iMac 27 inch 2020 - Screen Glitch (Random Lines Appear on Screen)

How I understand it, the fan noise difference between i7 vs i9 and 5700XT vs lower gpu, would be mainly (only?) in the way how often, how fast and for how long they ramp up the fans. The diff would be mostly noticeable in high temperatures, right?

What I'm saying is, that it's not the loudness of the fan that bothers me, but the "shape of the sound". Ie having a lower temperature setup won't resolve my personal problem with the sound of the fan while in idle state. My CPU is now 43C, ambient 36C and fan RPM 1198, nothing, literally nothing's running and I can hear the fan anyway.

Happy to be proven wrong of course. But you're right, we'd need a measured acoustic test, otherwise all these are only subjective interpretations and guesses, including mine.

It is the point when you state something that's patently absurd.... dude.

If meant to say you were simply comparing the two similar machines under like circumstances, you should have said it. are they similar? Does you 2019 machine have a high-end graphics card (for its time)?

FWIW, which may be nothing, your ambient temperature is a lot higher than the airco'ed labs in which Apple tested the noise levels. Most US workplaces are kept at 25 C or cooler. Even the more environmentally conscience set their thermostats at ~ 26 or 27 C.

But both your evidence and others here suggest that the sound spectrum (power as a function of frequency) is different in the 2020 model from previous ones, whether because of the absence of the HDD mounting hardware or some other reason.

Hi, I am reporting back that the line is back. It was gone for a solid week. It seems like resetting the SMC and NVRAM is only a temporary fix.

Also, I think Apple Insider wrote my way into one of their articles, so if they see this update they can declare this way is of no use.

I am too deep into customizing my softwares now to return it and wait another 2 weeks for it to come, so I am begging apple to come up with a fix.

That's very interesting! According to Apple's technical specification page the sound level of the iMac 2020 at idle is 13 dB. According to comparable sound level charts, this is equivalent to normal breathing (10 dB) and yet more quieter than whispering from 5 feet away (20 dB). My general reaction is that I'd be a little disappointed if I heard the fans when doing non-intensive tasks such as emailing and web browsing. My MacBook Pro Retina 13" Early 2015 is silent doing those tasks! But at 13 dB, I'd be reasonably happy with that - as I work in a quiet office and don't like a lot of background noise. For those of you that own the iMac 2020 can you please confirm... is "equivalent to normal breathing" a realistic comparable sound level that is being experienced?

I'm wondering too if this dB rating takes into account any contributing noise from the Radeon Pro graphics options. Surely the 5700XT is louder than the 5700 for instance!?

Also, I've read some owners reporting that the iMac 2019 is quieter than the iMac 2020 at idle, but yet it's rated slightly higher at 16 dB at idle on Apple's tech spec page. I would think removing the mechanical drive and leaving a lot of empty space (presumably creating better cooling) would cause the iMac 2020 to be quieter?

For those of you that own the iMac 2020 can you please confirm... is "equivalent to normal breathing" a realistic comparable sound level that is being experienced?

The sound level of breathing with open mouth I'd say, yea. That's how my top spec iMac 2020 sounds when idle. (As opposed to top spec iMac 2019 which was dead silent when idle.)

I would think removing the mechanical drive and leaving a lot of empty space (presumably creating better cooling) would cause the iMac 2020 to be quieter?

Leaving a lot of empty space just makes it sound more like as if coming from a tin can. (As opposed to the 2019 model, which sounds more dampened down.)

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Overall, the fan noise while idle is not that bad for me personally, since I'm not recording pro audio and am on headphones most of the time anyway, so can't hear it.

I'm more bothered by the graphical glitches, GPU crashes in games and BT keyboard lag in certain apps :/

Same issue on my new iMac 27 2020. Has anyone been able to resolve this issue with Apple support? Would love to learn how Apple can resolve this technical/software/hardware issue for so many consumers/users. If the Apple Stores were open for business, I would return my iMac system for a new one. Would love to hear how others are dealing with this issue good or bad. Thank you

"Surely the 5700XT is louder than the 5700 for instance!?"

Unlike in the 2019 Mac Pro and PCs with PCIe slots, the graphics here is just a chip, apparently soldered to the motherboard. (See iFixit's less than elaborate teardown.) There's only one (fairly large) fan in the iMac 27, and any internal noise, now that HDDs are a thing of the past, is noise from that fan.

Presumably, yes, the 5700 XT (40 compute units) generates more heat than the 5700 (36 units), and thus requires more cooling.

Thanks for sharing. I returned my unit and will not order a new one before someone can confirm that

the issue(s) have been addressed - preferable via a software update. I still wonder if the white line flashes and my full system crashes are/were related.

Boy, this is so disappointing. I was getting close to ordering one of these, but I think I will wait a few months until they address this. It seems to be a widespread issue. For all that $$$ (and all the $$$$$$$$ that the company has available) this seems like a major fail.

I decided to cancel my order with the 5700XT as it seems even people getting them now have issues. I’m not a gamer and I decided to re-purchase with the 5700 regular which should be enough.

I also went from regular to nano glass, as,my desk is located,next to a window and I think this will cut down on glare and washout from the sun. Seems the jury is mixed in this glass. Some say it’s amazing others say it’s not worth it and some say it has viewing angle issues and makes text harder to read.

Is there any consensus as to if this is a hardware or software issue? It sounds like a software issue but with people being to,d to return their units for new ones... that sounds like a hardware issue. However it just may be standard to tell people that having issues.

any thoughts on what it is?

Ok, hmm, Civilization has a demo available only on Windows and not sure if by "skyline" is meant Cities:Skylines or Infinite Skyline. Neither of them have demos anyway though.

Went and downloaded the first f2p I could google and installed StarCraft II. There in settings couldn't even select my custom screen resolution, only the given OS defaults.

So I guess this SwitchResX workaround won't be any good for gaming, by the looks of it

Thanks for the effort nevertheless. I must wait for people to confirm when the thine line glitch has been fixed, then re-order my iMac and hope for the best. 128 GB third-party RAM just collecting dust in the drawer - very frustrating.

I've been waiting for a new iMac model for a long time. But I'm not going to pull the trigger on a new one until this issue has a resolution. I'd be ok if I was just assured that it is a software issue.

But I certainly don't want to deal with a hardware hassle with a brand new unit. Is there a place where Apple can have people like me voice their concerns? It would definitely help to define how much $$$ Apple is losing based on this issue and help to prioritize efforts to resolve it.

Besides having the line glitch randomly popping up across the screen, another thing I notice is that the fan is constantly on, even when idle. I work in a quiet space so its more noticeable. Is this normal? my previous iMac's were quite and only heard the fans when rendering videos in fcpx.