iMac 2020, 5700XT - graphical glitch?

[Mike Fisher]

Remember reading that the glitch has to do with the refresh rates. On both PC and Mac. Don’t think it’s an OS issue.

 

[AndyMacAndMic]

Remember reading that the glitch has to do with the refresh rates. On both PC and Mac. Don’t think it’s an OS issue.

According to most people in this forum the white line glitch does not manifest itself in Windows. So it seems an OS driver issue.

 

[CL14715]

According to most people in this forum the white line glitch does not manifest itself in Windows. So it seems an OS driver issue.

It's also said to not occur while under different scaled resolution. Trying that out now.

 

[AndyMacAndMic]

It's also said to not occur while under different scaled resolution. Trying that out now.

Yes. As far as I know it only happens in MacOS in default resolution and with no extra monitor attached.

 

[MikeeVideo]

Remember reading that the glitch has to do with the refresh rates. On both PC and Mac. Don’t think it’s an OS issue.

Not refresh rate, but resolution.

 

[DavePorter33765]

I have similarly tested my 2020 fully loaded imac with ps, bridge, lr, nimbers, pages, etc. running without problems of any kind.

I’m happy to hear that you are not experiencing the graphics issues either. Hopefully a solution will come soon for those that are.

 

[sunman42]

I certainly jinxed myself here, it’s getting catastrophic at this point. My new order arrived and was thoroughly beat by UPS in transit:

View attachment 957814

Open, re-“sealed”, wet through to interior, holes through to interior, sand and small stones throughout. But hey, it turned on.

I have also confirmed and recorded the screen tearing/white line glitch. I voted in the poll. It occurred during setup assistant. I honestly haven’t looked at the computer since but I’ll look for the corner render issue when I have the heart.

Does UPS charge for dragging the box through the surf, or is it included in the purchase price?

 

[PBG4 Dude]

Does UPS charge for dragging the box through the surf, or is it included in the purchase price?

It’s a special service they provide when they see the package is shipped from “Fragile”.

 

[David Y.]

Been using my new iMac for a week, been seeing the white line glitches about a dozen times per day, finally called up Apple and they want me to bring the computer in and let the technicians take a look... which I doubt they’ll find anything. Debating if I should just return the computer and buy it again when this issue is resolved...

other than this glitch issue, I’m really lovin this machine though. Came from a 15” MacBook Pro with a broken graphic card.

 

[CL14715]

Been using my new iMac for a week, been seeing the white line glitches about a dozen times per day, finally called up Apple and they want me to bring the computer in and let the technicians take a look... which I doubt they’ll find anything. Debating if I should just return the computer and buy it again when this issue is resolved...

other than this glitch issue, I’m really lovin this machine though. Came from a 15” MacBook Pro with a broken graphic card.

It's no doubt an amazing machine. I switched resolution and haven't seen the issue. Although I like the standard resolution more, I can tolerate it for now. Otherwise I'll end up downgrading and be unhappy I have the 5700.

 

[rkuo]

I wonder if you folks can reproduce the glitch while something GPU intensive is running in the background? It sounds suspiciously similar to some voltage/frequency curve glitches I’ve seen in the past.

 

[CL14715]

I wonder if you folks can reproduce the glitch while something GPU intensive is running in the background? It sounds suspiciously similar to some voltage/frequency curve glitches I’ve seen in the past.

I’ve watched istat like a hawk when it occurs and there’s no fluctuations of any sort.

 

[NLLV]

I thought I would post this, found someone on the official apple discussion board with the same problem, much different computer though:


Hi guys, I noticed the same lines glitch last night while watching Apple TV. I've had my 2019 Imac , 3.7 Ghz i5 , 8GB RAM , Radeon Pro 580X 8GB for two months now and this is the first time I've experienced this.

I updated macOS Catalina 10.15.6 about a week ago.

Today while watching YouTube the glitch started again.

Need some advice please on what to do next.

Thanks

iMac 27 inch 2020 - Screen Glitch (Random… - Apple Community

discussions.apple.com

This makes me lean toward this being a software issue. Anyone else?

 

[rkuo]

I’ve watched istat like a hawk when it occurs and there’s no fluctuations of any sort.

Istat wouldn’t necessarily catch these kinds of fluctuations.

 

[filmak]

I have the 5700

The XT one?

 

[CL14715]

The XT one?

I have the 5700xt

 

[Sheza]

you haven't written to any heatsink vendor, I can tell

I guess even when heatsinks vendors tell you, they will still being "idiot, non intelligent people" as AZREOSpecialist says, because maybe they do not speak perfect english

doesn't matter if they speak 3 languages, and english is not official / not an spoken language in their countries

doesn't matter if they have degrees on Informatics AZREOSpecialist is the only one who knows here

Dude.... I have temp sensors checking my 2020 iMac and I’m literally telling you, factually, that the GPU stays much cooler than the CPU in this Mac that I own and you seem not to!

 

[dspdoc]

DAY 51 WITH NO FIXES...

Maybe not ?

 

[wumpalumpa]

Dude.... I have temp sensors checking my 2020 iMac and I’m literally telling you, factually, that the GPU stays much cooler than the CPU in this Mac that I own and you seem not to!

