27" QHD monitor image problem (Acer B276HUL)

[Moonjumper]

I have just upgraded the monitor connected to my late 2013 15" rMBP. I was using a 24" 1920x1200 CCFL-backlit HP ZR24w. I have just bought a 27" 2560x1440 flicker-free LED-backlit Acer B276HUL to replace it. The same mini-DisplayPort to DisplayPort cable has been used for each monitor.

Image quality on the new 27" monitor is awful. It looks like the image is being scaled or processed aggressively. Text is particularly bad. Stroke width varies from almost disappearing to blocky, often with a halo.

Settings for the monitor is set to "Default for display". Changing to Scaled shows that 2560 x 1440 is selected. A screen grab produces an image of the correct resolution (and shows no problems when viewed on the laptop display).

The monitor has a "Wide mode" menu option which I have set to "1:1", but have also tried "Full" and "Aspect". The "DP" setting is set to "DP 1.2", but have tried "DP 1.1".

Does anyone have any suggestions please?

 

[campyguy]

Try the following:

• Restart your Mac in "Safe" mode (hold Shift Key upon start up)
• Open the Displays Pref Pane in System Preferences
• You should be able to select the 2560x1440 resolution and use the display as "normal"/default with no flickering/distortion
• Restart your Mac normally
• Cross your fingers...
• Your new display should retain the 2560x1440 display settings you set while in Safe Mode

I also recommend using a DP-compliant cable, like the Accell cables we use in my office now. My Macs and PCs can now properly read a display's EDID info now, and we have no more issues when moving our computers from office to office and connect to different displays.

 

[Moonjumper]

Thank you for your help campyguy.

The monitor did not display in Safe mode. I tried reconnecting, turning on/off, and Detect Displays, but none worked. I had to disconnect and reconnect again after returning to normal mode to get the monitor to display again. so unfortunately that avenue is not open to me. What difference would that give to the 2560x1440 resolution I am already getting?

I read about EDID. The Mac knows what monitor is connected. The Display option in System References says an Acer B276HUL is connected, and there is the Acer B276HUL display profile in the Color page. Is there more info the EDID should give?

The more I have searched, the more it seems to be an edge enhancement or similar issue. My Mum has a Toshiba TV with a Resolution+ feature to enhance lower resolution images when seen on the 1080p of the screen. However, 1080p sources are degraded as they are processed when not needed. This results in text becoming less readable in exactly the same manner as I am getting on my monitor.

 

[Moonjumper]

Used Acer Live Chat to try and get a solution. They disconnected without warning as soon as it was obvious it wasn't a simple answer.

 

[Fishrrman]

A question:

Is the Mac "seeing" the monitor "as a TV", and -NOT- "as a computer display" ??

Try this:
- open Displays pref pane
- click "scaled"
- do you see things like "1080p" listed with the available resolutions?
Report back here.

 

[Moonjumper]

A question:

Is the Mac "seeing" the monitor "as a TV", and -NOT- "as a computer display" ??

Try this:
- open Displays pref pane
- click "scaled"
- do you see things like "1080p" listed with the available resolutions?
Report back here.

Scaled options are:

2560 x 1440
2048 x 1152
1600 x 900
720p

 

[Fishrrman]

OP wrote:
"Scaled options are:
2560 x 1440
2048 x 1152
1600 x 900
720p"

The fact that you're seeing "720p" might indicate that your display is being "detected" as a TV, instead of a "computer monitor". This seems to be a common problem lately, I had it myself when connecting the Viewsonic 2770 display I use to my late-2012 Mac Mini.

When you look at the Displays pref pane, do you see a control for "overscan", or something along that line? Again, that would indicate "tv" instead of "monitor".

Also, there is a way to -FORCE- the Mac to recognize the display "as a monitor", but it entails some fiddling and finageling.
Go to this page to read up on it:
http://www.ireckon.net/2013/03/forc...ix-the-picture-quality-of-an-external-monitor

 

[Moonjumper]

Thank you very much Fishrrman, that worked.

It seems a common problem according to the link you provided. I hope Apple does something about it to stop think their monitors are faulty, and those that find the solution people can stop messing around. I will submit a bug report to Apple.

 

[campyguy]

A little late getting back to this thread, had an emergency road trip to take...

It's good that you've got something up and running for now, but I'm going to stick to my recommendation to replace your cable - I used hacks like the one linked to, and SwitchResX and they worked OK. That EDID hack propagated on the Windows side a few years earlier.

Short bit. We have about 60 displays in my offices, and the brand that worked every single time were the spendy Eizo displays on our CAD PCs and Mac (that's single Mac, running Vectorworks). We also never had any issues with the single Apple TB Display before I sold it. We had issues with our Dells and Acers on both OS platforms, it was a bit annoying to offer the least...

Apple's TB cables are VESA/DP compliant (DP 1.1a). Eizo's cables are VESA/DP 1.1 compliant. Accell's DP and mDP>DP cables are DP 1.1 or 1.2 compliant. Dell/ASOS/Acer/HP DP cables are not VESA/DP compliant. I swapped out the non-compliant DP cables we were using for Accell cables - no more issues. There will be naysayers about this, but I've got better control over my displays now - without hacks and utilities - than ever before.

I don't agree with the perspective that Apple needs to do more with displays as peripherals. I now believe that display sellers need to stop selling/including cheap crap non-compliant cables and displays that adhere to VESA/DP standards. Cheers!