Hello! Installing legacy NVIDIA drivers on a newer kernel can sometimes be a bit challenging due to compatibility issues. Since you've already tried installing the NVIDIA 390.xxx driver without success, you may want to consider a few things:
1. Check Driver Compatibility: Ensure that the legacy NVIDIA driver version you are trying to install is compatible with your NVIDIA Fermi graphics card. Sometimes, newer kernels may not fully support older drivers.
2. Kernel Modules: Legacy drivers might require specific kernel modules. If these modules are not loading correctly, the driver may not work as expected. You can check the kernel module status using lsmod command.
3. Blacklisting Nouveau: If you decide to switch to the NVIDIA proprietary driver, it's recommended to blacklist the Nouveau driver to prevent conflicts. You can do this by adding nouveau.modeset=0 to your boot parameters and creating a blacklist file for Nouveau.
4. Hybrid Graphics: If you are using hybrid graphics (like NVIDIA Optimus), setting up hybrid graphics with the proprietary NVIDIA drivers can be tricky. Tools like bumblebee or nvidia-prime can help manage hybrid graphics setups.
5. Testing with Nouveau: If you are not gaming and just want a stable desktop experience, sticking with the open-source Nouveau driver might be a good option. Nouveau drivers are included by default in most Linux distributions and provide basic functionality.
6. Community Support: Since Manjaro is a popular distribution, you can seek help from the Manjaro community forums or subreddit for specific guidance on installing legacy NVIDIA drivers on your system.
In conclusion, if you are not gaming and the Nouveau driver meets your needs, it might be a simpler and more stable choice for your setup. However, if you still wish to proceed with the NVIDIA proprietary driver, ensure compatibility and follow specific guides for legacy driver installation on Manjaro.
PH