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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


firmware updte did work 😍 now the drive connectes natively



the speed is lower than direct connection to m.2 slot on motherboard,
that is expected as JHL8540 thunderbolt controller is limited to pci-e 3.0 x4 connection.

just for comparison with previous hwinfo screenshot:

Screenshot 2024-01-22 092656.png


where did you get the firmware update from?

AMD Ryzen 9 7950X3D | ROG Crosshair X670E Extreme [1905] | Sapphire Nitro+ Radeon RX 7900 XTX Vapor-X | G.Skill F5-6000J3040G32GX2-TZ5NR | 2TB Samsung 990 PRO | 2TB Samsung 980 PRO | 2TB Samsung 970 EVO Plus | Samsung Odyssey Neo G9 | ROG RYUJIN III 360 ARGB | ROG Thor 1200P | ROG Chakram X | ROG Strix Flare II | ROG Theta 7.1 | ROG Cetra True Wireless | ROG Balteus Qi | ROG Carnyx | ROG Eye S | ROG Aura Terminal | ROG Throne | ROG Spotlight | ROG Strix Arion | Windows 11 Pro

Could you please send me the custom bios in order to fix my thunderbolt 4 problem

Customer Service Agent

Hello, @m1n3fr3ak3 

May I inquire about the model of the motherboard you are currently using and what specific issues you are experiencing?

If the model or issue differs, to avoid confusion, we suggest you start a new discussion thread and provide detailed hardware specifications, software versions, and a description of the scenario.

Thank you.

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

Its the asus rog crosshair viii extreme x570,

for me thunderbolt works but i would have to start my thunderbolt device first then turn on my computer and if i happen to turn off my device while my pc is on it wont connect back

Level 7

This is the exact same issue I'm having with the Asus ProArt X570-Creator (same JHL8540 TB4 Controller as ROG CROSSHAIR VIII) and a MAIWO USB4 NVMe enclosure which uses the ASM2464PD chipset but Asus email support is completly useless so far and saying they don't have any updates available even though the ThunderboltEX 4 AIC uses the same chipset and already received the 36.0 NVM firmware update.

UPDATE: After enough asking, support finally got up the chain high enough that they sent me a custom BIOS with NVM 36 which resolved the issue.


Level 9

enabling thunderbolt in BIOS reduces pci-e payload size to 128 bytes, the maximum size that JHL8540 supports per specification.
this leads to performance loss for all device that are connected to pci-e via x570 chipset.
Is this normal behavior?

with Thunderbolt:

2024-01-31 (9).png


2024-01-31 (10).png 

Thunderbolt disabled:

2024-01-31 (11).png

2024-01-31 (12).png

There are multiple threads online about amd chipsets limiting pci-e payload size to a "weekest link" - a device with smallest payload size support. Is it still the case?