View Full Version : Optimizing programs for dual PC's ??

05-11-1997, 07:16 PM
Dear Biomch-L Readers,

I'd like to know if somebody knows what kind of C library we should use
to tune our programs for a dual-processors machine ?

The dealer of the machine told me that there is no need to tune
programs because Windows NT will take care of the multiprocessor

I think the dealer is partly right: indeed NT will increase the program
process using both processors, but it won't be tremendous (I read somewhere
the gain is about 20% for not tuned programs).

Now, if we really want to use both processors in a very effective way, we need
to tune our programs with special libraries and compilers.

I have some previous experience with a Unix based dual-processors system.
We performed some tests to compared programs compiled with and without special
libraries. The difference was huge!!

When asked, the compiler really take care of assigning each iteration
of a loop to a specific processor and analyse the program for parallelisation
and vectorisation (both parallel... and vector... are techniques used to
optimize programs in a multi-processor environnement).

Now, I am sure that a similar process MUST happen on a dual PC to take fully
advantage of both processors.

So, I repeat my question:

Are you aware of optimization techniques for a dual PC environnement using
a C or C++ compiler and special libraries? (I emailed my request to the
Microsoft support, but they are quite slow to answer!!)

Maybe is the above-mentioned dealer right (but it would surprised me!).
In that case, I'd like to know how NT can "look into" the binary code
of an executable file to assign the instructions in a parallel-like way ?

Thank you very much in advance for every answer!!
I'll post a summary of the answers.


Serge VAN SINT JAN, Ph.D. | phone: + 32 2 555 63 25 (office)
Dept. of Anatomy (CP 619) | + 32 2 555 63 76 (secretary)
University of Brussels | fax: + 32 2 555 63 78
808 Lennik Street | email: sintjans@ulb.ac.be
1070 Brussels - Belgium | WWW: http://homepages.ulb.ac.be/~sintjans