@Deepak,

Thanks for following my guide! Based on your system and error message, it looks like the issue is related to driver compatibility and potential kernel module conflicts.

Here are some steps to troubleshoot:

1. Run the following to check if the installed driver matches your GPU:

nvidia-smi
modinfo nvidia | grep version

If it doesn’t match 550.54.14, you’ll need to install the correct version.

2. Before installing a new driver, clean up old installations.

sudo apt remove --purge '^nvidia-.*'
sudo apt autoremove
sudo reboot

Since the .run installer is failing, Nouveau might be interfering, check if it’s loaded:

lsmod | grep nouveau

If Nouveau is active, disable it:

echo "blacklist nouveau" | sudo tee /etc/modprobe.d/blacklist-nvidia-nouveau.conf
echo "options nouveau modeset=0" | sudo tee -a /etc/modprobe.d/blacklist-nvidia-nouveau.conf
sudo update-initramfs -u
sudo reboot

4. Since the official Debian package doesn’t support 550.54.14, you’ll need to use the .run file:

wget https://us.download.nvidia.com/XFree86/Linux-x86_64/550.54.14/NVIDIA-Linux-x86_64-550.54.14.run
chmod +x NVIDIA-Linux-x86_64-550.54.14.run
sudo ./NVIDIA-Linux-x86_64-550.54.14.run

5. Rebuild Kernel modules & reboot.

sudo dkms autoinstall
sudo modprobe nvidia
sudo reboot

6. After reboot, check if nvidia-smi works.

nvidia-smi

If you still face issues, let me know what error you get! Hope this helps.

I followed your recent blog about installing Nvidia drivers on Debian 12. However, I am encountering an error, possibly due to a different GPU than yours.

System Info:
OS: Linux vultr 6.1.0-30-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.124-1 (2025-01-12) x86_64
GPU: NVIDIA Corporation GA102GL [A40] (rev a1)

All commands execute correctly except nvidia-smi, which returns:

NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver. 
Make sure that the latest NVIDIA driver is installed and running.

Findings:
It seems the installed NVIDIA driver is unsupported.
The 535.216.01 driver doesn’t support Debian 12. (NVIDIA Docs)
The latest available Debian package (nvidia-kernel-dkms) is outdated.
550.54.14 does support Debian 12, but only a .run file is available

Additional Issue with .run File:

ERROR: Unable to load the kernel module 'nvidia.ko'. This happens most 
frequently when this kernel module was built against the wrong or 
improperly configured kernel sources, with a version of gcc that 
differs from the one used to build the target kernel, or if another 
driver, such as nouveau, is present and prevents the NVIDIA kernel 
module from obtaining ownership of the NVIDIA device(s), or no NVIDIA 
device installed in this system is supported by this NVIDIA Linux 
graphics driver release.

Would appreciate any suggestions on resolving this. Thanks!