iMac 2020, 5700XT - graphical glitch?

[jamesh123]

Im seeing the white line flickering with the 5700XT too but have attached an external montior for now. I get weird display "adjustments" where it goes from dull to bright every now and then too. What's interesting is if you check the VRAM in iStat Menus it will keep building until it reaches 100% without even doing any activity. It will reset itself on removing the external monitor or I think if the iMac sleeps. This can't be normal.

Whenever I play a game the fans are maxing all the time. Now this might happen anyway but if the graphics are contstantly maxed out then it can't help and could lead to increased fan use. I wonder if the VRAM buildup is related to the flickering? Any thoughts on this? I don't know what the expected behaviour is here though.

I have spoken to Apple many times and they always say they haven't heard of the issue. As soon as I paste this forum thread in they say they are aware and engineers are looking at an issue affecting a small number of iMacs. My concern is they are viewing it as a small % of the iMacs but it actually affects all iMacs with the 5700XT (which is probably relatively small as a % of the total). Unless they understand this they won't be taking it seriously so please keep reporting the issue!

 

[torifile]

I'm in the same boat. Thanks to everybody for sharing here. To those who think this is some really nit-picky behavior of people who have no real work to do: I have to disappoint you.

I do need to get real work done - which is the core of the problem. I now have to send the iMac back and will have a few days without a large monitor. This is costing me real money!
What is more troubling to me is that I do not really know what to do next. I have a 2018 13" MBP as a backup that I would love to connect to a high ppi 32" monitor. Problem is - the only option is the XDR (can no longer work with text non-retina), which does not work with the 2018 model.
No, I do not want a convoluted eGPU setup. I want simplicity with high ram, CPU and a decent GPU.

Again, I am not nit-picky. But getting a "white flash" every now and then is just not acceptable. It distracts me. In particular given the 27" were a compromise in the first place.

Would love to hear from our little self-help group here what those who send back do next - and ideally get recommendations for myself out of it.

If you need a new computer and absolutely must have no glitches, you've got 2 choices - get one without the 5700xt or attach a secondary display to it. I've been running a secondary display for weeks and I haven't had the glitch once.

 

[theDanielJLewis]

I had heard about this glitch before my iMac arrived, so I recognized it immediately when it happened during my initial setup! I wasn't even fully into macOS, yet! I was still configuring my network, account, and such.

I think the line flickers every couple or few minutes.

 

[AZREOSpecialist]

Im seeing the white line flickering with the 5700XT too but have attached an external montior for now. I get weird display "adjustments" where it goes from dull to bright every now and then too. What's interesting is if you check the VRAM in iStat Menus it will keep building until it reaches 100% without even doing any activity. It will reset itself on removing the external monitor or I think if the iMac sleeps. This can't be normal.

Whenever I play a game the fans are maxing all the time. Now this might happen anyway but if the graphics are contstantly maxed out then it can't help and could lead to increased fan use. I wonder if the VRAM buildup is related to the flickering? Any thoughts on this? I don't know what the expected behaviour is here though.

I have spoken to Apple many times and they always say they haven't heard of the issue. As soon as I paste this forum thread in they say they are aware and engineers are looking at an issue affecting a small number of iMacs. My concern is they are viewing it as a small % of the iMacs but it actually affects all iMacs with the 5700XT (which is probably relatively small as a % of the total). Unless they understand this they won't be taking it seriously so please keep reporting the issue!

I googled "5700xt vram issue" and got lots of hits on the PC side. Some sound a lot like what you're saying, i.e., high ram usage while doing basically nothing.

 

[ADGrant]

All the reports I've seen—here and in the Apple forums—had the 5700XT.

People with the 5700 have reported the corner glitch on this thread. The poll shows reports of the flicker with other GPUs too (might be in error though).
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Trying to figure out a safest option to pick for my new order - is the corner glitch happening only with 16GB 5700XT's or also on 5500XT & 5700 8GB?

iMac Pro with a Vega GPU.

 

[ADGrant]

Im seeing the white line flickering with the 5700XT too but have attached an external montior for now. I get weird display "adjustments" where it goes from dull to bright every now and then too. What's interesting is if you check the VRAM in iStat Menus it will keep building until it reaches 100% without even doing any activity. It will reset itself on removing the external monitor or I think if the iMac sleeps. This can't be normal.

Whenever I play a game the fans are maxing all the time. Now this might happen anyway but if the graphics are contstantly maxed out then it can't help and could lead to increased fan use. I wonder if the VRAM buildup is related to the flickering? Any thoughts on this? I don't know what the expected behaviour is here though.

I have spoken to Apple many times and they always say they haven't heard of the issue. As soon as I paste this forum thread in they say they are aware and engineers are looking at an issue affecting a small number of iMacs. My concern is they are viewing it as a small % of the iMacs but it actually affects all iMacs with the 5700XT (which is probably relatively small as a % of the total). Unless they understand this they won't be taking it seriously so please keep reporting the issue!

I see the VRAM issue too. I am currently at 100%. I do not have an external monitor attached.

 

[ADGrant]

I googled "5700xt vram issue" and got lots of hits on the PC side. Some sound a lot like what you're saying, i.e., high ram usage while doing basically nothing.

Sounds like this might be an issue with low level drivers.

 

[ADGrant]

Weird your mileage may weary,

If this is a software glitch why don't I have to same as you? I just have to sharp corner on Face Time that I've seen

Because software bugs sometimes occur at random, particularly if it is something like a race condition on a shared memory location.

 

[sunman42]

This is so frustrating...I'm just waiting on Apple to fix this issue everyday, so I can order the damn thing.

