Using FILE_FLAG_NO_BUFFERING will return noticeable speed gain?

Posted by 9dan on Stack Overflow See other posts from Stack Overflow or by 9dan
Published on 2011-01-01T17:49:36Z Indexed on 2011/01/01 17:54 UTC
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Performance

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winapi

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file-io

Recently noticed detail description of FILE_FLAG_NO_BUFFERING flag in MSDN, and read several Google search results about unbuffered I/O in Windows.

http://msdn.microsoft.com/en-us/library/aa363858(v=vs.85).aspx

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.

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?

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