Some audio help - External sound card or not

[savagesam117]

I've got an Asus U7 sitting here, and i've got an asus Strix mobo. I'm just wanting to know what would sound best, i've got some tannoy speakers paired with a cambridge audio amp, nothing special. but will I notice a difference using the U7?

 

[savagesam117]

I use the speakers for general use, headphones when i'm gaming.

It's open I found it in my spares box, I totally forgot I owned it, i'll pop it in and see how it goes. Be rude not too.