I just finished installing GR 3 yesterday, plugged in and got lots of noise on some settings. I haven't had trime to figure it out yet. My PC initally had a Realtech souncard but I bought an M Audio Audiophile 192 a few years ago and it was the best thing I did for overall recording. I'm sure their are better (and more expensive) ways to eliminate problems with latency and such, but for my home studio, It made a major difference.
I am not a pro and have to hack my way thru Sonar 8.5 and digital recording in general. For home use, the soundcard made all the difference.