It will be plenty fast, and I can easily see a terabyte being needed.Right now Ive got 750 cdr's and 175 dvd's sitting here,plus 75 movies on one drive, plus a HD full of music, plus another drive just with my usual daily stuff on it I use all the time.Right now you run into issues with having a bunch of drives unless you run multiple systems, which is what Ive had to do.Going the SCSI route to eliminate the 4 drive only problem with IDE gets expensive real fast, its cheaper just to use bigger drives, and it keeps getting cheaper and cheaper.Using a PC as a multimedia entertainment center its quite easy to rack up lots of gigs of movies and music pretty quickly.Encoding a TV show on the fly into mpeg's means 2 gigs/hr, it adds up fast.