Samsung Monitor Won't Show Top Resolution

Hi folks.

Just hooked up a Samsung U28R55 monitor and it won’t take full resolution. Here is the setup:

M1 Mini
	-> Left via HDMI direct to M1
	-> Plugable
		-> Centre via HDMI
		-> Right via DisplayPort

  Chipset Model:	Apple M1
  Type:	GPU
  Bus:	Built-In
  Total Number of Cores:	8
  Vendor:	Apple (0x106b)
  Metal Family:	Supported, Metal GPUFamily Apple 7
U28E590: (Left)
  Resolution:	3840 x 2160 (2160p/4K UHD 1 - Ultra High Definition)
  UI Looks like:	3840 x 2160 @ 30.00Hz
  Main Display:	Yes
  Mirror:	Off
  Online:	Yes
  Rotation:	Supported
  Automatically Adjust Brightness:	Yes
ASUS PB278: (Centre, rotated)
  Resolution:	1440 x 2560
  UI Looks like:	1440 x 2560 @ 60.00Hz
  Mirror:	Off
  Online:	Yes
  Rotation:	90
  Automatically Adjust Brightness:	Yes
Lu28R55: (Right)
  Resolution:	1920 x 1080 (1080p FHD - Full High Definition)
  UI Looks like:	1920 x 1080 @ 60.00Hz
  Mirror:	Off
  Online:	Yes
  Rotation:	Supported
  Automatically Adjust Brightness:	Yes

I’ve been through the menus twice and I can’t seem to get full res on this new monitor. Any ideas how I can fix this?


Hi BeeRich,

Thank you for contacting Plugable! Sorry to hear of these issues, but we’ll be happy to help investigate and find a solution.

When you have a moment, could you please let us know the following details:

  • The model of your Plugable device (located on the product itself, the box, and the quick start guide)

  • What is the exact Model of your Apple computer?

  • What version of the MacOS are you running?

  • Your Amazon/eBay/Walmart/Newegg order number from your purchase

  • If possible, a set of log files from your system, collected with the device connected. We have a tool that automates this process, which can be downloaded from:

Thank you for your patience and for giving us the chance to help!

Richard A
Plugable Technologies

OK, I shouldn’t really be posting this information on a forum in public like that. I’m taking this private.

Sorry, I posted this information to the email you sent as well.

This topic was automatically closed 20 days after the last reply. New replies are no longer allowed.