Display port issues with the Predator x34

I don't have a solution for you, but I have one thing you possibly could try if you haven't already.  I've been struggling with a similar problem with the DP connection.  In my case, getting to my windows desktop using the DP cable takes a long time.  A really long time.  It may be related to your "no display" message in that just nothing seems to be happening onscreen.  I get the windows logo and it's just stuck there for a good 2 minutes until finally it "wakes up" and I get the whirling circle and then onto desktop.  My previous monitor using DP took 27 seconds to get to desktop. 

I've spent the last 10 days reading and researching on the net.  I've disabled nearly everything in my start-up folder, uninstalled programs, ran diagnostics, bought and tried different certified cables.  I did read posts where it seemed there might be some merit to the fact that a good number of Maxwell architecture video cards are having DP-related problems with this monitor.  And I think you've found that to be true, as you had no problem with your 1080 card.  And even the 770 video card ran it fine (I think that's a Kepler card?). 

I am coming up to the end of my 30-day return window, and I had been struggling with wondering if it was a problem with my system, my video card (a Titan X Maxwell), or a faulty display port on the monitor.  And if it was a faulty port, I needed to return this while I still could do so.  Your experience seems to confirm that it might well be more of a video card issue and I can safely keep my nearly perfect Predator, knowing that within a year or so I'll be getting a new card.  In the meantime, I can turn my computer on from a cold boot and walk away...go make coffee..and when I return it will be at the desktop and ready to go.  Once I'm at the desktop, I have zero problems.  No black outs, no signal loss, no flickering.  I'm at 100 Hz and ready to rock.

Anyway, one little thing you might try (and like I said, I've tried everything under the sun).  Plug your DP cable into the first DP port--the one closest to your motherboard.  Get to the desktop however you can...via your little workaround with the HDMI if you have to...but just get to desktop and then do your switch to DP to make that your active monitor. 

Go to your Device Manager.  Click on View and then click on SHOW HIDDEN DEVICES.  Look at Monitors.  I suspect you'll have one bold (active) monitor...Acer (DP)...along with a bunch of grayed-out monitors.  Right click each grayed-out monitor individually and choose to UNINSTALL.  Do that for each one until you're only showing Acer (DP) as your one monitor.  Then close down your computer.  Remove your HDMI cable and only use the DP cable. 

From a cold boot, start up again.  Even if you get a "No Signal" message, just let it do its own thing.  Seriously.  Walk away for 5 minutes.  When you come back, if it's still a black screen, then it's obvious this is not the magic bullet solution for you and you'll have to do your HDMI workaround, get a new video card, or return the Predator.  But it's possible that your Maxwell card--like mine--is just extremely slow to communicate with the monitor and it will take longer as it cycles itself through no signal/signal/no signal.  Something else to try.  LMK how it goes.

Sorry it didn't help at all.  I know firsthand how very frustrating this is, with no one offering even unhelpful suggestions much less an outright solution.  I know I've done all I can...I feel I'm married to my event viewer at this point; I'm constantly checking it for clues.  But at least I know my system is streamlined, and you've actually reassured me that the monitor performs as it should with any video card other than a Maxwell-based one. 

Were you planning on returning it?  Or replacing your video card?  I had wondered if the ASUS PG348Q would work, but it is the same panel so I guess it's doubtful.  Wish I knew for sure, though.  I have 5 days left before I'm out of my return window.  Love the monitor otherwise; no scan lines, no coil whine, no dead pixels.  But that loooong cold boot irks the heck out of me!