iMac 2020, 5700XT - graphical glitch?

[Theon123]

Do you use bootcamp for running Windows Desktop apps or only games?

I have mostly been using windows for both. I am still getting used to MacOS as I‘m a windows guy. Girlfriend is a Mac user which is the reason we picked up the iMac.

I am definitely enjoying the Mac experience after seeing how well it integrates with my other apple devices. It was pricey but has been worth it so far.

 

[shywizard]

XP-360, now that you mention it... The white line only appears left or right of the active window on the desktop.
It happens so fast it’s tough to tell. But I think your right.

 

[PieTunes]

XP-360, now that you mention it... The white line only appears left or right of the active window on the desktop.
It happens so fast it’s tough to tell. But I think your right.

This made me think of something. Might be hard to tell, but I wonder... could the flashing white line be on the same row of pixels where the mouse cursor is?

 

[shywizard]

This made me think of something. Might be hard to tell, but I wonder... could the flashing white line be on the same row of pixels where the mouse cursor is?

Or maybe it does cross the entire screen, but I lose the visual of the line because my background is dark and the windows are typically white or light. Hard to tell

 

[kkh]

I think... think... that I have seen it go across the Safari window. And I definitely saw it whilst in Logic.

Question: to make Apple aware of this -- in the most constructive way possible -- do we just individually call them? "Hey, I have this problem and I think others do, too." and they will recommend you get it serviced (however that works in this pandemic world)... or is there a better way?

 

[Whiteman007]

Whiteman007, if you launch FaceTime window, does the top left corner fizzle?

i dont tink so but i'm not sure what u mean

 

[shywizard]

Open Face Time. Look at the top left corner of the window. Does it flicker as you resize the window size or move the window around??

 

[Whiteman007]

Open Face Time. Look at the top left corner of the window. Does it flicker as you resize the window size or move the window around??

does the theme matter?

i jsut checked resizing and moving it around it looks normal

 

[shywizard]

What do you mean by theme?

 

[lukasz74nj]

Do we know if this is a software issue or worse - some hardware problem? I'm thinking about cancelling my order since there are so many reports.

 

[CheesePuff]

Do we know if this is a software issue or worse - some hardware problem? I'm thinking about cancelling my order since there are so many reports.

No one can know for sure but almost 100% certainly is a driver or macOS issue that can be addressed in a future update

 

[Whiteman007]

What do you mean by theme?

Dark mode or light for the OS

 

[joevt]

Everything looks about right in that whole AGDCDiagnose dump. Here's the HBR2 stuff.

Port Capabilities:
* 1: AUX, DDC, MST
* 2: AUX, DDC, MST
3: AUX, DDC, MST
4: AUX, DDC, MST
Connections:
* 1: [DP 1.2 4 x HBR2] Status: [4 x HBR2 7777] caps [features 0x103141f, p_encoding 0xd] Sink OUI:000-016-250 MN27i1 [077-078-050-055-105-049] HW Version: 16 FW Version: 1.1
* 2: [DP 1.2 4 x HBR2] Status: [4 x HBR2 7777] caps [features 0x101141b, p_encoding 0xd] Sink OUI:000-016-250 MN27i1 [077-078-050-055-105-049] HW Version: 16 FW Version: 1.1

As expected, two 4 lane DisplayPort 1.2 connections to the 5K display like most 5K displays that support 10 bpc. I don't know enough about DisplayPort to know if the DPCD registers listed in the AGDCDiagnose output show DisplayPort errors or not. It seems this is not a DisplayPort connection problem and more like a GPU/driver problem. The square window corners is definitely a driver problem.

 

[xp-360]

I think... think... that I have seen it go across the Safari window. And I definitely saw it whilst in Logic.

Question: to make Apple aware of this -- in the most constructive way possible -- do we just individually call them? "Hey, I have this problem and I think others do, too." and they will recommend you get it serviced (however that works in this pandemic world)... or is there a better way?

First, I would recommend everyone in this thread experiencing an issue to take 1 minute and report it to apple as a "bug report" here : https://www.apple.com/feedback/imac.html

If you are happy to wait a month or two, they might already be aware of it and a software update will hopefully fix it.

