How to empty/flush Windows READ disk cache in C#?

Question

If I am trying to determine the read speed of a drive, I can code a routine to write files to a filesystem and then read those files back. Unfortunately, this doesn\'t give

Answer 1

const int FILE_FLAG_NO_BUFFERING = 0x20000000;
return new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read,64 * 1024,
(FileOptions)FILE_FLAG_NO_BUFFERING | FileOptions.Asynchronous
& FileOptions.SequentialScan);