4K External Monitor - Need advice

[Venga]

Hi guys,

Quick background, this set up is not for gaming, it is for design. It is for a home set up. Day to day at work i use a 27inch iMac Retina 2015.


I recently purchased a LG 27UD68P 27" 4K UHD IPS Monitor to use as an external monitor for my MacBook Pro Retina 15-inch Mid 2015.

http://www.lg.com/uk/monitors/lg-27UD68P

I am connecting the two by the Display Port of the Mac into the HDMI port of the monitor.

Yet the “best for display” is set to 1920 x 1080.

Is that right? It seems dated to be using a 1920 display. I was hoping to be able to use it at 2560 x 1440, the same as a iMac Retina display.

I have put it to 2560 x 1440 and it seems to run ok. The mouse seems slightly laggy though?

Will refresh rate make a huge difference?

Finally, could the connecting cable need updating? The monitor is said to be able to go to 60hz refresh rate but i don't have the option to set the refresh rate through display preferences?

Any advice on these issues would be greatly appreciated. Any more questions let me know.

Thanks in advance

[Gryffes]

Why not just use a displayport cable?


HDMI requires a 2.0 compliant input, output and cable to get 4k60 - the monitor is def hdmi 2.0, no idea if your output and cable are though.

The mouse feels laggy because 30hz sucks a dick.

[Isiolia]

Try holding Alt/Option when picking Scaled, which should show all resolutions.

Though, yeah, if the interface can't do high enough bandwidth, you'll be stuck at 30hz, which sucks. I would second trying with a displayport cable (Thunderbolt is pin compatible with mini-displayport, so you can just use that), since that can often be higher spec than HDMI on a given device.

[Venga]

Hi guys,

Thanks for the reply.

Switching to a mini display port to display port has fixed the issue. It is now running it at 60hz. However, i am unable to change the refresh rate, it is just automatically selected. Still, at least its defaulting to 60hz so can't complain!

Thanks again