Have you tried each monitor independently ?

Yes, ive tried the monitor by it self and still same problem. Though it only happens about a couple of hours away from each other. Also, i've tried using other cables and still same result. :/

The creep to white tends to start from the top of the display and works down to the bottom in a sweep, just like the vertical refresh.
 
-LCD's inherently transition to white whenever pixels aren't updated for a good deal of time.
 
In my past experience it's usually is something like the scaling circuitry dying, and not the panel itself..  You could always try a shorter cable or heavily shielded one, yet I don't think it'll make a difference honestly.  Most displays will report signal loss if it's off long enough for something like this to happen, if they're properly working.
 
If you have an IR thermal probe, you might see if you can find any hot-spots on the display, if you do (because 4KHD scaling is alot of work) --- it may be possible to cool the monitor down.  Should it be heat related.
 
EDIT: It may suck to do while gaming, yet for testing literally I would take out a box fan and blow it on the back of the display.  If the display starts acting stable, then at least you'll know what the problem is if you attempt homebrew modification later on (eg, cutting the back casing open and installing a cooling fan over the scaler).
 
Of course, always RMA if under warranty first.
 
EDIT 2: Can the fade to white occur during motion / updating of pixels?  Or for instance are you primarily seeing it when sitting on the desktop for a display?  I mainly just am curious if the panel's image "freezes" for that second and a half.

cdc-951
It is the board in the monitor ^^^ I can confirm this is the problem since I called Acer and this is a semi wide spread issue, we can consider his issue to be answered now @MasterGohan

Yeah, I had problems with a 1600p 30" Gateway brand monitor just like what was described here.
 
 
In my case a screen freeze + whiteout intermittently.  I RMA'd, got it replaced, and my second, third ... fifth, RMA's all failed.  Eventually on the 6th time (getting tired of paying the return shipping) I gutted my display's case, placed RAM heatsinks on the scaler board, and mounted a 120mm fan blowing cool air in the back to help ventilate it.
 
-That was the only permanent solution to stop it from baking.  Later on the screens were removed from the market and stopped being sold due to the defect.  On a few of the times that this started happening, I actually smelled that burning electronics scent too.