Speed of Mapped Drives Versus UNC References

We are benchmarking some file servers, and in the course of doing this I
discovered that expanding folders from a mapped drive letter is MUCH faster
than from a full UNC path. So if you have mapped \\server1\share1 as f:\,
expanding the folders on F: might take 1/4 to 1/2 of a second per folder
expansion, whereas the identical operations on the identical share done
through a shortcut to the full UNC path in Network Neighborhood will take
1.5 to 2 second *per folder expansion*. That's a really noticeable
difference over the course of a lot of file system browsing.

What accounts for this difference? Is the mapping to a local drive letter
removing the need to perform some additional authentication steps?

--
Will




Will