Dell D3100 Dual 1440p Monitors
 

Hi there,

I have a Dell D3100 dock connected to my Macbook Pro 15" Retina Late 2013. I have 2 Acer K272hul 1440p monitors.

I'm having issues getting the full 1440p resolution on the monitors when connected to HDMI. The monitor connected via Displayport works at full resolution but when I try on either of the HDMI ports with various different HDMI cables it maxes out at 1080p.

I've even removed the displayport connected monitor but still no luck. I've installed, reinstalled the drivers etc a few times and have restarted my machine loads to no avail.

When I go to "About This Mac" and click 'Displays' it seems to show the HDMI connected monitor as 30.5inch with max resolution of 1920 x 1080 - even though it's a 27" monitor.


UPDATE: Displaylink driver 5.2.1 Beta has fixed this problem! ����

Still no luck with this :( Anyone got any ideas?

According to this document from Dell --> https://www.dell.com/support/article...tation?lang=en the maximum resolution supported by the HDMI outputs when two HDMI displays are connected is 2048x1152 (you will have to scroll all the way down to see this information). Most displays do not have support for such resolutions, so as a result the displays are most likely using the more common 1920x1080 resolution as a fallback.

To put that another way, it would appear the behavior you are seeing is an internal hardware limitation of the dock itself.

Hi thanks for your comment. Yeah I'd seen that, but it states the maximum resolution is 2048x1152 only when two HDMI outputs are connected. The way I've got it setup is 1 monitor is connected via Displayport and the other monitor is connected via HDMI.

The Dell table states that the HDMI outputs can output to a single display at 2560x1440 resolution, but at a maximum 50Hz refresh rate (which is lower than the typical 60Hz).

Looking at page 18 (printed page 8) of the manual for your display (https://www.acer.com/ac/en/US/conten...oduct/5218?b=1) , there is no EDID timing for 2560x1440@50Hz, but rather only support for 2560x1440@60Hz (screenshot attached).

The absence of this timing mode is most likely why the display is dropping down to a lower resolution.

Hmmm good research - but both monitors work fine through the D3100 when I use a Windows 8 laptop, so it seems like some MacOS compatibility issue unfortunately. I've emailed Displaylink support with the info and logs to see if this can be solved. In the meantime I'll use the HDMI out on my Macbook for the second monitor! Thanks for your input :)

If you have had success with the same physical setup using Windows, if you have not already you may want to try the procedure described here --> https://support.displaylink.com/know...-not-available to see if that allows you to manually specify the resolution of the display within macOS.

Yeah I've tried that also but still no luck!

UPDATE: Displaylink driver 5.2.1 Beta has fixed this problem! 🥳🥳