A quick question, I've currently got some Creative 2.1 speakers, running off the Motherboard (Asus P8Z77 if it makes any difference). Is it worth investing in a sound card (be it a cheap one, or expensive)?
Unless you specifically want a big surround setup (which some MB cards support to an extent anyway) or you need ASIO then there's no point upgrading the soundcard. As @Grayfox says you're not exceeding the physical capacity of the current equipment.