Dark Hero Z790 Problems

[Lazarosgr]

Hello. I have just bought a brand new Z790 Dark Hero. I have 64 gb (2x32)Ram from vendor list, 13900KS, 1600 corsair Platinum PSU, 4080 RTX.
The first issue i have is the extreme slow usb speed(front and rear). For the samsung ssd usb-c the maximum speed read/write are the 35 MB/", for sandisk extreme card (with adapter) is 30 mb/", even from my  drone using 1 gbps usb-c is the same.
Tried the specified items in another machine and the speed were day and night. For the samsung i have 600 MB, for the card reader 160, for the drone above 1000. So i tried another set of cables but no result.
!!!!!!!!!!!!!!!    Bios & Windows & drivers are all up to date. !!!!!!!!!!!

The second issue i have is when i turn off the psu for some hours, the machine has a dead start for 2 minutes. Then it prompts me to bios and wants to save and exit default settings.

The situation gets me crazy. The motherboard is only 4 day old.

P.S. I tried the setup to another case (from corsair 8000D to 9000D), to test the front cables, but i have the same problems.

[Jiaszzz_ROG]

Hello @Lazarosgr 

Thank you for reaching out to us.
Could you please confirm whether you have updated the BIOS to the latest version 1801 and cleared CMOS? Have you updated all relevant drivers provided on the ROG MAXIMUS Z790 DARK HERO support page, including the chipset driver?
Meanwhile, please refer to [Windows 11/10] Change Power mode and plan and ensure that the power plan is not set to power-saving mode and that there are no restrictions in the advanced power settings
Regarding the issue where the system enters BIOS after turning off the PSU for an extended period, we recommend restoring default settings. 
Could you provide details on any manual BIOS adjustments you have made? If memory overclocking is involved, kindly share the complete memory part number and the slots currently in use.
At the time of the issue, were any external devices connected? If you remove all external peripherals and attempt to boot again, does the system still go directly into BIOS?
Additionally, we recommend referring to the ROG MAXIMUS Z790 DARK user manual to verify that all hardware components are correctly installed in the recommended slots or positions, and also check that the CPU pins are not bent and that the installation is neither too loose nor too tight.

Thank you.

[Lazarosgr]

i have done again and again, what ever you say. 
Bios defaults, upgraded, downgraded, upgrade one last time
Clean installation Windows 11 pro, all updates, all drivers, no tweaks, nothing. 

[dennys2009]

Hi!
1. Disconnect all SATA and SSD hard drives from the motherboard, leaving only the system drive from which the OS boots.
2. No BIOS settings can slow down USB 3.1 and USB Type-C ports. Therefore, either there is a device conflict, or some PCi-ex lines cannot distribute devices among themselves, or this is a defect in a specific instance of the motherboard.