I am not really an audiophile, but I do appreciate good quality sound and would really want a sound card that could take load off of CPU for audio processing. I hope to not spend more than 70 dollars on a card, and I would like to hear your thoughts on the card also.
Onboard audio will not slow anything down, and most modern boards sound great if ask me. I have my audio set to 24bit 192000hz, I play guitar/bass in the line in and I found that 19200hz seemed to give a more of a crystal clear sound than 96000hz. This is on the ASRock 970 Extreme3. Adding a sound card wont improve anything, these newer CPU's can be used at 100% and still play HD audio at the same time without skipping a beat. I OC a lot, and run prime95 for a few hours and play music at the same time and once I recorded a track with it running, so I mean it wont effect performance.