Triple Samsung Odyssey G7 (C27G75) issues

[edhunter]

Recently I have upgraded my sim rig to triple monitors using 3x Samsung Odyssey G7 (C27G75). And since then I started to experience strange issues:

- System freeze on wake from idle (sometimes)
- System freeze on boot (rarely)
- Random screen showing only black (sometimes)
- Some mouse stutters even on desktop, when I launch a program

So far I have, nailed down that the issue is related to the "adaptive sync" option. If I have it off on all monitors there is no problem. If I have it on, I experience some or all of the above issues.

Each monitor works fine when it is standalone. The problem is only when I use the monitors together.

Here is my setup:
gpu: RTX 4090 Gigabyte Gaming OC (stock bios)
system: Ryzen 5800x3d, msi x570 (latest non beta bios agesa 1.2.0.8), 32GB DDR3600, Windows 10 22H2
monitors:
  1x LC27G75TQSUXEN, bought used (still in warranty), connected via DP
  2x LC27G75TQSPXEN, bought new

So far what I have tried is:
- different DP cables, also measured that pin20 is not wired between both ends
- nvidia uefi firmware update tool for 4080/90, but it says "Already updated"
- updated my system bios
- reset my bios to defaults
- the usual DDU and new driver install (not that it can make something for the POSTS freeze)
- disable adaptive sync only on one of the side monitors
+ disable adaptive sync on all monitors - so far it's working

I dont really know where is the problem, but having adaptive sync off is not a solution - I need it on (these displays are being in official nvidia gsync compatible list).

Same system, but with my previous monitor, Samsung G9 (C49G95), never had any issue!

So, please help!

edit 2023-05-04, tried more things that did not help:
- clean install windows 11
- downgrade firmware on all monitors to 1014
- REPLACED the video card!!! from gigabyte 4090 to palit 4090

Still I have the same problems. 

[ddaniel51]

Considering you're running at max digital resolution for the 4090 perhaps you could decrease the refresh rate to give the hardware some breathing room.

[edhunter]

In windows I have set it to 120hz anyway since even 4090 is unable to maintain high frame rate in triple 1440p. But that does not change anything, some of the issues are even before entering windows.

[ddaniel51]

"Each monitor works fine when it is standalone. The problem is only when I use the monitors together."

Which points back at the supporting equipment.  Dual or triple 4090s??

Heck, even at 120 with Gsync off it'll look great!

[edhunter]

Singe 4090 - triple G7

Yes the problem might be also in the gpu, I dont know. I have a case with Gigabyte still waiting from them a reply.

[edhunter]

here is update:

I returned my old gpu (gigabyte 4090) and today I put new gpu palit 4090.
I enabled adaptive sync on my monitors, and guess what - on the first wake up I got machine freeze.

And btw I am with new fresh windows 11 installation.

So I am now 100% sure that it was not the gpu fault.

[edhunter]

And final update. I managed to test with another PC. Same happens with it too.

This is leaving only the monitors to be problematic. But I cannot find three other monitors to test.

[edhunter · Accepted solution]

Final update.

I am happy to say that the problem is solved.

I sold the monitors and moved to another brand triple monitors.