LG UltraFine 5K Build

[FabioPeterhans]

So I got my Alpine Ridge Card, wanted to try it.
Before I was using the Asus Thunderbolt EX3 AIC (add in card), that has only one DP 1.2 in port.
=> i want to upgrade to the Gigabyte Alpine Ridge Card, because it has two DP 1.2 in ports. (in order to us the LG 5K display with a 5K resolution, instead of only 4K that was able with the Asus Thunderbolt EX3)
However, when I try to put it in, the pwr_led on the Asus Z170-A Motherboard goes from green to off...
=> nothing happens, cannot press any power buttons. The System works fine, once i remove the thunderbolt PCIe card again..

=> semms to be a compatibility issue(?)
=> do I have to buy another motherboard in order to be able to use the alpine ridge AIC (add in card)?

If anybody can help me out with these questions it is highly appreciated, thanks.

 

[ffffwh]

Try nv_spanmodepolicy=1 flag metioned in https://www.tonymacx86.com/threads/...drivers-on-dell-ultrasharp-27-monitor.158311/ .

For anyone achieving 5K with one DP cable, make sure that the image is sharp enough. It might be the case that image is rendered in 5K, scaled down to 4K by OS, transmitted and finally scaled up to 5K by monitor.

Also, check what will happen in MS Windows.

 

[joevt]

Actually 2560x1440 is Retina mode when using a Retina monitor.
"Normal" 2560x1440 is displayed as low res

And this is screenshot from my 2016 MacBook Pro:

You can also tell the difference between HiDPI and low res by looking at the size of the text, buttons, menu bar, title bar, etc. in the screen shots.

I installed SwtchResX and this is the pic
Interesting now I set my monitor at 3008x1692 in retina mode and screen go perfect...Incredible
If you see the selection i take as istantanea is 5180x2668

3008x1692 HiDPI is drawn in a 6016x3384 frame buffer, which is why your snapshot selection size is 5180x2668. The frame buffer of 6016x3384 is scaled down by the graphics card to the resolution of your display, which you have not shown yet.

To show the resolution of your display, you need to double click the current resolution (the selected radio button at 3008x1692 HiDPI). This will show the pixel clock and active pixels.

These are my resolutions:

This is the timing information for the current resolution:

The Display Information tab also has useful information:

 

[janmansilver]

Hi nv_spanmodepolicy=1

Does not seem to make any difference unfortunately :-/

 

[joevt]

Hi nv_spanmodepolicy=1
Does not seem to make any difference unfortunately :-/

Yet it's necessary, because I can't get my Dell display to do 5K without it. Even so, after I start up, I see two displays are connected, but can only see video for one of them and it's not 5K. I have to disconnect both DisplayPort cables, and then reconnect them, then the display is in 5K mode. My Dell display shows as two AppleDisplay objects under NVDA,Display-B and NVDA,Display-C in the IORegistry. They have different serial numbers and EDID information. SwitchResX only shows one display and it has 5K resolution.

Does disconnecting and reconnecting the Thunderbolt cable while macOS is running allow 5K to work? Does disconnecting and reconnecting the DisplayPort cables while macOS is running allow 5K to work? If neither of those work, then maybe there's a programatic method to make it work, like disable the screen, then reenable it or something.

The fact that this boot argument is needed to work with MST displays shows how behind the Nvidia drivers are compared to AMD. Plus there's the cursor issue where the cursor can differ between the left and right side of the display.

Maybe High Sierra will improve things for Nvidia, but Apple made no mention of Nvidia, even when they discussed the eGPU support.

 

[janmansilver]

Hi, unplugging the DisplayPort cables and the TB 3 cable in various ways in combination with the nv_spanmodepolicy=1 boot flag did not make a difference with my Ultrafine 5K monitor unfortunately.

 

[FabioPeterhans]

So I also installed the alpine ridge card on my Gigabyte Z270X UD5. In Windows the LG5K Screen works great.
in macOS the operating systems detects sometimes two, sometimes three displays, but I never get a picture on the LG 5K screen. (with only two screens connected,the LG 5K screen and a second DP or HDMI screen.)
I am able to use the computer with the remote control software VNC. => see screenshots attached.

It does work in macOS, when I use it in 4k (1080p HiDPI), with only one DP 1.2 cable from the graphics card to the alpine ridge aic. As soon as I insert the second DP 1.2 cable, i get the black screen.

Does anybody know, whether its possible to use it in 5K? Would it work with an AMD card? (I use a NVidia GTX 1080, is this the reason the screen cannot stich the two pictures together?)

 

[Stork]

See Azimuth1's thread Enabling 5K display with ATI Radeon RX480/580 for more useful information on 5K display use.

 

[bluepr0]

So... still now way to use the Ultrafine 5K at actually 5k?

 

[blueshadow869]

@wildwillow, thanks for shielding issue link. I called Apple, they extend the refund period to 1 month. And I ordered the refund. Going to drop off the monitor to Apple Store tomorrow. My be consider a Dell 4K monitor instead. Look like 4K is good enough for me.

I also have the GA-Z170X-Gaming 7, can you explain how your setup works, how did you connect your graphics card to your motherboard?

Also did this work with Windows as well and did you need to install any special drivers to make it work? Thanks!