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2018 MacBook Pro blurry displayport output

W

weebi

macrumors newbie
Original poster
Feb 28, 2009
9
2
Hi,

I got the 2018 MacBook Pro (15", 2.6GHz, 16GB, 512GB) and tried to connect two Dell U2715H displays via two usb-c to displayport cables. The fonts on the screens were very blurry (yellowish at the edges). In the display settings, the resolution is shown correctly and the refresh rate is at 60 hertz.

Here are a few things that I noticed:
  • I bought another usb-c to displayport cable (different vendor) but I got the same results.
  • I then bought an usb-c to hdmi cable and the display worked perfectly without any blurriness at the correct resolution.
  • When connecting my rMB 12" to the display via the usb-c to displayport cable, there is no blurriness.

If it is related to the MacBook Pro, I don't get why it works with the usb-c to hdmi cable.

Does anyone have an idea why it is so blurry?

Thanks!
 
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This is inversed to my experiences. I always need to opt for DisplayPort for things to look their potential.
 
weebi said:
Does anyone have an idea why it is so blurry?
Click to expand...
My old Apple Cinema Display is hooked up to my 2018 MBP and I don't have this issue. Since its only related to when you use the displayport, and 2018 MBP, it certainly does point to the MBP not driving the monitor correctly. I have no suggestions, but you do have a work around, HDMI
 
Thanks for your replies. I will check with a 2018 13" MacBook Pro to see if it's related to my mbp or to the 2018 models in combination with displayport and the Dell U2715H display.
 
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The OP wrote:
"I then bought an usb-c to hdmi cable and the display worked perfectly without any blurriness at the correct resolution."

Fishrrman's credo re Macs:
"Use what works for you"...
 
Finally, a post! I got my 2018 15" MBP last week, and was so excited to start using it. I plugged it into my monitor, and immediately noticed a big difference in sharpness of the windows, and especially the font.

I thought I was crazy, and kept swapping between my company issued 13" MBP, and a Mac Pro. I even went and bought another brand of cable like you. No dice, it is definitely more blurry! I have a appointment at the Genius Bar tomorrow to take it in.
 
I had blurry text when I connected my 2018 15" MBP to a Dell 2713HM via usb-c to displayport cable.

I was able to fix it using the instructions here. https://embdev.net/topic/284710#3027030

It was because macos was setting the color input to YPbPr instead of RGB. Check your Dell OSD > colour settings.
After patching it forces RGB out.
 
bchin said:
It was because macos was setting the color input to YPbPr instead of RGB. Check your Dell OSD > colour settings.
After patching it forces RGB out.
Click to expand...

Thanks a lot, I will look into that one. If it is related to macos, do you have an idea why my 12" macbook is working fine? Both have the latest high sierra installed.
 
weebi said:
Thanks a lot, I will look into that one. If it is related to macos, do you have an idea why my 12" macbook is working fine? Both have the latest high sierra installed.
Click to expand...

The 2018 Macbook Pro runs a different build of high sierra.
 
It happens on both monitors? Well it could be some setting like bchin said. Do you have another monitor that you could test out the MBP/cable on? Or go to a store that sells monitors to try it out on a different model of monitor?

I've had no problems using a 2016 15" and a 2017 15" MBP with a usb-c/displayport cable on both of my monitors (24" 1200P one and a 31.5" one 4k) with that same cable.
 
I will do some more research during the weekend. Checking it with another 2018 mbp and some more dell displays (different models).

bchin's observation is correct: When connecting the display via the 2018 mbp, it is showing YPbPr. When connecting the rMB, it's showing RGB. However, it is strange that it even shows YPbPr when connecting via hdmi (no blurriness).
 
bchin said:
I had blurry text when I connected my 2018 15" MBP to a Dell 2713HM via usb-c to displayport cable.

I was able to fix it using the instructions here. https://embdev.net/topic/284710#3027030

It was because macos was setting the color input to YPbPr instead of RGB. Check your Dell OSD > colour settings.
After patching it forces RGB out.
Click to expand...

I had the same problem and the fix helped me too. I have a dell u2717D and it was showing YPbPr with horrible colors and blurry text. Once I forced RGB mode with the various patches out there, display is back to normal on my macbook pro 2018
 
joshi3joshi said:
I had the same problem and the fix helped me too. I have a dell u2717D and it was showing YPbPr with horrible colors and blurry text. Once I forced RGB mode with the various patches out there, display is back to normal on my macbook pro 2018
Click to expand...

How can you tell it’s forcing YPbPr vs RGB? I looked through the OSD of my monitor and it doesn’t show it.
 
joshi3joshi said:
for me it shows when I click through the settings of my dell monitor, under color -> "input color format"
Click to expand...