I do not want to offend anyone Sheza, thermal sensors could had been tweaked

I insist, those are desktop chipsets. Any heatsink vendor would tell you it is crazy to place those in a non proper dissipated case as it is iMac case.

I'm using Mac myself, not iMac 2020 you are right, and is a legit Apple product what I have at home.

 

[Sheza]

I do not want to offend anyone Sheza, thermal sensors could had been tweaked

I insist, those are desktop chipsets. Any heatsink vendor would tell you it is crazy to place those in a non proper dissipated case as it is iMac case.

I'm using Mac myself, not iMac 2020 you are right, and is a legit Apple product what I have at home.

I completely understand the concepts you are using here. I have owned a desktop PC with a Noctua NH D-14 CPU cooler. Putting a desktop class chip in a chassis with a single blower is going to cause heat problems.

That’s why the chips run hotter and throttle more quickly than in a beefy desktop machine.

But I think you’re straying into conspiracy theory territory if you are suggesting that Apple tweaks temperature sensors to make them appear lower. I have seen temperatures for the CPU get into the high 90s. If you’re saying the sensors are tweaked then I should have a CPU that went beyond its T-Junction and it would be melted inside by now.

And, if we take your logic, it doesn’t even work. The line glitch can happen when doing the most idle of things, when the system is not being taxed and there is not a lot of heat being generated by the GPU.

 

[wumpalumpa]

I completely understand the concepts you are using here. I have owned a desktop PC with a Noctua NH D-14 CPU cooler. Putting a desktop class chip in a chassis with a single blower is going to cause heat problems.

That’s why the chips run hotter and throttle more quickly than in a beefy desktop machine.

But I think you’re straying into conspiracy theory territory if you are suggesting that Apple tweaks temperature sensors to make them appear lower. I have seen temperatures for the CPU get into the high 90s. If you’re saying the sensors are tweaked then I should have a CPU that went beyond its T-Junction and it would be melted inside by now.

And, if we take your logic, it doesn’t even work. The line glitch can happen when doing the most idle of things, when the system is not being taxed and there is not a lot of heat being generated by the GPU.

Following your answer

Getting Noctua as example (you choosed what is probably best CPU fan brand in the market)

Minimum for this chipset i7 10700kf would be to use a Noctua NH-l9x65

That's why is just unbelievable what apple is doing, using an small Heatsink + Small fan to dissipate the heat of both chipsets i7 10700kf + 5700XT

for me the problem is more than clear

nd, if we take your logic, it doesn’t even work. The line glitch can happen when doing the most idle of things

I do believe even if the chipsets are not doing any special tasks, those could overheat, due the fact of using a single dissipator for both chipsets.

 

[PBG4 Dude]

Dude.... I have temp sensors checking my 2020 iMac and I’m literally telling you, factually, that the GPU stays much cooler than the CPU in this Mac that I own and you seem not to!

I concur. Running Blender on GPU in Windows doesn’t ramp up the fans anything like rendering the same file as 16 threads on the CPU. It isn’t even a contest.

As an added bonus, the GPU finished in 1/3 of the time as the CPU. I’d consider lower heat generation and faster completion times a win win.

 

[MikeeVideo]

Following your answer

Getting Noctua as example (you choosed what is probably best CPU fan brand in the market)

Minimum for this chipset i7 10700kf would be to use a Noctua NH-l9x65

That's why is just unbelievable what apple is doing, using an small Heatsink + Small fan to dissipate the heat of both chipsets i7 10700kf + 5700XT

for me the problem is more than clear



I do believe even if the chipsets are not doing any special tasks, those could overheat, due the fact of using a single dissipator for both chipsets.

And how to explain that the line is showing even on startup, when the computer and chipset are cold? An not when running windows with parallels when the computer is hot?

 

[wumpalumpa]

I concur. Running Blender on GPU in Windows doesn’t ramp up the fans anything like rendering the same file as 16 threads on the CPU. It isn’t even a contest.

As an added bonus, the GPU finished in 1/3 of the time as the CPU. I’d consider lower heat generation and faster completion times a win win.

Because both chipsets are interconnected trough heatpipes "fact", one chipset can heat the other. Big problem itself.

About not hearing the fans ?‍♂️ . Taking in consideration they are in the wrong path using desktop chipsets in this small case, they could have set a fan RPM limitation to do not produce to much noise "just because is not nice to hear a fan".

I do not know, but the architecture of those iMacs is not a good one, that I can sincerely tell.

I do not know who they have in charge of validating the new hardware, but they made a big mistake.
They cannot lunch something like that pretending the chipsets are gonna work in those conditions, without prior extensive testing, because what they are doing to put chipsets under those conditions is something no one in the market is doing.

They are just not following at all vendors recommendations, sure Intel and/or AMD wouldn't agree to set those chipsets in that case.

** I'm writing those lines under MacOS

 

[wumpalumpa]

And how to explain that the line is showing even on startup, when the computer and chipset are cold? An not when running windows with parallels when the computer is hot?

As soon as you turn on the computer the chipsets get some heat, again, the heatsink iMac is using is more than not enough to hold the heat of those chipsets.

Maybe they replaced humans for monkeys in their research labs to go higher on benefits, I do not know.