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

This is just a wild guess, but I'm going to bet the presence of a 5700 XT is going to increase fan noise over the 13 dB in that first link for a 2020 model with a 3.8 GHz i7 and the 5500 XT. Even for viewing a Web page. Ditto for the 10-core i9, even if its base clock rate is 0.2 GHz lower than the i7's. By how much, we'll have to wait for someone with really good noise measurement equipment and a soundproofed lab to tell us.

lol im with you, i thought the exact same thing... I was tired when i was setting it up and thought maybe it was just me.. After setting it up i noticed the line glitch which was really just random at best.. But i would have a quick time screen recording going at the same time as an external camera recording the screen. The Screen Recording from Quick time showed a perfect screen everything time, while the external camera caught all the glitches..

I order the 10 core 5700XT 16 GB GPU 10GB Eithernet, 4TB SSD (8 GB Memory - not paying 2600$ (which is absurd...) for128 gb when i can get it cheaper elsewhere

But anyhow My replacement comes in on the 16th of September, if it still has the issue i may send it back for a refund at that point and then just wait to see what is causing the issue.

Hope the new unit is fine.

That's more than one could ask for. I only play "Civilization VI" myself (not an easy game to play out of the box), but I believe another user in this thread had the same problem with "Skyline" - I see both are available as a demo on Steam. I totally understand if that is too much of a hassle for you. :-)

I must admit - I'm not surprised. I bought my first iMac in 2006. It was repaired after 2 years replacing the logic boards I think they called it. After this is actually didn't last long before the graphics adapter stopped working again. This time I could not get a repair since it was more than 5 years old.

I bought a new one - don't recall when. The graphics adapter went dead after a few years on that one - 2-3 years. If you know the oven trick - I used that to repair it - twice. 3rd time wasn't a charm.

Replaced it with my current iMac which have serious image retention issues.

The quality is just way too bad and luckily I searched here and there before ordering a new one which is kinda due. It's just sad to see such a respected company time and time again presenting such poor quality computers.

Might not be that helpful but I just had to get this off my chest.

Here's what I captured on video, even before I had a chance to setup my " New" iMac. This line glitch continues to happen. This is my second unit that replaced my first one with the same issue.

https://youtu.be/x83_QzLlv9Y

I feel just like you. I’ve been waiting patiently for a new iMac as I’m using a very old windows machine now. I was so excited for this and now am disappointed.

I just went for the 5700 instead of the 5700XT as I am not a gamer anyway. I wasn’t about to buy something that May or may not have a hardware issue.

cant wait for it to show up. Maybe you want to also consider stepping down to the middle graphics card.

I really hope it’s not making constant fan noise as well.

I am curious to find out what the process of returning the iMac 2020 considering non of the Apple stores is open due to COVID? I received my system three weeks ago, and the white horizontal lines are increasing & moving to different parts of the right screen. My iMac 27 is fully loaded and was a significant financial investment for me. Really disappointed that Apple is not owning this problem and getting in front of it.

I'm so confused... some people are so disappointed with the fan noise, even to the point of returning it for that reason, and yet others are also saying "it's really quiet" and can "hardly hear it at all!". I haven't ordered my iMac 2020 yet, but I'm just not sure what to make of it!?

I'm not experiencing this at all on my end with a very specific setup. Perhaps your graphics card became slightly dislodged during the shipping process? I have a similar setup to you, but absolutely no issues at this point.

There is no graphics "card" in the 2020 iMac 27-inch. There is a soldered-on chip, which is cooled by the same cold finger (copper pipe) and fan as the CPU.

Could you please confirm that you have the same configuration as appears to the one suffering from the screen glitch and possible intensive graphic crash issues, namely the 5700 XT graphic option? Also, which CPU option did you get?

Thanks.

Thanks!

I'm having a hard time envisioning how the chip, held down by a screwed- or riveted-on brace, inside a durable aluminum body, shipped in dense styrofoam (or whatever the CO_2-friendly replacement is called), in a sturdy corrugated cardboard box inside of another cardboard box, is liable to be damaged. For that to happen, you'd have to see the entrance and exit holes made by the 20 mm round. ;-)

Frankly, it's more likely there's a bad batch of chips, as there apparently was with the 2011 27 high-end graphics option, as michaeloupatrick says, a software issue. There could also, I suppose, be a graphics memory issue, since presumably the higher (full) resolution gets into higher graphics option memory sooner.

Just got my replacement iMac from Apple yesterday and it too has the same glitch issue (AGAIN)... I have the nano textured 27", 10 core i9, 4TB SSD, 128GB Memory (OMC's not Apple - too expensive and ripoff), 10gb Ethernet, and 5700 XT 16GBN. The first day was no glitches, then the second day (today) glitch's every 10 minutes.. I naturally tried the resolution changes and so far that seems to address the issue, but also heard that a secondary display also stops it. You can add some custom resolutions which also seems to work, but i was looking at getting a secondary 4k display anyhow so i opted to order one online from LG.

I can confirm the resolution change and/or dual display corrected my issues from what i can tell so far... (if that changes i will post an update), but so far so good.

The reset of the NVRAM and SMC work, but only temporarily (Sometimes not at all).

Yep! This has started happening to me now after only a few days of use! Oddly enough, it started happening while I was listening to YouTube in the background and working on some writing in Pages. I thought I noticed it while playing DOTA 2 on Steam yesterday, but I brushed it off because I was pretty engaged in the game. However, it's much more obvious when I'm just working on a Pages document.

Can confirm I have the AMD Radeon Pro 5700 XT 16 GB, the 10-core configuration, and 64gb of RAM.

Well After getting my replacement iMac.. I am running into the same issue but now have greater issues...

It locks up (beachball icon, then clock freezes - after a few seconds it reboots and i get a black screen with a message stating "Your computer restarted because of a problem..."

It has done this 4 times today resulting in a substantial loss of work, I cannot use this for school or work..

At this point the best options is to send it back. This means that 2 new iMacs (First one, and then the replacement) both have issues, but this second one in my opinion is worse, so I am now opting for a refund.

There is clearly some issues with the 27" 2020 iMac with the 5700XT Card... I have the 16 gb model with 128gb

It started with Glitches, Then True Tone refresh issues, Beachball icon and intermittent lockups and now unexpected reboots.

I personally don't want to know what's next... This think is as stable as mentos and coke...

Hoping they figure it out soon so I can order one that works, it glad to hear the 5700 is fine.. so far it seems to be just isolated to the 5700xt from what I been reading..

just dropped mine off at FedEx today for the refund