I am using an 3rd Gen i5 with HD4000 (parallel with Club 3D AMD Radeon 7870 XT (UEFI GOP compliant)) on an ASROCK Z77 Pro 3.
Latest Driver for the HD4000 (22.03.2013) are installed and Intel Display Audio shows up in the Device Manager.
Wenn I enable Windows 8 Ultra Fast Boot in Bios (CSM disabled), so that the System uses UEFI GOP an HDMI attached Philip TV is not recognized as Audio Ouput Device. With CSM enabled (UEFI GOP off) it works instantly perfect.
Are there any known Driver issues, because I red the HD4000 supports UEFI GOP.
Thanks for the support.