update-nvidia-driver

I have followed this answer https://askubuntu.com/a/1056128

$ uname -a
Linux melisa-pc 4.15.0-128-generic #131-Ubuntu SMP Wed Dec 9 06:57:35 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

$ cat /etc/os-release

NAME="Ubuntu"
VERSION="18.04.4 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.4 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic

$ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation Device 591b (rev 04)
01:00.0 VGA compatible controller: NVIDIA Corporation GP106M [GeForce GTX 1060 Mobile] (rev a1)

Currently nvidia-390 driver is installed. To install nvidia-driver-440 followed these steps
$ sudo apt-get purge nvidia*
$ sudo add-apt-repository ppa:graphics-drivers
$ sudo apt-get install nvidia-driver-440
$ reboot

$ lsmod | grep nvidia
nvidia_uvm            974848  0
nvidia_drm             49152  7
nvidia_modeset       1179648  12 nvidia_drm
nvidia              19677184  531 nvidia_uvm,nvidia_modeset
drm_kms_helper        172032  2 nvidia_drm,i915
drm                   401408  11 drm_kms_helper,nvidia_drm,i915

$ lsmod | grep nouveau

$ nvidia-smi
Thu Dec 31 12:22:50 2020       
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 450.80.02    Driver Version: 450.80.02    CUDA Version: 11.0     |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|                               |                      |               MIG M. |
|===============================+======================+======================|
|   0  GeForce GTX 1060    Off  | 00000000:01:00.0  On |                  N/A |
| N/A   57C    P5    10W /  N/A |    322MiB /  6078MiB |      6%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+