I'm using a 1.4Ghz Athlon Thunderbird with about 500 files. The files are contained in a directory structure of:
D:\music\mp3\<artist>\<album>\filename

And I told it to findfile *.* on D:\music\mp3 It loads very slowly. Especially since it doesn't just display the name, it reads the ID3 information (not using mIRC's built in ID3 functions) and outputs that to the list as well. The list is an MDX header based listview. It takes anywhere from 10-15 seconds to load.