Ttgjyuk

Same happened to me. Make sure:

1. You have less to no Gnome extensions. They can kill your computer. So, disable all Gnome extensions to see if that helps.


2. Disable animations from Gnome Tweak. That made my desktop super fast.


3. Nvidia 396 is really laggy for me as well so use the 960 one.

Unfortunately Gnome on 18.04 is really slow, even with the newest hardware (e.g. Dell XPS 13). If you wanna have a good experience on the LTS without switching to 18.10, the solutions are:

1. Using unity. You can choose it before logging in with your user.




2. Waiting until 18.04.2 update. Some patches of Gnome should be backported to LTS. We only can hope, that it will be the ones which make Gnome 3.30 faster.

I stopped using Gnome 3 on Ubuntu 18.04 and replaced it with the Mate desktop using the lightdm display manager.

To replicate:

sudo apt install tasksel
sudo apt update
sudo tasksel install ubuntu-mate-desktop
sudo dpkg-reconfigure lightdm
sudo shutdown -r now

I was experiencing a lot of lag on the splash screen with 18.04 and wanted to put this here as another solution. In my case I had been using an open source graphics card driver (Nouveau) instead of the Nvidia proprietary and it looks to have been the cause of the issue.

1. Go to Ubuntu Software app.


2. Open Software & Updates from the app's dropdown in the task bar.


3. Go to the Additional Drivers tab and see if you aren't using the recommended driver for your graphics card.

Once I switched from the Nouveau display driver to the Nvidia driver metapackage 390, everything ran much more smoothly.

Source

AFAIK Gnome doesn't work on 18.04 nVidia.

I was able to get 144 FPS on Compiz on 18.04 + GSYNC. (I only got like, 40-60 fps on Gnome and no GSYNC)
The first time I tried Compiz, it didn't work (I was on nVidia 396)
I did sudo ubuntu-drivers autoinstall (which put me on 390) and I rebooted then used the little picker icon on login to choose Compiz and it worked great. So I think 396 doesn't work with compiz yet but 390 does. Oddly 390 on Gnome makes me physically nauseous with my monitor but it's fine on compiz, so i think 390 on Gnome has a lot of strange refresh rate / redraw issues.

(It may be a GSYNC thing but I did get a pixelated word "NORMAL" in the upper right, which I got rid of by turning OpengGL flipping off in nvidia-settings)

The issue seems to be caused by Wayland as described here and here. You can try to access /etc/gdm3/custom.conf ( or /etc/gdm/custom.conf for older versions ) and uncomment WaylandEnable=false. It worked for me.

The problem usually start when you update Nvidia driver up to version 390 or above. It is possible that the fallback to Xorg stopped working in latest versions, and then GDM uses Wayland to manage the display instead.

So I feel some of these answers are sub par. I've installed Ubuntu 16/18 on multiple machines at work at and at home and have experienced at times similar issues to what you are seeing.

First let's look at some potential problems.

If you have a NVIDIA graphics card and you're doing a minimal installation of Ubuntu 18.04.02, you will notice that NVIDIA drivers (as well as non-NVIDIA) drivers are being installed. This is part of the problem.

Normally how I deal with this issue is immediately at the login screen press CTRL+ALT+F3 to enter into a terminal and purge all drivers. However, this morning I was unable to do so for some odd reason.

My Solution

1. Normally, when you have a NVIDIA graphics card your motherboard (in my case MSI) will disable the Intel Integrated Graphics. You want to enable this (optionally, disable your graphics card). Please see your motherboard's settings/documentation on how to do this.




2. Shut the desktop down.




3. If you have your HDMI cable (or whatever) plugged into your graphics card, remove this and plug it into your motherboard's HDMI port.




4. Turn on your desktop.




5. Your desktop should be starting up normally now. If it is not, then you know it is not a NVIDIA graphics driver related issue.




6. If things are running smoothly, please go into Software & Updates > Additional Drivers and select whatever NVIDIA driver option you have. This is the easy way to install those NVIDIA drivers. The hard way is to manually download them from NVIDIA. As of this morning I installed nvidia-390 which was the default option I was given.




7. After installation, restart your computer. If things are running smoothly, restart the computer once again, but this time go into your motherboard's BIOS.




8. Re-enable your NVIDIA graphics card. Save settings and restart.

At this point, your desktop should be working normally as with the Intel Integrated Graphics. There's nothing tricky, no third party software (aside from NVIDIA) that needed to be installed. It's really that simple. However, depending on your hardware, the solution may have some variance.

Use the version for your graphic card, I have the same problem, don't use de autoinstall configuration. In your case this

sudo apt-get install nvidia-396

I had to search like this --> nvidia driver "your graphic card" linux