Gigabyte motherboard audio problem

Greetings!

first of all sorry for my bad english and for opening a new thread.
my config(bought a couple of days ago):gigabyte ma78gm-s2h motherboard,amd x2 6000+,2Gb ram,and an old 160gb seagate ide hard drive(bought it 2 and a half years ago but never used it)
im using the integrated video and sound card.
recorded a video in doom 3 to show what is my problem:http://www.youtube.com/watch?v=6lF5hXw-ePU
i only tried 2 games, doom 3 and world of warcraft.the sound is skipping(or maybe its not the right word for ir) as you can hear in the video.
tried the 2 games on the lowest video config but the problem was still on.i installed the drivers from the motherboard's cd and from the gigaybyte homepage too.
if anyone of you can help i would appreciate that.

Mondoman has it - the big problem with gaming an on-board video chip is memory access/bandwidth; with a video card, the GPU has its' own high-speed channel to its' own RAM; it only uses 'shared' memory (accessible to the CPU) to transfer information, not to create the pixel mappings; with on-bord video (with a couple of exceptions - mostly aimed specifically at HTPCs) the GPU is using main memory, and the GPU/CPU cannot use it simultaneously, so the CPU is sitting on 'wait states' 'till the GPU gets done; buy a cheap nVidia card (if you'll be satisfied with not-so-high resolution) and your problem will go away...