why my OpenMP C++ code is slower than a serial code?

why my OpenMP C++ code is slower than a serial code?

References

Reference NO 1

http://stackoverflow.com/questions/15206176/why-my-openmp-c-code-is-slower-than-a-serial-code

Reference NO 2

http://stackoverflow.com/questions/17417444/c-openmp-slower-than-serial-with-default-thread-count

Reference NO 3

http://software.intel.com/en-us/articles/performance-obstacles-for-threading-how-do-they-affect-openmp-code

Reference NO 4

http://en.wikipedia.org/wiki/OpenMP

Reference NO 5

http://openmp.org/forum/viewtopic.php?f=3&t=1150

Reference NO 6

http://social.msdn.microsoft.com/Forums/vstudio/en-US/528479c8-fb70-4b05-83ce-7a552fd49895/action?threadDisplayName=performance-problem-using-openmp-with-visual-c-2010

Reference NO 7

#EANF#

Reference NO 8

#EANF#