Please consider looking at this node of mine from a few months ago (and at the thread that it's part of, too). The original question there was similar to yours, I think: someone wanted to be able to check a directory tree at regular intervals to locate all the paths and files that had been added since the preceding check.

One of the points made there was that using the GNU "find" command with backticks or system() was a lot faster than File::Find on big file spaces covering many thousands of files.

Another point was that, if you're doing this sort of checking at intervals, save listings of files (and mod times, if necessary) in each directory; then the next time you check, use "-newer list.file" to locate files more recent than the listing created during the last check.