bad results with two threads

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bad results with two threads

Postby Stefoo » Wed Dec 12, 2007 5:52 am

Hi, everyone! I use OpenMP for a project in the university. When I use two threads on P4 with HT there is no speed up, but on core 2 duo there is significant speed up. Can someone help me. I use in the project MPI, so I must test my project in the university lab where we have 10 PC with P4 HT. How can speed up my project on P4 HT?

Thank you
Stefoo
 

Re: bad results with two threads

Postby lfm » Wed Dec 12, 2007 7:58 am

HT only provides a hardware context for a thread, not a full extra core. So you won't see any speedup if your program needs lots of resources such as memory, cache, or floating point computation.
lfm
 
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Re: bad results with two threads

Postby Stefoo » Sat Dec 29, 2007 10:20 am

Thank you, lfm! I discussed the problem with my teacher. She gave me the same answer.


Last bumped by Anonymous on Sat Dec 29, 2007 10:20 am.
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