Mac OS X 10.3 or later automatically converts PostScript (.ps) or Encapsulated PostScript (.eps) files to PDF when viewing in Preview, Mail, or certain third-party applications. The conversion process typically takes a short period of time (depending on the complexity of the file), and may take longer for the first conversion within each user account. Any subsequent PostScript files viewed by the same user should be converted to PDF faster than the first time.
The conversion process may also be noticeably slower if the com.apple.psnormalizer files are removed from /Library/Caches.
A delay may be noticed the first time any user of the computer prints a PostScript file by dragging it onto the icon of a non-PostScript printer. However, there should be no additional delay the next time any user of the computer prints a PostScript file this way.