For me it is the same. With the rMB it is showing rgb, but with the 2018 mbp it is showing YPbPr (with both displayport and hdmi).
 
timeslip said:
How can you tell it’s forcing YPbPr vs RGB? I looked through the OSD of my monitor and it doesn’t show it.
Click to expand...

After patching you will see a new colour profile in System Preferences > Displays > Colour. example: "DELL U2713HM - forced RGB mode (EDID override).

timeslip said:
The colors also look quite washed out
Click to expand...

You may need to recalibrate your monitor colour profile. What monitor do you have ? I know this patch works for Dell's not sure if it fixes other brands.
 
I don't understand how this is a problem on the 2018 Macbook Pro, but my 2017 13" MBP and my wife's Macbook using TB -> Displayport works just fine.
 
Just wanted to chime in and add that I'm also facing this issue on a 2018 Macbook Pro (15", 2.6GHz, 16GB, 512GB). I see screen artifacts, fuzzy off-color text, and general blurriness when connecting using a USB-C to DisplayPort cable. I've tried 5 or 6 different brands of cables including USB-C to DisplayPort and USB-C to Mini DisplayPort. I have two HP Z27N monitors and the issue happens on both. It also happened on an ASUS monitor that I tried plugging into after bringing my computer to Micro Center. I even went so far as to exchange the computer for another identical one, and the new one exhibits the issue as well.

I haven't tried the patch above because at this point I'm tired of expending time and money trying to fix this and have resorted to using USB-C to HDMI cables, but I can confirm that this is definitely a 2018 Macbook Pro issue. I'm really surprised that no one at Apple caught this before releasing it.
 
Only got one sample point, and only actually tested with GM version, but I'm getting 4:4:4 output to my tv ( a 32" sony 1080p from maybe 3-4 years ago ) via dp based hdmi adapter.
 
UPDATE Oct 2018: Upgrading to macOS Mojave fixes this problem for me. See my post on that later in the thread.

Original Post:
So Glad To Find This Post, Here's Some Evidence!!

I have the same issue on my 2018 MBP. I think of it less as "blurry" and more as something like "chromatic aberration" (for those familiar with that distortion in photography). What's happening is an inability to have a crisp edge to a line. Instead, there is a band of color at the edge. Since small fonts have many such edges, they light up with extraneous colors.

I think the reason Apple can get away with this is because it's a subtle issue and many people won't notice it.

Here is some evidence of the issue:

I took photos (not screen captures, but photos of the screen itself). Then I cropped out just a tiny portion of the photo.
The photo is of the "About this Mac" screen, where it says "Macintosh HD". (I've found it very easy to see the problem on this screen because the fonts are small).


BAD: Using a USB-C to USB-C cable (or DisplayPort, but this image was USB-C)
usb-c_to_displayport.jpg


GOOD: Using a USB-C to HDMI cable
usb-c_to_hdmi.jpg


Hopefully those images make the problem obvious!

I've seen the problem with multiple monitors/cables:

- ViewSonic VP2771
- BAD: USB-C to USB-C (I'm most bummed about this!!!)
- BAD: USB-C to DisplayPort
- GOOD: USB-C to HDMI

- ViewSonic VP2468
- BAD: USB-C to DisplayPort
- GOOD: USB-C to HDMI

- Dell U2415
- BAD: USB-C to DisplayPort
- GOOD: USB-C to HDMI

In all cases I've tried, using the HDMI input on the monitors works.
Using DisplayPort or USB-C inputs on the monitors makes for the result shown in my first image.

I'm don't want to attempt to hack my OS. I'll just use the HDMI cables.

Huge disappointment that I can't use my USB-C to USB-C cable and get the best possible image!
 
Last edited:
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yes, you have the same issue - You are welcome to use the HDMI cable. However, this fix worked for me * I have your exact setup. This fix modifies the file tied to your monitor that gets generated the first time you plug it in (it's dynamic) and not a real system file. However, I understand your concern, and think it's crazy that Apple hasn't fixed this...
 
ddanger said:
BAD: Using a USB-C to USB-C cable (or DisplayPort, but this image was USB-C)
View attachment 784052

GOOD: Using a USB-C to HDMI cable
View attachment 784053
Click to expand...

Exactly the same issue for me. Was using a 13" 2017 TB MBP though a Dell USB-C dock to a dell monitor connected with DisplayPort (can't remember the specific model) since Feb 2018 with no issues. Upgraded to 2018 15" MBP and immediately noticed exactly what the above pictures show. Switching to HDMI, the difference was like night and day. I even noticed the colours looks better so the other fix makes sense. Happy to stick with the HDMI cable though in my case.

Glad to see it's not just me!
 
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