I have similar hardware to yours but I have no graphic card. I use the Intel HD2500 which is built into the microprocessor IVY Bridge i5 3450.
My configuration: Ga H77-DS3H / i5 3450 / 2x8GB DDR3 Kingston / HD SSD 240 GB with 2 partitions (one for ML and one for Win7) plugged in the blue slot (SATA2)
The bios version is the same that comes with the motherboard. I'm afraid to update at the moment. I have modified the hard drive to AHCI mode.
I made a boot usb with Unibeast 1.5.3. and Mountain Lion 10.8. I get boot my hackintosh from the usb. I managed to reach the MacOSX Desktop and I have run the Multibeast Mountain Lion 5.3 with 3 options: DSDT- Free instalation, generic audio vodoo and the network for gigabyte mobo's.
Then I restart
without USB and
it doesn't boot. It asks me to restart, and restart and restart...
I have tried to make my "USB Boot" with Unibeast and after this, using the Bridge Helper 5.0, but it doesn't finish the USB with success. It says that there is a problem.
Now I am trying to learn how to use the chameleon software because I found a post wich coments a succesfull experience with Intel HD 2500:
http://www.insanelymac.com/forum/topic/282521-will-hd-2500-work-with-ml-108/
While.... Anybody can help me?
I can't use less RAM than 8GB, could it be a problem?
Many thanks in advance