Im considering adding a slave hard drive on my computer. Of the 200gb orig hd only 178 was originally available. 8 was restore and 8.5 video memory. (Its a media center pc) I put 16 gigs on it as MP3s and want to add about 6x more. I beleive moving this 100 gigs off the main hd onto a slave would keep my computers operating speed from slowing down. I havnt experienced any noticable slowing yet but have had the problem before on a Celeron when it got close to filling up at 80gbs. The manufactorer (HP) claims the computer wont slow down with all these files on the hd but they didnt strike me as very knowledgable.