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 today seeded the release candidate version of iOS 18.5 to developers and public beta testers, giving us a look at the final version of the update that will be provided to the public next week.
With the release candidate, Apple provided release notes, so we have a more complete look at the new features that are included in the update, including those that weren't found during the beta...
If you owned a Siri-compatible device and had an accidental Siri activation between September 17, 2014 and December 31, 2024, you could be eligible for a payment from Apple as part of a class action lawsuit settlement.
Apple in January agreed to pay $95 million to settle a class action lawsuit involving Siri spying accusations, and a website to distribute the funds has now been set up and...
We've still got months to go before the new iPhone 17 models come out, but a combination of dummy models and leaks have given us some insight into what we can expect in terms of camera changes.
Apple is adding new camera features, and changing the design of the camera bump for some models. You might be skeptical of dummy models, but over the years, they've proven to be a highly accurate...
In its press release for the new Pride Band today, Apple said that iOS 18.5 is "upcoming," following more than a month of beta testing.
We expect the iOS 18.5 Release Candidate to be released this week, and this should be the final beta version, barring any last-minute bugs or changes. The software update should then be released to the general public next week.
iOS 18.5 is a relatively...
Apple plans to release its first foldable iPhone next year, according to several reporters and analysts who cover the company.
In his Power On newsletter today, Bloomberg's Mark Gurman said the foldable iPhone will offer two key advantages over other foldable smartphones.
First, he said the foldable iPhone will have a "nearly invisible" crease when unfolded. This means the device's...
The first iOS 19 beta is just one month away, and there are already many new features and changes that are expected with it.
Apple should seed the first iOS 19 beta to developers immediately following the WWDC 2025 keynote, which is scheduled for Monday, June 9. Following beta testing, the update should be released to the general public in September.
Below, we recap the key iOS 19 rumors...
Apple's upcoming foldable iPhone will feature a new type of display panel developed by Samsung that has never been used in a foldable product, claims a source with links to Apple's supply chain.
According to the account yeux1122 on the Korean Naver blog, the foldable iPhone will use a custom display process for which Apple will hold branding trademark rights, and that meets Apple's stringent ...
Despite being more than two years old, Apple's AirPods Pro 2 still dominate the premium wireless‑earbud space, thanks to a potent mix of top‑tier audio, class‑leading noise cancellation, and Apple's habit of delivering major new features through software updates. With AirPods Pro 3 widely expected to arrive in 2025, prospective buyers now face a familiar dilemma: snap up the proven...