HD6870 Sierra update : 16-bit color gradients, blur and shadows

[noambbv]

Hey,
My monitor is Dell 1440p U2515H, and I'm having a problem since I updated to Sierra.
The gradients, blur effects, and shadows look weird. Not fuzzy, but less color accuracy. for instance, a shadow would look like strips of gray colors instead of a real gradient. It's difficult to capture on camera, but I tried my best. Look at the image and try to see that the blur looks different than it should be..
The fun part is that when you take a screenshot, the image itself actually looks good. Gradients and all. so I can't upload a screenshot.
Oh, what's weird is that when I lower the resolution from 1440p to 1080p I think the problem is completely gone, at least to my eye. Only when I return the monitor to 1440p I can see this issue.

This is new to me, only in Sierra I came across this.
From system report:
DELL U2515H:
Resolution: 2560 x 1440 @ 59 Hz
Pixel Depth: 32-Bit Color (ARGB8888)

I think the real pixel depth of the monitor is not 32 bit(or maybe it is?). Could it be the source of the problem?

Thank you!!
(Oh, and if anybody here remembers that blinking problem with that monitor under OS X, it's still here, but much less often, so it's usable)

Oh, and I have QE/CI enabled, because I see ripples when adding a new widget in the Dashboard (I read this was one way to check that out)

 

[P1LGRIM]

The fun part is that when you take a screenshot, the image itself actually looks good. Gradients and all. so I can't upload a screenshot.

If the screenshots look good then the OS is doing its job and the problem lies elsewhere.

Check cables / connectors / monitor menu settings / adaptors if any

 

[noambbv]

If the screenshots look good then the OS is doing its job and the problem lies elsewhere.

Check cables / connectors / monitor menu settings / adaptors if any

It surely has to do with software, because wallpapers and apps icons look as they should. And I've never had anything like this in Windows.

This problem began after software update, so Im pretty sure there's some settings to tweak. Maybe EDID?

 

[Fl0r!an]

Looks like low color depth, although 32bit is fine (well, it's actually 24bit as your monitor obviously has no alpha channel, but that's the way OS X reports it).

How did you connect it, HDMI or DP? Never had such an issue on my U2515H with any GPU.

 

[noambbv]

Looks like low color depth, although 32bit is fine (well, it's actually 24bit as your monitor obviously has no alpha channel, but that's the way OS X reports it).

How did you connect it, HDMI or DP? Never had such an issue on my U2515H with any GPU.

HD6870 -> mDP to DP -> U2515H
I have never had this issue too, until updating to Sierra. Very strange.
Although I did have (and still do, to a certain extent) the blinking problem that you tried to help me resolve, but we couldn't figure it out.. Not sure if this has anything to do with the color depth though.
https://www.tonymacx86.com/threads/dell-monitor-blinks-hd-6870-video-inside.199182/

 

[noambbv]

UPDATE:
after updating to 10.12.1, the colors are back to normal.
However, the blinking that I described in the other thread (https://www.tonymacx86.com/threads/dell-monitor-blinks-hd-6870-video-inside.199182/ ) is much much more often than under 10.12.0.
I actually can make do with the 16bit colors and let the monitor function properly...

Do you have any idea what Apple changes in their drivers? because 10.12.0 almost fixed the blinking problem in exchange of poor colors, but now the colors are back, and so are the blinks.
Is there any way I could compare both drives/kext and understand what causes those damn blinks?

Thank you so much for helping !

 

[Fl0r!an]

I'm starting to think it's an issue with your specific GPU (or your display?). Two strange and rare problems like this can't be a coincidence...

One would need to disassemble the drivers to compare them as Apple doesn't release the source code, but that's usually close to impossible in such a huge binary with lots of changes.

 

[VioletDragon]

Upload screenshot of the full screen. Can't tell much from the screenshot you've provided.

 

[winstonchiu]

Hi Fl0r!an,

I have the same issue when I upgraded to Sierra from Yosemite.

I wonder if you've been able to find a solution.

Attached is the screen shot.

Many thanks
Winston

 

[VioletDragon]

Hi Fl0r!an,

I have the same issue when I upgraded to Sierra from Yosemite.

I wonder if you've been able to find a solution.

Attached is the screen shot.

Many thanks
Winston

Attach config.