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Crosshair VIII Extreme Thunderbolt firmware update

Level 9

External USB4 drive won't work in 40GBps/PCI-E mode when connected TB4 ports on motherboard and falls back to 10GBps/UASP.
Intel JHL8540 on my motherboard has NVM version 28 (that's very old), and there is at least NVM version 36 for this controller.
I believe that is the reason of failure.
The drive works with 40GBps speed on other devces, like Macbook Air (2022) and Dell XPS 15 (2021).
Is there a way to update this firmware? I know that ASUS does provide updates for thunderbolt firmware on other motherboards.

I tried to contact support, they were of no help. case E23120048640-0001

Windows 11 22631.3078
Thunderbolt drivers 1.41.1379.0
JEYI TB2464 ASM2464PD firmware 231204850000


Customer Service Agent

Hello, @boorya 

After consulting with the relevant departments, we have confirmed that the value of Max Payload Size is related to the PCI Express transmission efficiency.
The MPS value is the result of automatic negotiation between the device and PCIE, and a larger MPS value does not necessarily indicate better performance.
The JHL8540 specification defines a corresponding payload value of 128 bytes, and we have determined that this is a specification limitation.

Thank you.

sharing complete hardware info & software config details will help us better understand the issue 🙂

Thank you so much for your help,
I hope that NVME36 version of thunderbolt controller firmware will eventually pass the QA and will become a part of a stable BIOS version for my motherboard (after all NVME36 is nothing new, and is already a part of release versions for so many ASUS motherboards).
Please pass my gratitide to the team behind motherboard firmware, it just feels so great to be heard 🤗

Level 9


I am facing the exact same problem described by boorya.

The extreme motherboard variant are always left behind when it comes to firmware updates.

Can you please ask the motherboard bios team to include this NVME36 TB4 firmware update in the next stable release of the BIOS ?

Thank you very much.



Level 9

Stable BIOS version 1505 updates thunderbolt NVM to latest 38 version, although it's not mentioned in changelog.
Custom version is no longer needed.


Level 9

This is great news !