Flickering pixels on monitor

geertsch

macrumors newbie
Original poster
Oct 15, 2016
2
0
I use an extra monitor Acer G277HU to my Imac 27 inch 5K. On the extra monitor i see tens of flickering pixels.
When i link it up to macbook pro (also via HDMI-tunderbolt)...the imag on the monitor is perfect.
I tried changing resolution....color profile...rescaling but noting works.
Can somebody solve this problem?
many
thanks
geert
 

maflynn

Moderator
Staff member
May 3, 2009
63,856
30,378
Boston
Sounds like maybe the iMac is having problems driving the other monitor

What GPU does your iMac have?
 

geertsch

macrumors newbie
Original poster
Oct 15, 2016
2
0
I use an extra monitor Acer G277HU to my Imac 27 inch 5K. On the extra monitor i see tens of flickering pixels.
When i link it up to macbook pro (also via HDMI-tunderbolt)...the imag on the monitor is perfect.
I tried changing resolution....color profile...rescaling but noting works.
Can somebody solve this problem?
many
thanks
geert
[doublepost=1476534812][/doublepost]LEGEND
iMac5K M395X = 'late 2015' iMac Retina 5K 4.0GHz Quad-Core i7; Radeon R9 M395X GPU (4G GDDR5); 16G RAM; 1TB flash storage
 

maflynn

Moderator
Staff member
May 3, 2009
63,856
30,378
Boston
You have the high end dGPU, so there's no reason why it can't drive both of them
 

rshrugged

macrumors 6502a
Oct 11, 2015
895
627
Eject and remove any attached peripherals, if applicable, to see if there's any improvement.

If you haven't already, use the same mains supply when testing both scenarios to eliminate the possibility of line "noise" as a cause. Also consider any power strip, UPS or other extension product that's between the machine and the mains.