Will a dedicated sound-card decrease CPU load?

Solution 1:

Absolutely!

Check out this post over at guru3d.

Solution 2:

This is an old question, but it certainly deserves an answer.

Yes it most certainly will help. Motherboard mounted sound chips do not offer any type of AD/DA conversion capabilities, and even if they do they will be heavily laden with latency issues because of the way Windows works (if you are using Windows). In order to do sample conversions the work must be handed off to the CPU, which causes latency to build and that is when you get real anomalies appearing in your audio.

You will discover that there are also USB headsets, but these act precisely the way on-board conversion chips do. They move a program to the CPU which does the heavy lifting.

Interfaces, whether USB or Firewire, have actual AD/DA processors, as do the higher end audio cards. If, you want to play games, then you might also want to chose one of the more exceptional cards that offer 3D positioning.