Prime X470 Pro Issue

[Macmaniac]

I have a Prime x470 Pro with a graphics card in slot one and Sonnett 10G network card in slot PCIE 2. When I move that Sonnett card to slot 3 the system will not boot. It comes up and displays the Asus window and the ability to boot to bios but then stays there and eventually reboots itself. will not boot to Windows either. Any ideas what I can try? I have set the 3rd slot to 2 and 4x in bios from Auto. I have reset the CMOS and tested all but that configuration will not work. We do not have an M.2 card. When I move the card back to the PCIE 16x_2 slot it works fine. Thoughts?

Thank you.

[Jiaszzz_ASUS]

Hello, @Macmaniac 

Thank you for reaching out us.

Based on the specifications queried, the Sonnet Solo 10G PCIe network card has a bus interface specification of PCIe 3.0.
This indicates that when installed in the PCIEX16_3 slot at the very bottom of the PRIME X470-PRO, there may be compatibility issues due to differing specifications, as this slot is PCIe 2.0.
Please refer to the user manual on pages 1–6 of the PRIME X470-PRO if needed.

Therefore, we recommend that you install it in either the PCIEX16_1 or PCIEX16_2 slots.

Thank you.

[Macmaniac]

But I am finding that it should still be able to be installed. Might not perform up to specs but it doesnt even see it. Shouldn't we be able to at least see it? I don't doubt what you say but not seeing card at all whne inserted seems weird.

https://www.electronicshub.org/can-you-use-a-pcie-3-0-card-in-a-2-0-slot/#:~:text=So%2C%20the%20PCIe....