Monitor keep flickering; bad cable or bad GPU?

[Actual_Criminal]

I have a monitor that I have been using for about 6 months now and every so often, the screen starts flickering for a few minutes randomly (even when not under load, so it's not artifacting.)

I swap the Display port cable from one port to another and fixes the issue but restarts after a few minutes again... only thing that fixes the issue is shutting down and restarting my PC. I'm not overclocking my GPU or anything like that.

See some pictures of what the flickering looks like:





MONITOR: 34" ODYSSEY G5 LC34G55TWWUXEN, running at 165Hz at 3440x1440p
GPU: RTX 3090 FE
Display port 1.4 cables from Amazon: https://www.amazon.co.uk/gp/product/B08K2TLCD6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[Junk]

Could be either but most likely cable - but have you tried a different cable?

 

[Quartz]

Do you get flickering if you run it at 60 Hz? How about 100 Hz? With that refresh rate you're approaching (24.5 Gbps) the maximum data rate of Displayport 1.4 (25.9 Gbps) and Displayport cables get twitchy at long lengths.