title: Using FILE_FLAG_NO_BUFFERING will return noticeable speed gain?
body: <p>Recently noticed detail description of FILE_FLAG_NO_BUFFERING flag in MSDN, and read several Google search results about unbuffered I/O in Windows.</p>
  
  <p><a href="http://msdn.microsoft.com/en-us/library/aa363858(v=vs.85).aspx">http://msdn.microsoft.com/en-us/library/aa363858(v=vs.85).aspx</a></p>
  
  <p>I wondering now, is it really important to consider unbuffered option in file I/O programming? Because many programs use plain old C stream I/O or C++ iostream, I didn't gave any attention to FILE_FLAG_NO_BUFFERING flag before.</p>
  
  <p>Let's say we are developing photo explorer program like Picasa. If we implement unbuffered I/O, could thumbnail display speed show noticeable difference in ordinary users?</p>