I followed the tutorial in OP for the latest Gigabyte GA-EX58 EXTREME bios from gigabyte's website, F13s. All went well but when I replaced the old DSDT.aml taken form tonycrap's DSDT database that was for F12 with the one that resulted from this tutorial, I would have no sound detected.
To note, I am not using a patched HDA, I am using HDA rollback method under 10.7.2 provided through tonycrap's multishit solution.
That said, I had 25% FPS increase in Cinebench with the new one!
Any ideas on how to restore audio?