Pixel Discoloration when using dedicated GPU (MBP 16")

[mtoddy]

I'm wondering if anyone else has noticed that while on dark backgrounds, finer white details (such as white text and the cursor's white edges) are discolored. Some distinct examples:

• As I move my cursor slowly, pixel-by-pixel, I can actually make the leftmost column of pixels of the white cursor border seem to disappear
• The blinking cursor during text input (again, white on black) appears to be bluish-green, depending on where the cursor is at the moment

This only happens while the dedicated GPU is active. It is as if the GPU is unable to scale properly for the resolution of the screen. This never happens with the integrated graphics. The thinner the white line, the worse the problem is.

Here are some examples of a blinking cursor that should be pure white but has a bluish-green tint:

Here is an example of where the cursor is discolored on the very left, but then looks normal if I move it a few pixels to the left:

In some apps, such as Microsoft Teams, all the text looks discolored because the font used has a lighter weight.

Again, all of this goes away if I am not using dedicated GPU. And taking a screenshot with dedicated GPU does not yield a snapshot that includes discoloration, so macOS doesn't "think" it's rendering anything but pure whiteness.

Before I go try to get this repaired or replaced, I'm curious to know if others have the same issue with white details on dark backgrounds like this.

Thanks!

 

[jerryk]

There are other thread on this already.

 

[mtoddy]

I'm on this site daily and haven't seen a single mention of this particular issue. Where is this issue being described? (Or how is it being referred to, or what are people calling it?)

 

[mtoddy]

To be clear, @jerryk, this issue has nothing to do with moving items on the screen. We're talking about totally stationary objects and text. This is not the same as the "ghosting" issue.

This issue goes away entirely if the Intel GPU is in use. It only occurs with dedicated GPU.

 

[redheeler]

Use the display's native resolution. That is, the one to the left of Default in System Preferences > Displays. This looks like a bug related to the downscaling. Apple's idiotic decision to continue to ship these MBPs with a scaled resolution by default, instead of increasing the physical resolution of the display, was bound to cause problems like this.

 

[mtoddy]

Yes, that is one "solution," but then, of course, all my screen elements are uuge.

What miffs me is that the scaling is not an issue when Intel graphics are enabled—it's only a dedicated GPU problem. That's why I'm curious if I potentially have a bad GPU.

 

[redheeler]

Yes, that is one "solution," but then, of course, all my screen elements are uuge.

You have Apple to thank for that imperfect solution. I'm stuck on the native resolution because everything on the screen looks fuzzy to me otherwise, as if a subtle blur filter has been placed on top of it, and that bugs me more than the bigger UI elements.

Apple produces the best MBP in years, but still fails to fully resolve my #1 complaint with a 3360x2100 or higher screen resolution. It's disappointing, but I decided to live with it.

What miffs me is that the scaling is not an issue when Intel graphics are enabled—it's only a dedicated GPU problem. That's why I'm curious if I potentially have a bad GPU.

I'm thinking it could just be a software bug with the GPU drivers. Are you able to reproduce it every time your MBP switches to the dedicated GPU, or does it only happen sometimes?

 

[mtoddy]

I totally agree with you on the screen resolution. My biggest peeve with this MacBook is that they didn’t put a 4K screen in it.

As for reproducing the issue, it's reproducible 100% of the time in dedicated GPU mode, and reproducible 0% of the time with the Intel GPU. So I’m hoping it could just be a lousy driver with the dedicated GPU that gets fixed at some point, but I can’t find anyone else on the internet who has the same issue...

 

[Sanpete]

There are other thread on this already.

If you have a MBP 16 inch, could you help me with a display test? Thanks!

This is a follow-up to this post. I've come up with a very reliable way to reproduce a display issue on my machine. Could you help me test it and see whether you could reproduce it? Steps: Turn ON Night Shift in the Display settings. Make sure your MBP is using the discrete GPU (launching...

forums.macrumors.com

MBP 16" - strange glitch in true tone or night mode

Hello, my 16" MBP configuration: MacBook Pro (16-inch, 2019) Ram: 32 GB 2667 MHz DDR4 SSD: 550 GB AMD Radeon Pro 5500M 4 GB Intel UHD Graphics 630 1536 MB MacOs Catalina 10.15.2 When the dedicated graphics card is running (AMD Radeon Pro 5500M 4 GB) in True Tone or Night Shift mode, some...

forums.macrumors.com

 

[mtoddy]

Bump... Does anyone know of macOS 10.15.3 fixes this issue? I've been sticking with 10.15.1 to avoid it on one machine.

 

[appleuser181]

I'm using a 2018 MBP 15" (2.6 i7, 32GB & Radeon Pro 560x) and recently noticed an issue with my dedicated gpu as well. I was wondering if it's the same issue as this post; if so, is it a hardware issue with the gpu or something that can be fixed?

I have attached a picture to show you guys what it looks like:

Also, not sure if it's a recent issue or it was always there. There is a chance that it was always there and I recently noticed it. But one thing is for sure, the issue goes away as soon as the machine goes back to integrated graphics so this only happens when the dGpu kicks in!