iMac Secondary Display Help

ray6athome

macrumors newbie
Original poster
Nov 29, 2018
1
0
I'm wondering if someone can help me out with this predicament.

I recently picked up a BenqQ GL2706PQ QHD monitor with 2,560x1,440 resolution to be used as a secondary monitor for my late 2015, 21.5" 4k Retina iMac.

My problem is getting the secondary monitor to display in 2560x1440 resolution. Currently, the highest I can get the monitor to is 1080x1920. I currently have the monitors connected with a random HDMI to Mini Display Port cable i found in my box of cables. I believe this may be the issue and I'm looking for what the correct cable to get is. A direct link to a product will be awesome. In addition to the HDMI, the secondary display also has a dvi-d and dp port. Any help would be awesome.

Thanks in advance.
 

theluggage

macrumors 601
Jul 29, 2011
4,035
2,717
I believe this may be the issue and I'm looking for what the correct cable to get is.
(Disclaimer: haven't tried your particular Mac/Display combination)

Yes - older DP-to-HDMI adapters max out at 1080p or 1920x1200.

A newer DP-to-HDMI adapter is one solution - get one that's advertised as supporting 2560x1440. I have (I think) one of these: https://www.startech.com/AV/Displayport-Converters/active-mini-displayport-to-hdmi-adapter-white~MDP2HD4KSW - and it was able to drive up to 4k from my 2011 MBP.

However - since the display has DisplayPort I'd start with a MiniDP to full-sized DisplayPort adapter which should be cheaper, as its a passive cable: e.g: https://www.startech.com/Cables/Audio-Video/DisplayPort/3foot-Mini-DisplayPort-to-DisplayPort-Adapter-Cable-Male-to-Male~MDP2DPMM3

There's always a bit of uncertainty with these things so I'd always start cheap and work up unless someone confirms success with your exact hardware :)
 
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mikehalloran

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