It sounds like it would a really good idea to let Apple know that.

 

[ADGrant]

It sounds like it would a really good idea to let Apple know that.

Or maybe just buy something else like an iMac Pro. This problem is unlikely to be fixed in the next few weeks.

 

[AZREOSpecialist]

This is not something that should keep anyone from buying an iMac20,2. There is an easy workaround mentioned multiple times in this thread for the white line and the corner thing is not even something that's visible. I didn't notice it until I came here and read about it, and even then I had to put my face up close to the screen to be able to see this 10x10 pixel square. It's not a thing, really. The design of the icons in Big Sur is far more troubling.

 

[shywizard]

Apple seeds seventh macOS Big Sur developer beta for testing. Let’s pray and hope!

 

[AZREOSpecialist]

Apple seeds seventh macOS Big Sur developer beta for testing. Let’s pray and hope!

Can the AMD kexts simply be copied from Big Sur to Catalina?

 

[kkh]

This is not something that should keep anyone from buying an iMac20,2. There is an easy workaround mentioned multiple times in this thread for the white line and the corner thing is not even something that's visible. I didn't notice it until I came here and read about it, and even then I had to put my face up close to the screen to be able to see this 10x10 pixel square. It's not a thing, really. The design of the icons in Big Sur is far more troubling.

Keep saying "it's not a thing, really". Maybe you will convince yourself that it is not? Like I stated before, if the corners of the windows (a fairly basic thing, tbh) are not rendering properly, what potentially bigger thing is that an indicator of? And will it get better or worse over time as macOS software and the related drivers mutate? And what hardware bug is that potentially exposing or pointing at? We simply do not know. And it looks ugly and glitchy as all hell.

And yes, I agree, what in the world is going on with the Big Sur icons!?

 

[kkh]

Can the AMD kexts simply be copied from Big Sur to Catalina?

One of us will have to try if/when we get no messed up corners or white lines in Big Sur.

 

[kkh]

I googled "5700xt vram issue" and got lots of hits on the PC side. Some sound a lot like what you're saying, i.e., high ram usage while doing basically nothing.

High VRAM usage is typically not something you need to worry about. It is normally by design. Allocating and freeing up memory takes time. Afaik, most GPUs utilize all of the available VRAM to maintain performance. Otherwise it is sort of wasted.

 

[torifile]

High VRAM usage is typically not something you need to worry about. It is normally by design. Allocating and freeing up memory takes time. Afaik, most GPUs utilize all of the available VRAM to maintain performance. Otherwise it is sort of wasted.

Exactly. Free RAM is wasted RAM.

 

[haddy]

This is not something that should keep anyone from buying an iMac20,2. There is an easy workaround mentioned multiple times in this thread for the white line and the corner thing is not even something that's visible. I didn't notice it until I came here and read about it, and even then I had to put my face up close to the screen to be able to see this 10x10 pixel square. It's not a thing, really. The design of the icons in Big Sur is far more troubling.

Well actually yes, for me anyway, If this is not sorted soon I'll spend $NZ10,000 on a iMac Pro!!

 

[CE3]

High VRAM usage is typically not something you need to worry about. It is normally by design. Allocating and freeing up memory takes time. Afaik, most GPUs utilize all of the available VRAM to maintain performance. Otherwise it is sort of wasted.

I noticed iStat was showing GPU usage at 100% while reading @jamesh123's post. I had 3 Safari tabs, Calendar, and Apple TV opened. I closed everything and VRAM usage stayed at 100% until I restarted the iMac. That doesn't seem normal to me, but I've never paid attention before.

Looking at my VRAM history over the past 7 days I'm seeing lots of usage peaks at 75%, with the last two days being close to 100%. I've not been doing anything that would require it to be this high.

 

[ADGrant]

Well actually yes, for me anyway, If this is not sorted soon I'll spend $NZ10,000 on a iMac Pro!!

How soon is soon for you?

 

[dspdoc]

DAY 45 WITH NO FIXES

 

[jamesh123]

To follow up on the VRAM build up I was seeing and others have confirmed. Like @kkh says it's not necessarily an issue it seems.

This is a similar issue:
https://www.reddit.com/r/hackintosh/comments/hdeaii
And in this thread it's explained why it happens:
https://www.reddit.com/r/hackintosh/comments/cji42h

 

[Astero]

"it's not necessarily an issue it seems"
Does fan speed up?

 

[MikeeVideo]

I got my 2020 iMac Thursday night. It's as fast as expected and gorgeous. Last night I thought I saw, out of the corner of my eye, a horizontal white line flash mid-way up the screen. It was really fleeting and I thought I was just seeing things. This morning, I saw the same thing. The computer isn't running hot or anything. iStat Menus has all the cores untaxed. I recall having this same problem with my MBP 13" (2019) with an earlier version of macOS (I can't remember if it was a late Mojave build or an early Catalina) and it was cleared up with a software update.

Anyone else noticing flashes of graphical issues?

iMac 20,2
3.6 ghz, 10 core
5700XT
32 gig OWC RAM (OEM RAM has been removed)
2TB SSD

Hi(Bonjour)

Look at this video to see my unhappy unboxing...

On Youtube...

Michel B.

 

[jasonefmonk]

Just want to say that within days of releasing iOS 14 and iPadOS 14 with a default-apps bug, Apple has issued a statement promising a fix in a future software update.

There are many millions of people using iOS and iPadOS. That number will rise quickly. There are maybe only thousands of us with the 5700 XT. If you experience any issue, corners or flickering, you should contact Apple Support for all our sakes.