Flickering
can be caused by G-sync.
Does it flicker when G-Sync is turned off and/or have you installed this WIndows Update yet?
https://support.microsoft.com/en-us/help/4048955/windows-10-update-kb4048955This fixed most of my G-Sync issues if this doesn't do anything then I'd suggest to get a replacement.
Rampage V Edition 10
Intel Core i7-6950X @ 4.2 GHz
32GB Corsair Dominator Platinum DDR-4 2800
Windows 10 Pro x64
Corsair AX 1500i PSU
Samsung SSD 950 Pro m.2 512GB
WD Black 6TB
2x EVGA GTX 1080Ti FTW3 - EK-FC1080 GTX Ti FTW3 - Nickel
3x Asus PG279Q
Creative Soundblaster Z / Astro A50 Gen.3
Corsair K95 Platinum US - MX brown / Corsair Scimitar PRO RGB