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iMac 2020, 5700XT - graphical glitch?
- Thread starter torifile
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Both of my iMacs from China
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Both my iMacs are i9
Seems to be the common link is the 5700XT.
This thread has had both i7 and i9, made in China and Ireland variants. Common thing is always the 5700XT it seems.
Considering how quick the issue occurs (and therefore easily missed), many others may have it and not even realise.
Ok, so it can happen with either the left DisplayPort connection or the right DisplayPort connection.
What would be strange is if the line stretches across the middle of the screen (through 3 or 8 or 13 or 18) but in that case it could be a coincidence that a glitch happens at the same time to both halves of the screen.
Interesting. But the glitches don't extend from one side to the other, correct? It would be unexpected if they did or just a coincedence.
MacBook Pro 16" 5600m has iGPU that gets used when there is no external display connected so maybe you don't see the error on the internal screen because of that?
You can use gfxCardStatus to switch from iGPU to dGPU even when no external display is connected. Then you might see glitch on the internal screen? gfxCardStatus will show which GPU is currently being used.
Your external display is not a 5K display? So you might see a glitch cross the centre since only one connection is used for the entire screen.
Seems AMD Navi always had bad drivers in macOS (and Windows?) Maybe they'll get it right eventually. Maybe there's a firmware change required to fix voltage of something in the GPU...
Thats good, but I wouldn't call that an acceptable work around.
A lot of people with 27" 5K screen, won't run a second monitor. So this issue needs to be addressed. At the very least we need to ascertain if its hardware or software.
Has anyone noticed if it happens while in Bootcamp Windows?
Okay something truly odd is going on here.
Last night, 4+ hours of usage, no flashing white line. This morning I use it for a couple hours, nothing. I'm out all day and get home about 3 hours ago and have been using the iMac since, again no flashing white line. Then as I'm using my iMac and playing around, I wanted to see if the Aerial screen saver would look any different if I change to a scaled resolution.
I typically stick with the default, but decide to change it to More Space (3200x1800) and then this happens (forgive the horrible quality and lighting conditions):
I have True Tone off and have Night Shift enabled, which has been on since sundown. Upon changing the resolution, half the screen is still in Night Shift, the other half not. My display is having an identity crisis! It persists this way until I change the resolution back to Default, then back to More Space, and it's back to normal.
Unable to duplicate this random occurrence anymore no matter what resolution settings I pick, if I enable/disable True Tone and Night Shift, etc.
This may or may not be related to the flashing white line that seems to pop up for us 5700XT owners. Has anyone heard or seen this happen on any previous generation of 27" 5K iMacs?
Last night, 4+ hours of usage, no flashing white line. This morning I use it for a couple hours, nothing. I'm out all day and get home about 3 hours ago and have been using the iMac since, again no flashing white line. Then as I'm using my iMac and playing around, I wanted to see if the Aerial screen saver would look any different if I change to a scaled resolution.
I typically stick with the default, but decide to change it to More Space (3200x1800) and then this happens (forgive the horrible quality and lighting conditions):
I have True Tone off and have Night Shift enabled, which has been on since sundown. Upon changing the resolution, half the screen is still in Night Shift, the other half not. My display is having an identity crisis! It persists this way until I change the resolution back to Default, then back to More Space, and it's back to normal.
Unable to duplicate this random occurrence anymore no matter what resolution settings I pick, if I enable/disable True Tone and Night Shift, etc.
This may or may not be related to the flashing white line that seems to pop up for us 5700XT owners. Has anyone heard or seen this happen on any previous generation of 27" 5K iMacs?
Correct. I have never seen a line completely cross my screen. It's been left and right, randomly. In most cases in the lower half of the screen.
I still think that it has to do with alpha. Or maybe it has to do with clipping or layering of windows. Earlier today I said that maybe it has to do with the drop shadow. But, I have seen this happen in apps like Adobe InDesign today with no shadows going on. So, don't think it's the drop shadow.
1) For the rounded corners (mostly the top-left one), alpha is either on or off. Or I get random pixels suggesting alpha channel corruption.
2) The lines seem to extend into or out of whatever the current in-focus or clipped window or component is. Could be a Finder window edge, could be an app window edge, or could be the edge of an active canvas in one of the Adobe apps.
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Whoa! Okay. This is pretty crazy. So, something about the left and right ports being out of sync? Sheesh. I really do hope this is a software fix.
And I was browsing Safari just now, doing some window shopping, and there was a white line flash about 2 thirds of the way down the screen on the right side, over the background wallpaper and not inside any active or even background windows. I stared at that area and within a few seconds, a second white line flash happened again in the same place.
I couldn't immediately discern if it lined up with anything in particular, be it the horizontal/vertical position of the mouse cursor, or if you extended any imaginary lines from all borders of all windows. All I can say is they appeared in seemingly the exact same spot as in the video @shywizard posted yesterday morning. Ugh...
I couldn't immediately discern if it lined up with anything in particular, be it the horizontal/vertical position of the mouse cursor, or if you extended any imaginary lines from all borders of all windows. All I can say is they appeared in seemingly the exact same spot as in the video @shywizard posted yesterday morning. Ugh...
This seems like a different problem than the flashing white line.
More space ("Looks like" 3200x1800) is a scaled resolution of 6400x3600 which is downscaled by the GPU to two 2560x2880 signals. One question: does the glitch happen with scaled resolutions (resolutions that are not the same as the resolution of the display)? For the 5K iMac display, the native resolution is 5120x2880 or "Looks Like/HiDPI/retina" 2560x1440.
I think most people would be using "Looks Like" 2560x1440?
I always use the default/unscaled resolution (as you say, 2560x1440 I believe) and have only seen the flashing white line there, I’ve never used another resolution for any length of time really. I just switched to that More Space resolution temporarily so I can see if there were any differences in a screen saver I was toying with. When I switched the screen went half and half like that, so I went back to default, then went More Space again and it was normal.
I personally can’t say if the white line happens in any other resolution because I don’t use anything but the default. I’d have to switch and use it for awhile to see but my eyes aren’t what they used to be!
For those getting the flashing white line, are you using the default or a scaled resolution and if so what is it set to?
Well if it's the 5700XT I presume those who have bought their 2020 iMac with the 5500XT and 5700 cards do not have the "glitches"?*raises hand*
I’m always using default resolution on the iMac. Wish more people can screen record their white line happening. Apple will need to see this in action to analyze and fix. Still curious if the horizontal line is related to the glitchy corner.
That is an interesting question. Why would a software problem affect only the 5700XT and not the very similar 5700 or even the 5500s.
Really good news! I captured lighting in a bottle 3 times! Please note that it does overlap the active window (just by a little bit). Apple, it’s up to you now. Figure this out!
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Thats what's starting to concern me.
Doubt I will buy one until we at least know if its software or hardware fault.
Are you considering returning it within the 14 day return period? Or are you confident its software related?