Graphical Glitches Plaguing Some 2020 iMac Owners With Radeon Pro 5700 XT GPU
Apple in August refreshed the 2020 iMac lineup with a new 27-inch model that's equipped with 10th-generation Intel processors, more RAM, more SSD settings, and faster AMD GPUs.
Unfortunately, some new Mac owners have been running into problems with their machines and have been reporting ongoing glitching with the graphics. There's a 57-page thread on the MacRumors forums filled with complaints dating back to August, suggesting this is a problem that's been impacting iMac owners since the new Macs came out.
Based on a poll, a good number of iMac owners who have the higher-end 5700XT GPU are seeing a white horizontal line flicker across the display on occasion, but the problem does not seem to impact all users.
MacRumors reader
torifile describes the issue:
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.
The white line described by those affected appears to flash across the screen at random intervals throughout the day, and there are some other seemingly related graphical issues that iMac owners have run into. Some users have reported being able to remedy the problem by choosing a scaled resolution other than the default, but that's not an ideal longterm solution.
It's not clear if the issue that iMac owners are experiencing is hardware or software based, but Apple has not yet implemented a fix for the problem.
Popular Stories
Apple's Worldwide Developers Conference (WWDC) starts today with the traditional keynote kicking things off at 10:00 a.m. Pacific Time. MacRumors is on hand for the event and we'll be sharing details and our thoughts throughout the day.
We're expecting to see a number of software-related announcements led by a design revamp across Apple's platforms that will also see the numbering of all of...
At today's WWDC 2025 keynote event, Apple unveiled a new design that will inform the next decade of iOS, iPadOS, and macOS development, so needless to say, it was a busy day. Apple also unveiled a ton of new features for the iPhone, an overhauled Spotlight interface for the Mac, and a ton of updates that make the iPad more like a Mac than ever before.
Subscribe to the MacRumors YouTube channel ...
Apple today announced a complete redesign of all of its major software platforms called "Liquid Glass."
Announced simultaneously for iOS, iPadOS, macOS, watchOS, tvOS, visionOS, and CarPlay, Liquid Glass forms a new universal design language for the first time. At its WWDC 2025 keynote address, Apple's software chief Craig Federighi said "Apple Silicon has become dramatically more powerful...
Apple today announced that iPadOS 26 will be compatible with the iPad models listed below.
iPadOS 26 features a new Liquid Glass design, a menu bar, improved app windowing, and more.
iPadOS 26 supports the following iPad models:iPad Pro (M4)
iPad Pro 12.9-inch (3rd generation and later)
iPad Pro 11-inch (1st generation and later)
iPad Air (M2 and later)
iPad Air (3rd generation and...
In 2020, Apple added a digital car key feature to its Wallet app, allowing users to lock, unlock, and start a compatible vehicle with an iPhone or Apple Watch. The feature is currently offered by select automakers, including Audi, BMW, Hyundai, Kia, Genesis, Mercedes-Benz, Volvo, and a handful of others, and it is set to expand further.
During its WWDC 2025 keynote today, Apple said that 13...
Apple at WWDC announced iOS 26, introducing a comprehensive visual redesign built around its new "Liquid Glass" concept, alongside expanded Apple Intelligence capabilities, updates to core communication apps, and more.
Liquid Glass is a translucent material that reflects and refracts surroundings to create dynamic, responsive interface elements, according to Apple. The new design language...
