Neo G8 4K 240Hz losing connection randomly for 1-2 sec

[Byogore]

Have a problem that kind of makes no sense to me. I swapped from an RTX 4090 Suprim to 5090 FE and now the monitor randomly turns off for 1-2 sec and recovers. Tried 3 different cables (Silkland DP 2.0 and IVANKY) also the default cable. All of these cables worked fine before. I am using the latest firmware.

The monitor wasn't even used once after I sold the 4090. I just plugged it in after a month. When using GSYNC, this blackscreen never happens. When you turn off GSYNC (aka adaptive-sync on the monitor's settings), you lose connection to the monitor for 1-2 sec whenever it feels like it. Could be 1 minute, 15 minute or 30 minutes. This happens on desktop and in games. Monitor goes black and in the top left you can see the Display Port icon, as if I manually reconnected. Stock 5090 settings.

I never once had this issue before. Windows is fresh, DDU drivers, tried the last 4 drivers and it still happens on 572.83. I also tried the 1080p 240Hz BENQ that I have here and it didn't cause any blackscreens (didn't test it much tho) but I am guessing this is a driver issue with DSC and for some reason GSYNC makes it work (even with uncapped FPS)

So what do I do now? RMA the monitor or is the GPU broken? It's hard to tell what's happening here. The GPU works fine under any stability test (3DMark etc) with max OC, heavy undervolt and also stock. Tried all ports (except HDMI since I don't have an HDMI cable atm but will soon)

Waiting on a SILKLAND 2.1 DP cable and also HDMI 2.1 so I can test the HDMI port. Will also test plugging the monitor in the 9800X3D's iGPU to see if the blackscreen happens there, tho I am not sure if I can even run 4K 240Hz on that.

What a frustrating issue. Specs below

CPU: 9800X3D

GPU: RTX 5090 Founders Edition

Motherboard: X870E Nova (3.15 BIOS) and using PCIe x16 5.0 (tried 4.0, still the same thing)

PSU: NZXT C 1500W

I am guessing this is some weird DSC driver bug.

[Samsung_Moderator]

Hello! Thank you for reaching out! I would recommend reaching out to NVIDIA about a firmware update, as this card is so new. I would so to test it again with your other card if you still have it, to see if this still occurs, but it seems like you sold it. 

[Byogore]

Unforunately I don't have the 4090 anymore. I'll try reporting it to NVIDIA as well. Is there a specific place to do it?

Also, are there any report of this at Samsung, or perhaps the monitor / GPU are broken. Been using it for over a day with "Adaptive Sync" enabled on the monitor (even with gsync disabled in NVCP, on or off there doesn't matter) and the monitor never disconnects that way.

[ShadowCreek]

I have the same issue going from a 4090 FE that worked without issue to a 5090 FE. current temp fix is to set the refresh to 120hrz. will more than likely be a firmware update for the 5090 FE or and driver update.

[Byogore]

Wonder if they're aware of this issue at all. 120Hz also works, yeah. I prefer to use 240Hz tho, so for the time being, I'm going to keep "Adaptive Sync" aka GSYNC on since that prevents the monitoring from disconnecting all the time. Does your monitor work at 240Hz / no black screens when Adaptive Sync / GSYNC is enabled? If you could test that for an hour or so, that'd be nice. Then we would know for sure that it's a driver bug. I don't mind waiting for a fix, just need to know where this bug is coming from.

I reported the bug to NVIDIA. No idea if they read messages.

[ShadowCreek]

At 240hz with adaptive and g sync enabled is when i have the issue. Also my monitor firmware is at 1011.3 so most up to date.

[Byogore]

So it's the opposite for me. I have the issue without GSYNC. Really makes no sense. I'm also using the latest firmware. I was on 1006 or something like that before.

[ShadowCreek]

I have a dual monitor setup the second monitor runs off of the 9800 X 3D igp. If the monitor was at fault and disconnecting from the video card, then my second monitor would shrink on Windows 11 that symbolizing a monitor disconnected along with the sound. And then would reinitialize the connection when the monitor came back. But this is not the case the video card still believes that the signals going out but the monitor does not have the proper data and loses the signal this is why I believe that definitely the issue is the GPU 5090. That and the 4090 worked its whole life without a single

[Byogore]

My plan is to also test the 9800X3D iGPU. Do you know if it can run 4K 240Hz? Because the issue doesn't happen on 120Hz, so unless I can test 4K 240Hz, it would be kind of useless. The monitor is fine with GSYNC or 120Hz on the 5090.

But yeah I think this is a driver issue. If the card or the monitor were broken, the issue would also appear with GSYNC on. I guess GSYNC for me (and for you the opposite) does something with the drivers that makes it not disconnect.

Now the real question is: will they ever fix this? Probably not even aware of it.