Second screen not working on DP

[HeXian68]

Good afternoon,

I am having an issue where I cannot use two screens at once

I tried plugging in each screen into the main HDMI, both worked all the way into windows

I tried plugging both only into the DP indivdually, and each one worked all the way into windows

I activated Rebar

I diasbled CSM, even though I need it for some things

The moment thaI tried to  have both, the second screen does not pick up signal and stays blank

My system

Arc B580 battlemage 12GB

ROG B550 MB

Ryzen 5 5600x

32GB 3600 DDR4

Please help, only 1 screen is driving me insane

[Dan682Lee]

Hello!

Since both monitors and ports work independently, the issue is likely a handshake failure between the Intel Arc B580 and your B550 motherboard. First, ensure you are using Active Adapters if converting signals (e.g., DP to HDMI), as passive ones often fail on Arc cards. Try lowering both monitors to 60Hz in Windows Display Settings to see if they stabilize, as mismatched high refresh rates can prevent initial detection. Additionally, in your ROG BIOS, manually set the PCIe Slot Mode to Gen 3 instead of Auto/Gen 4; this often resolves bandwidth sync issues for Arc users on the AM4 platform.

[HeXian68]

Thank you very much for commenting, it is appreciated

I will try this when I get home and let you know know how it went