Multiple Display weirdness

[mattspace]

So I just brought a pair of Benq Sw240s online to replace my 2005 & 2010 era Dells. Short review - pretty freaking awesome right out of the box, but still waiting on a calibrator.

So, the weirdness I observed with my old displays on both the GT120 and the RX580 in Sierra is continuing.

Left Display : DVI connection : Refresh rate 60HZ
Right Display : Displayport Connection : Refresh rate 59.88 Hz (NTSC)

Monitors prefpane identifies the right/displayport display as BenQ SW240 (1), Left DVI display as BenQ SW240 (2)

Menubar and dock are on the left DVI display, but on boot the login screen appears on the right.

If I rotate the Left/DVI screen, it rotates the left display, and throws the menubar and dock to the Right/Displayport screen, swaps the screens' position relative to each other in the Arrangement part of the monitors prefpane.

If I rotate the Right/DVI screen, it rotates the right display, and takes the menubar and dock to the right display, and flips their position.

If I set the menubar to the right display, and rotate the right display, its rotation behaviour is correct - it rotates, keeps the menubar, and keeps its correct arrangement. If I rotate the left display, likewise its behaviour and arrangement is correct.

So...

• Is the 59.88 hz NTSC refresh correct for DP connections, or should I be looking for a culprit for that?
• Is this rotation weirdness the new normal? I don't use that separate spaces per screen setting.
• Is there a way to force the system to assign a particular display as the "master" display?

 

[MIKX]

It would help if we knew which GPU(s) you have installed. Make a sig with all your relevant cMP specs.
( I'm an Aussie too . .but in Japan )

 

[krakman]

My experience is that Mac OS is not very good at determining whether a monitor is actually a monitor or TV when using Displayport or HDMI cables

When it mistakenly defaults to TV, it shows the NTSC refresh rate and can also output YCbCr instead of RGB

i use a script called EIED override to fix this: http://www.mathewinkson.com/2013/03...ix-the-picture-quality-of-an-external-monitor

hope this helps

 

[mattspace]

My experience is that Mac OS is not very good at determining whether a monitor is actually a monitor or TV when using Displayport or HDMI cables

When it mistakenly defaults to TV, it shows the NTSC refresh rate and can also output YCbCr instead of RGB

i use a script called EIED override to fix this: http://www.mathewinkson.com/2013/03...ix-the-picture-quality-of-an-external-monitor

hope this helps

Both my displays are showing up as 32 bit ARGB8888 in System Information, so I assume both displays are showing the same colour space.

I'm tempted to see what happens when I get a second displayport cable, if that'll let me change the positions of the displays, or at least swap which port which display is plugged into to get them reoriented. I recall different versions of macOS seem to swap which port is the "primary". It certainly seems pretty squirrelly.
[doublepost=1534419178][/doublepost]

It would help if we knew which GPU(s) you have installed. Make a sig with all your relevant cMP specs.
( I'm an Aussie too . .but in Japan )

It's in the post - I'm using an RX580, but this behaviour happened on a GT120 as well (which also thought one of my displays was a TV)

 

[mattspace]

Latest update - putting in a Displayport to DVI adapter, and plugging both displays in to DVI, and they both show up as 60hz refresh. Swapping the connectors around so that the original DVI display is via the adapter to Displayport, and the DP display is plugged in via a DVI cable direct to the card - they didn't swap places in their arrangement in the monitors prefpane, which would seem to keep track of them based on the display themselves, rather than the port on the video card.

So, with the Left monitor now plugged into the displayport, and the right monitor plugged into DVI, rotation behaviour is correct. Now, I just need to solve the 10 bit colour issue...

I've tried Imagescience's 10 bit colour ramp test image and while it's smooth in Preview (even with 32 bit ARGB8888), using SwitchResX to set things to 10 bit (30 bit ARGB2101010) Photoshop CS5, Affinity Photo and Aperture show clear banding, so I'm assuming those apps don't output 10 bit to screen?

 

[krakman]

Both my displays are showing up as 32 bit ARGB8888 in System Information, so I assume both displays are showing the same colour space.

I just updated to Mojave and as usual the monitor Overrides that I set up in High Sierra were deleted Notice one of my monitors showing NTSC 59.98 instead of 60 HZ and the scaled resolutions include 1080i and 720p TV res.

So then I ran the force RGB script and i get correct monitor resolutions and all at 60hz