ARC B580 Display Port not working after POST

[pens]

Hello,

I have a new Intel Branded ARC B580 that has been having an interesting Display Port Issue. When plugged in via display port the system will show the motherboard post screen, as well as the windows loading splash screen with the motherboard manufacturers logo. 

Once windows has loaded the card will spin the fans up for an aggressive second then provide no output. The monitor will flash as if attempting to wake from the black powered off state to grayscale for a second, then back to black. This repeats about every 3-5 seconds in loop. Plugging in via the HDMI Port causes no such issue and the card seems to run perfectly fine. Additionally, the system worked fine with the current monitor and cable on the previous GPU, an AMD RX5600XT.

I have attempted the following troubleshooting steps before reaching out:

1. Tried two different display port cables

2. Tried all three Display ports on the back of the card

3. Tried using a different monitor, with both of the different cables mentioned in step one (Links to the two monitors; Original Monitor: LG 35WN65C https://www.lg.com/us/monitors/lg-35wn65c-b-ultrawide-monitor Additional Monitor Tested: Samsung CF791 https://www.samsung.com/us/computing/monitors/gaming/34--cf791-wqhd-monitor-lc34f791wqnxza/)

4. Running DDU to remove old AMD Drivers before installing Intel Drivers

5. Running DDU to remove Intel Drivers and reinstall fresh

6. Confirm Motherboard Bios is up to date

7. Confirm ReBAR and Above 4G Decoding are enabled in BIOS

8. Updated Windows

It appears to me that their is a driver issue since the graphics card works perfectly fine on the post screen and the windows loading splash screen but no longer displays once loaded into Windows. To reiterate, the card works completely as expected over HDMI with both monitors tested, but any use of Display Port causes the issue described above. SSU attached, any support is appreciated!

[VonM_Intel]

Hi, pens.

Thank you for posting in our Community and for the detailed breakdown of the issue and the extensive troubleshooting you've already performed. Your methodical approach is highly appreciated and gives us a solid foundation for further diagnosis.

Based on this, it strongly suggests a possible driver or firmware-level conflict specific to DisplayPort functionality post-driver handoff. To move forward effectively, I'd like to gather some additional information and perform a few further checks:

• Did this issue occur straight out of the box, or was the system functioning normally prior to this? If it started after a driver update, could you confirm the driver version that previously worked (if any)?
• Have you tried resetting the BIOS to its default settings? 
• Was the refresh rate manually adjusted in Windows or the monitor's OSD menu? Some ultrawide monitors, especially at 100Hz+, may behave inconsistently via DP if Windows defaults to unsupported refresh timings.
• Was a custom refresh rate previously configured or enabled? If yes, what happens when the refresh rate is manually reduced (e.g., to 60Hz)?
• When HDMI and DP are connected simultaneously, does DisplayPort output appear in Display Settings or Device Manager? Any detection event there would be useful. 

I understand there are several questions, but identifying the root cause often requires us to explore multiple possibilities to ensure nothing is overlooked.

Have a nice day!

Best regards,

Von M.

Intel Customer Support Technician

[pens]

Hi Von,

Thanks for the quick reply! I answered your questions below:

1. This occurred straight out of the box, I have only used this card with the most recently published drivers

2. I have not performed a full CMOS reset, I rolled the board back before updating the bios to the current version prior to installing the card however. It is my understanding Asus did not enable ReBAR support until the later BIOS versions of this board, hence why I have been hesitant to roll back unless advised.

3. I went through and checked each of the refresh rate options on the LG monitor (84.98, 60, 59.97, 59.94, and 50)  in windows by adjusting it with the HDMI plugged in, then attempting to reboot with Display Port. None of the above changed the symptoms. I did not see any options on the monitors OSD to adjust the refresh rate. I did attempt to enable and disable FreeSync on the monitors OSD but even over HDMI windows and the Intel Graphics software do not recognize Variable Refresh Rate as supported. Neither on nor off on the monitor allowed it to work via Display Port.

4. This had an interesting output. I connected the displays in the below configurations after setting them both to their highest possible refresh rates in windows via HDMI, I also tested variations of enabling and disabling FreeSync on each monitor as listed:

A. LG monitor HDMI - Samsung monitor Display Port - FreeSync enabled on both: Surprisingly output on both monitors and correctly stated refresh rates in windows. Samsung monitor showed Variable Refresh Rate enabled, LG did not.

B. Samsung monitor solo Display port - FreeSync enabled: Now works perfectly, testing previously it displayed the same symptoms as the LG but after being plugged in at the same time as the LG it now seems to work under all conditions

C. LG monitor DP - Samsung monitor HDMI - FreeSync enabled on both: Samsung monitor works as expected, all settings showing as expected, LG monitor shows same symptoms as originally seen

D. LG monitor DP - Samsung monitor HDMI - FreeSync disabled on both: same results as C.

E. LG monitor solo Display Port - FreeSync disabled: Still showing original symptoms.

Following above tests I then tried to do as you  requested, plugging both monitors in via display port, Samsung on the primary outlined port and LG on the port closes to the HDMI port. Samsung working fine, The LG still shows the same symptoms as described originally. When going into Windows Display settings however on the Samsung I can see the LG monitor existing, and unlike via HDMI I can see that it supports variable refresh rate and that it can be set to its max ~100hz. I attached a picture to show what Windows is seeing when both are plugged in via Display Port.

