move large files

if I check move large files will it always do it or must I always go to option and make the choice?

It took a very long time the first time I asked to move large files. It was on a laptop / 1.5 gig ram / 60 gig HD (10 gig remaining

Should I always choose to move large files to the end or choose which files to move. If I move my Contact Manager database to the end, it will always need to search the end. I use my CM each day and all day.

Also when I moved them to the end there was a large hole in the middle of the HD. IS that OK?