You need to disable the nvidia graphic "co-processor" first; and then 
use the intel integrated graphics.  (Because your bios gives no method 
to disable it there)

# yum groupinstall "Development Tools"
# yum install git
$ cd /tmp
$ git clone https://github.com/mkottman/acpi_call.git
$ cd acpi_call
$ make
$ sudo insmod acpi_call.ko
$ lspci -vnnn | grep VGA
$ ./test_off.sh
$ lspci -vnnn | grep VGA
$ startx    (make sure you have no old xorg.conf being used)

Did the nvidia card get turned off?  If so, install the acpi_call 
module.  Write a script that loads the module, disables the nvidia card, 
and starts X, gdm or whatever.

Hope this helps.  No, I didn't test it; I don't have the hardware.  I 
did build and load the module and ran the script on my machine and 
nothing blew up.

Good luck

Chris