Fuzzy graphics and texts over HDMI, but perfect over DP

[Lawris]

Hey there,

I have a 3 identical monitors setup with a graphics card that has 2 DP and 2 HDMI ports, so my third monitor needs to be over HDMI.
But here is the thing, over DisplayPort, graphics are perfect but with HDMI the graphics and texts look a bit more pixelated and fuzzy, it's a slight annoyance.

I don't really know where to start, since I didn't find anything on the internet that was close to my issue with the HDMI itself, while Display Port is looking good.

Here is my config:
CPU: i7-7700K (Kaby Lake)
GPU: AMD Radeon RX 580 8GB
MB: Gigabyte GA-H270 Gaming 3
Monitors: LG 27UD88-W PC LED IPS - 27" - 3840 x 2160 UHD 4K

What I tried so far:

• Changing HDMI cable: ordered a superfast rated HDMI cable, didn't work;
• Booting on Windows: the issue disappears, clear and sharp graphics over HDMI;
• Using my MacBookPro with a USB-C to HDMI adapter, clear and sharp graphics;
• Tweaking my monitors settings. I toggled off the "ULTRA HD RESOLUTION", the graphics look sharper, but the refresh rate is capped at 30Hz instead of 60Hz

So, from what I've tried, it seems that the issue is coming from the software side.

Attached is my EFI folder.

What could I look into?

Regards,

Loris
https://www.amazon.fr/gp/your-accou...8&ij=&opt=ab&ref_=&search=407-8874639-4833139

 

[EliteMacx86]

Hey there,

I have a 3 identical monitors setup with a graphics card that has 2 DP and 2 HDMI ports, so my third monitor needs to be over HDMI.
But here is the thing, over DisplayPort, graphics are perfect but with HDMI the graphics and texts look a bit more pixelated and fuzzy, it's a slight annoyance.

I don't really know where to start, since I didn't find anything on the internet that was close to my issue with the HDMI itself, while Display Port is looking good.

Here is my config:
CPU: i7-7700K (Kaby Lake)
GPU: AMD Radeon RX 580 8GB
MB: Gigabyte GA-H270 Gaming 3
Monitors: LG 27UD88-W PC LED IPS - 27" - 3840 x 2160 UHD 4K

What I tried so far:

• Changing HDMI cable: ordered a superfast rated HDMI cable, didn't work;
• Booting on Windows: the issue disappears, clear and sharp graphics over HDMI;
• Using my MacBookPro with a USB-C to HDMI adapter, clear and sharp graphics;
• Tweaking my monitors settings. I toggled off the "ULTRA HD RESOLUTION", the graphics look sharper, but the refresh rate is capped at 30Hz instead of 60Hz

So, from what I've tried, it seems that the issue is coming from the software side.

Attached is my EFI folder.

What could I look into?

Regards,

Loris
https://www.amazon.fr/gp/your-accou...8&ij=&opt=ab&ref_=&search=407-8874639-4833139

Before we jump to the debugging, can you provide a zipped photo of the picture from the DP and the HDMI?

Also, have you tried the supplied HDMI Cable that came with your monitor?

 

[Lawris]

Hello,

Thanks for your reply.

Yes, I first tried the supplied HDMI cable from my monitor (all three of them actually in case one was faulty). That is also why I ordered a new, faster-rated, HDMI cable to test if I was being limited by the bandwidth of the supplied ones.

Here is the zipped picture from the DP and HDMI comparison. Unfortunately, it is not as obvious on the phone's camera as it is with the human eye.

But you can see that the HDMI looks more pixelated, (especially on the line separating the green and red part of the Chrome's logo).

 

[EliteMacx86]

Hello,

Thanks for your reply.

Yes, I first tried the supplied HDMI cable from my monitor (all three of them actually in case one was faulty). That is also why I ordered a new, faster-rated, HDMI cable to test if I was being limited by the bandwidth of the supplied ones.

Here is the zipped picture from the DP and HDMI comparison. Unfortunately, it is not as obvious on the phone's camera as it is with the human eye.

But you can see that the HDMI looks more pixelated, (especially on the line separating the green and red part of the Chrome's logo).

What macOS version are you running?

Check your inbox!

 

[Lawris]

I'm running macOS Sonoma 14.3.1