[SOLVED] Can't run 4K @ 60Hz on LG 27UD68-B Monitor via HDMI with Nvidia Quadro K4000

[gqchen1]

My setup:

Windows 10 Pro OS
Nvidia Quadro K4000
LG 27UD68 Monitor

My connection is like the following
Quadro K4000 Displayport1.2 => Plugable Active Mini DisplayPort to HDMI 2.0 Adapter (also tried club-3d adpater) => HDMI 2.0 cable (Amazonbasics HDMI 2.0 cable, Syncwire HDMI 2.0 Cable, my old hdmi cable)

can only get 4K working on 30Hz (also verified from Nvidia Panel)

Following some advice in the internet,
1 turn on LG Ultra HD deep Color in the setting, the screen will malfunction
2 change the screen from Wide to Origin or 1:1, No difference


My last option is to try some more expensive HDMI 2.0 cable from Amazon to see if any other cables work.

Any suggestions will be greatly appreciated,

 

[SoNic67]

For my 4k monitor I am using directly the DP cable. I recommend that you use the same, no adapters from DP to HDMI!

 

[gqchen1]

Thanks, SoNic67.
Yes, with direct DP to DP, it works fine at 60HZ for 4K. The problem is that sometimes I have to share the same LG monitor between my laptop and desktop.
I need to switch between them (Laptop uses DP port, so the desktop has to use DP to HDMI 2.0 adapter to connect the hdmi port of LG monitor.

 

[SoNic67]

Put the laptop on HDMI. That's what I do... It has less horsepower anyway (even if mine has a Quatro video card too, it's an older K610M).
The weak link is the adapter from DP to HDMI.

 

[racksmith101]

Just get one of these.
https://www.amazon.co.uk/dp/B00ZK2S71W/ref=asc_df_B00ZK2S71W57909251/?tag=googshopuk-21&creative=22110&creativeASIN=B00ZK2S71W&linkCode=df0&hvadid=309841464204&hvpos=1o1&hvnetw=g&hvrand=4641849396123023306&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9045046&hvtargid=pla-350073804665&th=1&psc=1

 

[junglist724]

This sounds like a signaling problem. Cable quality, cable length, use of adapters or couplers, and even quality of the video outputs on your video card will all have an effect on signal strength/quality.

I've had situations where swapping gpus or cables fixes hdmi signalling problems. In one particular case we were running a dp to hdmi adapter to a wall plate with even more hdmi cabling going through the wall and started randomly losing signal on the TV. I tried plugging in a laptop(that I know has low signal output) and it had no problem. Ended up getting a GT 710 video card to both replace the iGPU and eliminate the dp to hdmi adapter and have had no problems since.

You could also try a signal booster/repeater but I haven't had much luck with the one I got, though I haven't tried it with the optional AC adapter.