Question: I don't know how to install much-needed nvidia drivers on my powermac g5 quad. I am using ubuntu 14.04.2. Any help would be greatly appreciated as I cannot get into desktop

Answer: 
There are no proprietary Nvidia drivers supporting this adapter for powerpc platform. And it looks like nouveau does not support 3D acceleration well for it.

The only solution I see is to install Xubuntu. It does not require 3D acceleration and it may work with open source drivers.
Try this:

```
   sudo apt-get install nvidia-311-updates

```

and it might work.