Randomly sometimes not ! I see those red blinking lines comes and goes suddenly ! I tested a gtx msi 1080 ti gaming X , I bought another 1080 ti Asus strix because I thought it was faulty and same happened again, Brand new pc no OC done with a fresh win 10 genuine format using a 60 SSD ( tested again on a regular WD 3TB HDD ) and the same
Gpu temp idle 40 - Max load 65 Degree CPU 30 idle - 60 degree Load
here tested on 2 gtx 1080 ti tested on 660 and no signals
Oh man -I'd place a bet that it's your panel- because its happening in the same spots/shapes. Looks like it may be going bad.. Do you have another monitor to try?
I've seen that kinda thing before on dying LED and LCD panels..
If you rule out the card or drivers..the only thing that would really cause something like that would be wonky power delivery..maybe, or the panel dying,, because it doesn't look to me like a software glitch.
PSU = first super critical thing people sometime don't consider and/or skimp on.
Monitors = a close second I would say.. Not saying you specifically...just the way it is.
EDIT: ** You have a nice PSU!..meant to lead with that.**