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Serial version ran faster than parallel version in the sub_string_finder example

m_enayah1
Beginner
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Hi,

I'm just about to start in intel TBB. When i try to run the example sub_string_finder provided along with TBB 2.0 installation. I will get this result !!!

Done building string.
Done with serial version.
Done with parallel version.
Done validating results.
Serial version ran in 15.3412 seconds
Parallel version ran in 20.1178 seconds
Resulting in a speedup of 0.762569
Press any key to continue

There is something wrong here. I use VS2003 with Intel Pentium 4 3.07 Hz CPU with TBB 2.0 i was installing TBB 1.1 before and i update it to TBB 2.0

I will get a warning during complilation:

icl command line warning #10121: overriding '/Qvc8' with '/Qvc7.1'


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TimP
Honored Contributor III
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/Qvc7.1 is right for VS2003.
How does the parallel performance vary with HyperThreading on/off? If the example was written for multi-core, it may not be surprising if parallel does not improve performance, even with HyperThreading enabled.
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