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<DIV><FONT face=Arial size=2>Dear Rémi and TRNSYS users,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>We recently did some experimenting with a dual-core
processor. Our aim was actually to find out if the hard disk writing of a
computer could be saturated by large TRNSYS outputs and thus become a
bottle-neck in simulations with big output files (and it seems like not easily
with standard modern computers).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>But...</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>To benefit from a dual core processor a program
must be multi-tasking, i.e. it must create multiple threads for the operating
system (OS) which the OS can then run in parallel. TRNSYS does not create
multiple threads, so if you are running only one simulation on a dual core
processor, it will run just as fast as if you would run it on a single core.
</FONT><FONT face=Arial size=2>However, you can run two TRNSYS simulations
simultaneously, and the OS will then run each simulation on its own
core. This means that you can run e.g. two parametric studies (or
divide one into two) at the same time and thus halve the needed time.
</FONT><FONT face=Arial size=2>BUT TAKE CARE: you must run two decks from
separate directories and see that also the output files end up in different
directories!!! (or change the names) Otherwise the simulations will write
to same files, the output data of the first started will be replaced by the
later started. </FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>I have no knowledge of how much you can benefit of
dual core processors when calling other programs from TRNSYS or with plugins.
But based on what is stated above, I'd say that you will benefit only, if the
other programs can do something useful <U>while</U> TRNSYS is solving. If TRNSYS
solver pauses for feedback from the other program and vice versa for each
iteration or time-step, you will probably have no notable perfomance boost. But,
for example, if the other program does data processing or writing to the
hard disk each time step <U>after</U> it has given feedback to TRNSYS then you
might benefit, as this will be done by the other core and TRNSYS can
continue a bit earlier. You have to try and see... </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Also, I don't know what happens with communication
between TRNSYS and the other programs if there are several instances running...
I have only tried with TRNSYS without external connections.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>
<DIV><FONT face=Arial size=2>I'd also be very interested to hear if other people
have more experience on this.</FONT></DIV></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>What comes to RAM, you should check how much you
are using with current simulations. You can do that with the windows performance
monitor by checking how much RAM is used and how much it changes when you start
a simulation. Additional RAM will only help if the OS is writing to the paging
file (virtual memory on hard disk) <U>while</U> you are running the simulation.
1GB for the computer should be more than enough, but it depends of course on
what other programs and system processes are running simultaneously...
TRNSYS does not eat memory as e.g. FEM/CFD does.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>What comes to processor speeds, the sim time should
be somewhat directly proportional to processor speed, so faster is better. That
is, if there are no other bottle-necks on the motherboard (bus
speeds, cache etc.). Usually in good quality commercial computers (or built by
experts) there should be no problems with processor not being optimized with
motherboard. (but changing a processor to your existing motherboard is another
thing...)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Hope that helps at least as a starting
point...</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Cheers</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial
size=2>-----------------------------------------------------------------------------<BR>Janne
Paavilainen <BR>MSc, PhD student<BR>Researcher in Energy and Environmental
engineering<BR>-----------------------------------------------------------------------------<BR>Solar
Energy Research Center SERC<BR>Dalarna University College<BR>SE-781 88
Borlänge<BR>Sweden<BR>-----------------------------------------------------------------------------<BR>tel
+46 (0)23 778728<BR>fax +46 (0)23 778701<BR>e-mail: <A
href="mailto:jip@du.se">jip@du.se</A><BR>-----------------------------------------------------------------------------<BR><A
href="http://www.du.se">www.du.se</A><BR><A
href="http://www.serc.se">www.serc.se</A><BR><A
href="http://www.eses.org">www.eses.org</A><BR><A
href="http://www.uni-kassel.de/fb15/ite/solar/solnet/">www.uni-kassel.de/fb15/ite/solar/solnet/</A><BR>-----------------------------------------------------------------------------<BR></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=remi.charron@nrcan-rncan.gc.ca
href="mailto:remi.charron@nrcan-rncan.gc.ca">Charron, Rémi</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=trnsys-users@engr.wisc.edu
href="mailto:trnsys-users@engr.wisc.edu">trnsys-users@engr.wisc.edu</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, November 10, 2006 6:43
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [TRNSYS-users] Quicker
processing speeds?</DIV>
<DIV><BR></DIV><!-- Converted from text/rtf format --><BR>
<P><FONT face=Arial size=2>Hello,</FONT> <BR><FONT face=Arial size=2>I am
currently running TRNSYS with using a computer with a 3.2 GHz prcoessor with
512 MB of RAM. It takes approximately 100 seconds to run a
simulation. This is a reasonable amount of time, except that I am
running TRNSYS with an optimisation program and am requiring to perform
thousands of TRNSYS simulations per run. I am thinking of getting a
quicker computer or workstation to help speed TRNSYS up. Has anyone had
experience running TRNSYS using duel core processors or other high performance
computers or workstations? If so, what have been your experiences?
Can the computation time be significantly reduced with the use of a more
powerful computer?</FONT></P>
<P><FONT face=Arial size=2>Thanks,</FONT> </P>
<P><FONT face=Arial size=2>Rémi Charron</FONT> <BR><FONT face=Arial
size=2>Research Officer</FONT> <BR><FONT face=Arial size=2>Photovoltaic and
Hybrid System Program</FONT> <BR><FONT face=Arial size=2>CANMET Energy
Technology Centre</FONT> <BR><FONT face=Arial size=2>1615 Lionel-Boulet Blvd,
P.O. Box 4800, J3X 1S6</FONT> <BR><FONT face=Arial size=2>Varennes,
Quebec</FONT> <BR><FONT face=Arial size=2>Tel: (450) 652-7948, Fax: (450)
652-5177</FONT> <BR><A href="http://cetc-varennes.nrcan.gc.ca"><U><FONT
face=Arial color=#0000ff
size=2>http://cetc-varennes.nrcan.gc.ca</FONT></U></A> </P>
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