I recently just got my new Asus Strix 480's and i'm enduring screen flickering with my BenQ XL2411Z, connected by DVI cable, when running at 144hz. I don't have any screen flickering when I lower it to 120hz and below.
I also just faced a random black screen this morning a few minutes ago. Out of know where, just sitting at desktop idling with nothing running (second card was in ULPS), the screen just went black. My monitor was still on, its LED stayed green instead of going orange as if it was in sleep mode or completely off. I tried to turn it on and off again to no avail. I also disconnected the DVI cable from my 480 and reconnected it and it still stayed black. The only way to get it to display normally again was to press my power button on my computer which caused windows to shutdown normally.
also want to add it didn't appear that my computer froze as again I was able to shutdown the computer normally by pressing the power button and I was able to move my mouse around and click things because I heard the windows charms as I blindly, randomly, clicked things. The monitor didn't "lose" signal since its LED stayed green and the backlight didn't turn off. It was still at full, normal brightness with a very bright "black" screen.
I have two Asus strix 480's running in crossfire, and i did swap both cards as primary and secondary and the screen flickering still happens. If the black screen happens again I will swap the cards around once more to see if that fixes it. Though from a quick googling I see a lot of other people complaining about both the screen flickering and black screens with their 480's since launch.
I'm running the following:
Windows 10 64bit education build 1607 (complete fresh reinstall from a newly downloaded ISO from EDU dreamspark and installed from scratch on a new ssd)
Asus Sabertooth Z170 S (bios 1801 as 1901 breaks my ram XMP profile)
Intel Core i7 6700K (1.35v's @ 4.2ghz)
Corsair DDR4 3000 32GB Cas 15 (2x16GB)
Evga SuperNova P2 750 (750 watts should be more than enough for both cards and ran my old 970's in SLI just fine, though the black screens happened at idle and not load (yet))
Asus Strix OC 480 (STRIX-RX480-O8G-GAMING) x2
Sound Blaster ZX
BenQ XL2411Z on DVI