yes they can.

Remember that graphics cards and the whole issue of bandwidth on your mobo have a history, graphics cards have a tendency to want to hog bandwidth due to their intensive nature.

There are also issues related to

Drivers
Mobo compatibility
The programs you use
and the OS you use.

historicallt matrox are supposed to be the best at getting along with audio appz, mainly IMHO because they dont have bells and whistles on them, like cards such as ATI and nVIDIA.