If you are convinced a hardware replacement is in order, call them up and get them to sort it out.

 

[shywizard]

Dark mode or light for the OS

Whiteman007, you are on to something! The corner glitch happens regardless of my Appearance Theme. However, if I CHANGE the theme to either Light or Dark or Auto, the 'corner issue' immediately and only temporarily goes away. Interestingly, I find that if I keep the "General" System Preference window open in the background after changing the Appearance Theme, the corner glitch is less likely to immediately return. Upon closing the General System Preference window, the corner glitch always comes back (sometimes not immediately though).

I seem to be able to force the corner glitch to happen (most of the time) by minimizing the Face Time window to the dock by clicking the yellow dot, then open it back up OR I can quit Face Time and relaunch the software (I'm just using Face Time as the example because it's easy to see with the dark window).

Can anyone else confirm some of my findings as well?

 

[shywizard]

I was able to capture the white horizontal line in the initial setup screen

 

[torifile]

I've been on my computer all morning running 2 displays with a ton of apps going and I haven't noticed any white lines at all.

 

[kkh]

I've been on my computer all morning running 2 displays with a ton of apps going and I haven't noticed any white lines at all.

Two displays. Is this the fix? No lines. Any sharp corners?

 

[PieTunes]

I've been on my computer all morning running 2 displays with a ton of apps going and I haven't noticed any white lines at all.

Funny you mention that, I was about to post this morning that I used my iMac for about 4.5 hours straight last night after I got home, and with it being in the evening everything was in dark mode with a dark background. Flashing white lines would have been easily noticeable but I didn't see one at all. Who knows what's going on LOL

 

[torifile]

Two displays. Is this the fix? No lines. Any sharp corners?

None. Everything is perfectly normal.

 

[kkh]

None. Everything is perfectly normal.

I would plug in another screen if I had one. What happens if you're using the iMac screen only? Any diff?

 

[kkh]

Funny you mention that, I was about to post this morning that I used my iMac for about 4.5 hours straight last night after I got home, and with it being in the evening everything was in dark mode with a dark background. Flashing white lines would have been easily noticeable but I didn't see one at all. Who knows what's going on LOL

The white lines seems to be completely unrelated to any activity. Taxing the card does not seem to affect it. It's almost the opposite -- I've noticed the lines the most when I'm just reading something in Safari, for example... not even scrolling.

 

[torifile]

I would plug in another screen if I had one. What happens if you're using the iMac screen only? Any diff?

I don’t know. I’ll try later but right now I’m just reveling in having all that screen real estate after spending the past 5 months staring at zoom on my 13” screen.

 

[PieTunes]

The white lines seems to be completely unrelated to any activity. Taxing the card does not seem to affect it. It's almost the opposite -- I've noticed the lines the most when I'm just reading something in Safari, for example... not even scrolling.

Oh I wholeheartedly agree, I didn't mean that I was doing anything intensive for any duration last night, just meaning that I used the machine for over four hours to read, browse, shop, study, email, message. Nothing taxing. And no white flashing the whole time. Odd how before I would be doing the same basic things and I'd see the flash while reading an email, maybe an hour later it would happen again browsing Safari, then a couple minutes after it would happen again, etc. I just expected to see it again during 4+ hours of use, but nothing.

 

[kkh]

Oh I wholeheartedly agree, I didn't mean that I was doing anything intensive for any duration last night, just meaning that I used the machine for over four hours to read, browse, shop, study, email, message. Nothing taxing. And no white flashing the whole time. Odd how before I would be doing the same basic things and I'd see the flash while reading an email, maybe an hour later it would happen again browsing Safari, then a couple minutes after it would happen again, etc. I just expected to see it again during 4+ hours of use, but nothing.

Yep, same here: expected to see it more over a period of time... but it seems completely random. Sometimes I see several in a row and then nothing for a long time.

My current theory: it has to do with the alpha channel not being rendered correctly somehow. Hence we end up with 1) the sharp corners and 2) the white lines that seem to extend from the edges of the windows. What do we have there? Well, the rounded corners are clearly created with alpha as are the shadows. Do we get the white lines because the card freaks out when it can not render in the shadows or corner areas correctly?