USB4 Root Router USB4 Host Router Handshake problems

Question

USB4 Root Router USB4 Host Router Handshake problems

Glen Titanic 0

I have spent many hours trying to fix this problem. I have an MSI Aregis RS2 Ultra7 265K desktop. This has a Dedicated USB4 Thunderbolt type C port on back panel. The problem is high speed memory card and readers that ask for 40gps speed somehow do not handshake properly and windows drivers force the read write speeds down to USB 2.0 speeds, making this thunderbolt port useless. It also takes a minute or so to register with the computer before assigning a drive letter to my 40gps reader, which it does, but becomes extremely unstable causing crashes. My current periferal I am connecting to my USB4 Thunderbolt port is a Pergear CF Express type B 4.0 40gbs reader with a Pergear CF Express Type B 4.0 512gb memory card. I am using the certified proper usb4 high speed cables that came with the unit as well as other proper 240w 40gps cables. I have arranged a second support ticket to MSI whom have yet to respond again. I have contacted the Pergear mfr as well, but I have already tried others like OWC Atlas and Sabrent which I returned thinking it may be there fault . But according to AI and many hours of adjusting windows and windows bios settings and motherboard settings it all boils down to the drivers of windows USB4 Root Router and USB4 firmware handshake problems causing the bottlenecks of speed and device handshake for high speed memory cards and readers. This is a well documented problem with this particular Intel motherboard which is a Pro Z890-S wifi Ps (MS-7E58) vers 1.0 motherboard. But I believe it is the Microsoft drivers that wholely run the USB4 Architecture and not the mother board manufacturer. I am sure I am not the only one who has this problem. AI has claimed that recent windows updates may have corrupted the handshake nature of the USB4 Root Router etc and causes an alarm within and downfalls speeds to usb2.0 as a safe guard but certainly does the user no favours. Please if you may, direct me to a solution regarding this. There must be firmware or driver update in the works from microsoft perhaps. thanks , Moderator note: PII removed

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Answer 1

Welcome Glen Titanic,

Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.

I can understand how frustrating this is, especially after spending considerable time testing multiple readers, cables, BIOS settings, and even working with MSI and the device manufacturers.

Based on your description, it is difficult to conclude that the issue is caused by a Microsoft USB4 driver or a Windows update alone. USB4/Thunderbolt functionality depends on several components working together, including the motherboard firmware, Intel USB4 controller firmware, BIOS, chipset drivers, USB4 drivers, and the attached device.

Before suggesting further troubleshooting, could you please provide:

The exact Windows build number shown under Settings > System > About > Windows specifications.
In Device Manager, under System devices, what are the driver versions shown for USB4 Root Router and USB4 Host Router?
Does the same CFexpress reader achieve expected speeds when connected to another USB4/Thunderbolt 4 computer?
Are there any warnings or errors recorded in Event Viewer > Windows Logs > System around the time the reader disconnects or falls back to USB 2.0 speeds?

In the meantime, please try these quick checks:

Open Device Manager, expand Universal Serial Bus controllers, right-click any USB Root Hub or Generic USB Hub, select Properties > Power Management, and uncheck "Allow the computer to turn off this device to save power".
Go to Settings > System > Power & battery > Power mode and temporarily set it to "Best performance".
Visit MSI's support page for your motherboard and verify that both the latest BIOS and the latest Intel chipset/Thunderbolt or USB4-related drivers and firmware are installed. The motherboard vendor usually supplies firmware updates for the USB4 controller.
Test the reader with only the supplied certified 40 Gbps cable and no adapters, hubs, or docks connected to the USB4 port.

I look forward to your results.

Glen Titanic 0 Reputation points

2026-10-06T04:30:02.27+00:00

Thanks for your reply, here is the information as requested.

Windows Build, Windows 11 home vers 26H2 OS Build 26300.9550 Feature experience 1000.26100.9550

USB4 Root Router 1.0 driver and USB4 TM Host Router microsoft driver have the same driver ver. 10.0.26100.9549

The speed problem is documented with this motherboard "Pro Z890-S wifi P2 MS-7E58 ver 1.0. I am sure other manufacturers may not have this speed handshake problem. I do not have another computer to test USB4 Thunderbolt with.

The only errors were with the 60 seconds it takes to "somewhat" handshake and asign the reader a drive letter and mounting the reader,proving the intel host router firmware is failing its handshake and forcing a timeout reset. Also a rootport failure is evident of unstable triggers persistently causing a PCI Express route error in device manager which may indicate a systemic motherboard resource allocation failure and not a simple software issue.

The Pergear reader and card work flawlessly with my Lumix GH7 camera and reads and writes perfectly and at highest speed available when connected to the rear USB C 20gbps port which reads at half the speed of the Thunderbolt usb4 port capability. I am using Crystaldiskmark tool for read /write tests. This means the issue is strictly isolated to the MSI desktop native USB4 Architecture.

The USB4 Root hubs do not have power managementt tabs, and the those that do are USB3s which have a completely different Architecture than USB4 Thunderbolt.

System power is set to "Best Performance". I have already updated the current MSI Bios and Intel chipsets obtained directly from MSI support. MSI do not have any USB4 Controller update downloads as far as I know.

The Pergear reader is connected with proper 40 gbps 240v cables and stand alone to USB4 Thunderbolt rear port type C.

Thanks