Extremely Slow Performance Zipping a Single Large File

Mar 7, 2013 at 2:23 PM
I'm trying to use the latest version of dotnetzip to zip up and password protect a single Sql Server backup file approximately 400 MB in size using the following code:

Using zip As New Ionic.Zip.ZipFile()
zip.Password = "Password"
zip.AddFile(filename)
zip.Save(filename + ".zip")
End Using

Nothing fancy. But it takes nearly forever for it to finish. I've played with various properties (setting ParallelDeflateThreshold to -1, trying different compression levels and methods, etc), but nothing seems to help.

Is anyone else having the same experience? Any ideas on how I can improve the performance?