A last point of interest is that if I try and change the refresh rate of the LG monitor in windows at this point with both plugged in via display port to anything other than its max, the monitor stops doing the attempt to wake cycle and is instead displaying a static image of gray vertical 'artifacting' bars across the entire display. Changing back to the max refresh rate in windows removes the artifacting and returns to the original symptoms.

So now the issues seems isolated to the LG display, does that lead to a likely Firmware issue?

[VonM_Intel]

Hello, pens.

Thank you for the comprehensive and methodical update. This level of detail is incredibly helpful and shows just how thoroughly you've approached this issue. Based on the extensive testing you’ve performed, your analysis appears well-founded. Given that the ARC B580 functions correctly with the Samsung monitor over DisplayPort, and that the LG monitor only exhibits issues when connected via DisplayPort (while working as expected over HDMI), it does indeed suggest a compatibility issue likely rooted in the LG display’s DisplayPort firmware or EDID behavior, particularly in how it negotiates refresh rates and VRR settings with the ARC driver stack. The behavior you observed, where lowering the refresh rate introduces visual artifacting while the maximum refresh rate restores the original wake loop, further supports the hypothesis that this may be a timing or handshake issue related to LG’s DisplayPort implementation, especially in conjunction with VRR.

In the meantime, I will need to perform further investigation into this issue and will provide an update in this thread as soon as I have additional insights to share.

Best regards,

Von M.

Intel Customer Support Technician

[VonM_Intel]

Hello, pens.

Thank you for your continued engagement and for the details you've already provided. In order to better understand and address the DisplayPort issue you're encountering with your Intel® Arc™ B580 graphics card, I kindly request a bit more information to help me narrow down the root cause:

1. Could you please share the brand and model of the monitor you’re using?
2. What is the current resolution and refresh rate set on the monitor?
3. Can you provide the brand, model, and version (if available) of the DisplayPort cable(s) you’re using?
4. Are you currently using a single display or multiple displays in your setup?

Having this information will allow me to better align our support and identify any potential compatibility variables.

Best regards,

Von M.

Intel Customer Support Technician

[pens]

Hi Von,

Answers to your questions can be found below:

1. The monitor is an LG Model No. 35WN65C-B
2. The Resolution is 3440X1440. On HDMI the refresh rate is maxed at 84.98Hz and on DisplayPort it is 99.98Hz
3. I have tested two DisplayPort cables. The first is a Hwasung E494210-E and the second is a Samsung BN39-01879L
4. Currently using a single display and the goal is to run the system on a single display in the future.

Let me know any other information I can provide, thanks!

[VonM_Intel]

Hello, pens.

Thank you for providing the detailed information. This is exactly what I needed to move forward effectively. Based on the monitor model (LG 35WN65C-B), the resolution, and the refresh rates you've listed for both HDMI and DisplayPort, your setup appears to be well within expected parameters. It's also helpful to know that you've tested with two different DisplayPort cables and that you're running a single-display configuration, with no plans to expand beyond that. At this point, no additional information is needed from your end. I’ll review these details further to determine the next best steps, and I’ll circle back with an update shortly.

Appreciate your continued collaboration, please feel free to reach out if any new developments arise in the meantime.

Best regards,

Von M.

Intel Customer Support Technician

[VonM_Intel]

Hello, pens.

Thank you for your patience in this matter. Since you've already completed several isolation tests, the next recommended step is to try testing the Intel® Arc™ A580 graphics card in a separate, known working system to help rule out any platform-specific issues. Additionally, may I kindly confirm if you've verified the functionality of your monitor(s) and display cables on another known-good setup? If your motherboard supports DisplayPort (DP) via internal graphics, I also suggest testing using only the integrated graphics to further isolate the issue.

If you do not have access to another system for further isolation, please let me know, and I’ll check internally for possible options.

Best regards,

Von M.

Intel Customer Support Technician

[pens]

Hi Von,

Sorry for the delay. I unfortunately am unable to test the B580 on another good system as my second rig is mITX based and too small to accommodate the card.

I was able to confirm the display does work on my other system as expected using both display port cables.

Lastly unfortunately this system does not have a display port out on the motherboard. The HDMI out on the motherboard does work however if that's relevant.

[VonM_Intel]

Hello, pens.

Have you had a chance to review my previous response? Please let us know if you require any further assistance. I'm here to help.

Best regards,

Von M.

Intel Customer Support Technician

[VonM_Intel]

Hello, pens.

Thank you for the update, and no worries at all regarding the delay. I appreciate you taking the time to test the display cables and confirming their functionality on your other system. This is helpful in narrowing down the issue. Understood on the limitations with your mITX system and the absence of a DisplayPort on the motherboard. The fact that HDMI out from the motherboard works is definitely relevant, as it confirms onboard video is operational and helps isolate the issue further.

In the meantime, I will need to perform further checks on this and will get back to you as soon as I have additional information.

Best regards,

Von M.

Intel Customer Support Technician

[VonM_Intel]

Hello, pens.

Thank you for the detailed information and for performing the majority of the recommended troubleshooting steps. At this stage, I recommend proceeding with a swap test to fully isolate whether the issue lies with the graphics card itself. If possible, please test the card in a known working system to verify if the issue persists. Additionally, kindly check whether the card is labeled as LE (Limited Edition), as this may be relevant for possible warranty processing.

Please let me know if the issue remains.

Best regards,

Von M.

Intel Customer Support Technician