Hi, I'm wondering if I need a soundcard or not for my new build.
I'm getting the Gigabyte GA-X58A-UD3R, here is the link.
I'm worried that when I get a 5.1 surround sound system that I'll run into issues setting it up without a sound card, if Im planning on getting a 5.1 sound system, do I need a sound card? or will this motherboard suffice?
I would try it with the onboard sound, maybe. You have 8-channel and both optical and coaxial SPDIF outputs. One thing, though--what do you mean by "5.1 surround sound system"? If it's a dedicated speaker setup like Logitech's (don't get me wrong, I am NOT recommending that), you're in business. If you mean SPDIF to a receiver setup, then to get surround sound from games you'll need a sound card with Dolby Digital Live or DTS Direct. Unless your video card and receiver both do audio through the HDMI, and you're running Vista or 7 (I think). Also unless your receiver has discrete analog inputs for each of the 6 or 8 audio channels.
Like home theater. You'd have a receiver powering speakers, and you'd run all your audio into that--TV, radio, CD player, DVD, Blu-ray, PC. You can send audio from a PC to a receiver through the SPDIF (digital audio) out on the back of your computer. There are two flavors of SPDIF: optical and coaxial.