15h ago

Question about screen distortion on external monitor.

I use a windows computer for work with a usb-c to HDMI hub.

I needed to use my wife’s m1 air, and there was weird distortion on the screen. It was minimal, but noticeable.

I read that this can be a problem with m1 and m2 air models. I plan to get an m4 air in the next few months and I’m wondering if this model has any screen distortion problems on an external monitor.

I do not have distortion problems with any of my other computers using the same hub and wires, so I don’t think it’s a problem with them.

7 comments

Did you check Settings > Displays to see if changing the screen dimensions or refresh rate made any difference?
- Yeah, I tried the different refresh rates and it didn’t make a difference. Other people with the m1 have reported this issue online, so I was wondering if it affected m4 machines as well.
- Yeah, I tried the different refresh rates and it didn’t make a difference. Other people with the m1 have reported this issue online, so I was wondering if it affected m4 machines as well.
What kind of distortion? So you have a picture?
Is it blurry? Are there digital artifacts randomly? Does it just blank out then come back?
- It’s a hard to describe, but it’s like faint lines running through the display horizontally. Hard to see on dark backgrounds.
  
  And it's only on her M1 and not any other machine?
  On my display I have at home I have a kinda similar issue, but it's on all machines. It's just only noticeable on Mac OS with the default colors the theme uses. On 100% white it's too blinding to tell, any darker and it blends in. The "lines" are the border between the pixels and as far as I can tell it's because the display has a poor "dot pitch" for it's size.
  They're still there when I connect a PC, but like I said it's harder to tell with the theme Windows uses, but they're still there.
  
  I get something like what you’re describing with my M3 Air when using an Anker 555 hub to connect to an external monitor via HDMI. Most of the time it’s fine, but occasionally I will get a distortion/interference effect on the external screen, kind of like rolling horizontal bars or flickering. Sometimes quite subtle, other times very distracting.
  I’ve tried swapping out cables and repositioning devices in various configurations: it’s not the cables, and other devices don’t exhibit the same issue when displaying through the same hub.
  I’ve also noticed that certain patterns onscreen cause it to happen more easily - checkerboards and fine diagonal stripes in particular. Very odd, and means there are some websites and apps that can semi-reliably trigger it.
  I almost wonder if it’s something to do with how macOS is scaling the image for the display, and that not playing nice with the hub’s HDMI encoder for some reason?

7 comments