Black border around display on second monitor - any ideas?!

In common usage, a device that supports ONE display is a display adapter, and a device that supports multiple peripherals is often referred to as a Dock.

That device says its limitations are:

The max resolution of the HDMI port is up to 1080p@60Hz & 4K@30Hz.

That Dock does not support the resolution you are using, although the Display itself claims to provide that resolution.

If you want to use that Dock, you should manually set it for the Dock's maximum, and see if the results are any different.

Nickolai001 wrote:

Hi there

Hoping someone can help me!

I recently decided to buy a separate monitor for working on my Mac Book Pro but weirdly when I connected the screen to my Mac the display comes with a black border around the outside of the screen and does not fit the full size (see pictures).

I have played around with the display settings such as changing the resolution, restarting the Mac with it plugged in etc and nothing has helped! It's currently connected to the display with HDMI to HDMI cable that goes into an adaptor (picture attached) that then goes into the Mac USBC port. I purchased a HDMI to DP wire and it's not recognising a connection at all.

Frustratingly my monitor only has 2 HDMI ports and 1 DP port - not sure if there are any other adapters/wires I could try with that limitation? There is not an issue with the display as it works perfectly normal when plugged into my Windows PC.

My specs for the Mac and display are below, any advice would be greatly appreciated. Thank you!!

Mac Book Pro 13" 2019 - macOS Big Sur

Acer Nitro monitor VG270S 27" https://ao.com/product/umhv0ees04-acer-nitro-vg270s-monitor-black-85325-258.aspx

https://discussions.apple.com/content/attachment/f6b4ab00-8e8c-41b5-922f-472c6b70e9cb

https://discussions.apple.com/content/attachment/6b44fed2-e6f0-4830-bf85-4a973c1839ff

https://discussions.apple.com/content/attachment/2c9994a6-3b03-43e8-abf6-64c60393c74a

Try using Extended Desktop Mode instead of Mirror Display Mode. Mirror display also mirrors the display resolution. Extended desktop mode allows you to select the native resolution of the external display.

Get help with video issues on external displays connected to your Mac -

https://support.apple.com/en-us/HT201177

Using the DisplayPort input to your display would produce better results and higher refresh rates at lower power than any HDMI solution.

here is an adapter/cable example:

Monoprice USB Type-C to DisplayPort 3.1 Cable - 5Gbps, Active, 4K@60Hz, Black, 6ft - Product # 24444 - $22.24

.

Please post a description or a link to the Dock you are using, and show in your pictures.