Reading/Writing to a file, fastest method?

I have a series of arrays (string and integers) that I need to write to a file (text file for now). I used the My.Computer.FileSystem.WriteAllText (with append) while looping through the arrays approach and it works fine, but it is a little on the slow side. Is there a better way?

Is there a way to dump/retrieve the contents of an array to a binary file?

Rick