New
#11
Keep in mind that it may be your (older) motherboard, or more specifically, the motherboard's BIOS that may not be up to the task, not the video card.
You might want to try contacting Gigabyte (ugh) and explaining your issue (onboard sound chip being disabled by HDMI capable video card in BIOS) and see if they have a fix or workaround you could use. It will take some perseverance to get to a real tech who can actually help.