4 hub and works flawlessly. The TB Control Center "sees" it and lists it as ANKER 778 12-in-1 Docking Station TB4. Every port and every device connected to the Anker hub works. At present, I am using it to send the video to my monitors via HDMI (1) and DisplayPort (1). 

However, I purchased a Sonnet Breakaway Box 850 T5 and after a week of troubleshooting with Sonnet, I returned it. The HP refuses to recognize it and Sonnet has no workaround for HP's configuration issues. The Thunderbolt Control Center doesn't even recognize a TB4 device attached. If I plug the Anker back in, it's picked up instantly.

I purchased a Peladin TB 4 eGPU setup and connected it to the laptop. THE EXACT SAME REACTION. The fans on the GPU spin up, but there is no activity on the laptop, it does not show up in Device Manager, and the Omen Gaming Hub Overlay will not allow switching, because it says there is no device. I've tried this with the discrete GPU enabled and disabled. The results are the same. The Thunderbolt Control Center doesn't "see" it either.

Note: both eGPU enclosures have additional ports (Ethernet, USB, etc.) None of them communicate with the laptop. It is as if the laptop recognizes the attached device, then immediately shuts down or blocks any signals to/from the device.

All BIOS and drivers are updated. The Windows Build is 26200. Nothing in the BIOS or Omen Gaming Hub allows access to anything Thunderbolt related.

Please advise.

[Kuroi_Kenshi]

Hi @ACAdkison,

Welcome to the HP Support Community!

Thanks for reaching out!

We're thrilled to have the opportunity to assist you and provide a solution.

I understand your HP OMEN laptop detects and works perfectly with a Thunderbolt 4 dock, but will not recognize any Thunderbolt eGPU enclosure at all, even though the enclosures power on. Let’s go through a few steps to check what could be causing this.

Confirm HP’s Thunderbolt eGPU support limitation
Many HP OMEN laptops do not support external GPUs, even with Thunderbolt 4 hardware.
HP restricts PCIe tunneling for eGPU use at the firmware level, while allowing docks and displays.

Understand why docks work but eGPUs do not
Thunderbolt docks mainly use USB, DisplayPort, and networking tunneling.
eGPUs require PCIe tunneling, which can be disabled independently by the system firmware.

Check Thunderbolt security level behavior
Open Thunderbolt Control Center when a dock is connected and note the security level.
On many HP systems, PCIe authorization for eGPU devices is blocked even though the port is TB4-certified.

Verify BIOS options are truly unavailable
Enter BIOS using Esc > F10 and check all menus.
On HP consumer and gaming systems, Thunderbolt PCIe / External GPU options are intentionally hidden and cannot be enabled.

Test with discrete GPU enabled (expected behavior)
HP OMEN systems with high-end discrete GPUs (like RTX 4080) often disable eGPU enumeration entirely.
Disabling the internal GPU in Windows does not change this because the block is in firmware.

Confirm Windows and drivers are not the cause
Since the Thunderbolt Control Center does not see the eGPU at all, this rules out Windows, NVIDIA, and driver issues.
Device Manager will not show anything if PCIe tunneling is blocked upstream.

Note the identical behavior across two eGPU enclosures
The fact that two different eGPU brands behave the same confirms this is not a Sonnet or Peladin issue.
This strongly points to HP platform restrictions rather than faulty hardware.

Understand Omen Gaming Hub limitations
Omen Gaming Hub can only switch GPUs if the system firmware exposes an external GPU device.
Since the firmware blocks enumeration, the app correctly reports “no device.”

Why Thunderbolt 4 certification is misleading here
Thunderbolt 4 certification does not guarantee eGPU support.
OEMs are allowed to restrict PCIe tunneling while still meeting TB4 dock and display requirements.

I hope this helps.

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