One major problem with implementing something like that (apart from memory constraints) is that the playlist is generated and saved when the playlist is selected. We need to look further ahead than the next tune in order for the caching to work properly, and to ensure that playlists carry on properly after power off/on again.

The memory issue is all to do with keeping the disk spun down - we mlock into memory so that unix doesn't try and access the disk when we're not expecting it.

Hugo