Re: Amazon EC2 PBuffer FBO rendering dual Tesla xconfig EE /dev/fb0
Did nvidia-xconfig create an /etc/X11/XF86Config file? If so, please rename it to /etc/X11/xorg.conf. XF86Config hasn't been used in many years.
libfbdevhw is used by the Cirrus driver driving the primary display device. The Tesla devices are not being configured to use the NVIDIA driver at all because the X server is not finding your configuration file and is falling back to the default configuration.