[SOLVED] 3840x2160 resolution lag

[baron-vardus]

Hi, I bought ultra hd monitor for my laptop and connect it via HDMI (Nvidia 960m).
The whole UI is lagged. If I pick 2560x1140 or 1920x1080 resolutions, everything is smooth.
I've tried every speed-up tweak I found, nothing happens.
Any idea on how to improve it? The most notable issue is the mouse lag, the pointer goes fractions of seconds behind, and when I select text and move the mouse while clicking, that text selection animation is really lagged.
But in the end everything feels lagged.
I'm sad cos I paid a a bunch of bills and now is seems that I have to re-sell the monitor -.-

Please any advice is welcome,

Thanks!

[claydoh]

Have you installed the proprietary Nvidia drivers from the Driver manager in System Settings?.
I will bet the free, open Nouveau driver may struggle a bit in the older gpu on 4k screens, but the Nvidia driver should have no problem with it.

[baron-vardus]

Currently installed Nvidia driver: 390.48

[baron-vardus]

I tried with the Intel 530 HD graphics card and works great... but, it freezes randomly -.-

[GreyGeek]

I tried with the Intel 530 HD graphics card and works great... but, it freezes randomly -.-

What kernel are you running?
(uname -a)

[baron-vardus]

Linux kubuntu 4.15.0-22-generic #24-Ubuntu SMP Wed May 16 12:15:17 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

[claydoh]

I forgot to notice this is a laptop here. Are you trying to run dual monitors? The gpu may not have enough oomph to run a 4k screen plus whatever your laptop's screen is using. Also, how old is the HDMI cable? Not all of them support 4k video speeds, though most should.

Other than that, I can only suggest trying out different driver versions after adding the driver updates ppa:
https://launchpad.net/~graphics-driv...ive/ubuntu/ppa
You should see the beta 396 driver and perhaps the 340 driver.

[baron-vardus]

My laptop: https://www.notebookcheck.net/HP-Pav....170406.0.html
My external monitor: http://www.samsung.com/es/monitors/u.../LU28E590DSEN/
I'm using the v1.4 cable that came with the monitor.
I have dual boot with Windows 10 and it works great there.
I'm quite sure there's no hardware issues.
I'm going to test with a fresh install of Kubuntu 18.04 (this is an upgrade from 17.10), Kubuntu 16.04 and Ubuntu 18.10, just to compare different performances.
I straggle to don't use a mac for working, I'll fight till the end

I really appreciate your interest in help me.

[claydoh]

It could be an xorg config tweak, but I have no idea what it could be.
Only last thing I can suggest is to see what the nvidia settings program does as opposed to Plasma's System Settings module in configuring the screen.

[baron-vardus]

Solved it!
A fresh install did the job.
I'll never know what happened but now it works great.

Thank you very much guys!

[GreyGeek]

Solved it!
A fresh install did the job.
I'll never know what happened but now it works great.

Thank you very much guys!

Fresh install of what? Kubuntu or the NVidia drivers?