CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

making full use of the multicores in workstation

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 13, 2011, 14:14
Default making full use of the multicores in workstation
  #1
Senior Member
 
Hassan
Join Date: Apr 2009
Posts: 106
Rep Power: 17
HaKu is on a distinguished road
Hey All

i have multicore workstation and i want that my fortran code use all the processors in the system.

usually when i run the code it only uses 2 cores.. i know tht one thing is to do the parallel coding but i dont know bout tht a thing so tht option is out of picture..

can any thing be done in the setting of the workstation before running so atleast it uses 4 or 6 cores if not all ( i mean ayway to fool the workstation)..or nything be done to the hardware .

the main aim is tht serial code use more cores without parallel coding..

take care and all the best....
HaKu is offline   Reply With Quote

Old   July 13, 2011, 23:21
Default
  #2
Senior Member
 
Julien de Charentenay
Join Date: Jun 2009
Location: Australia
Posts: 231
Rep Power: 18
julien.decharentenay is on a distinguished road
Send a message via Skype™ to julien.decharentenay
Hi Hassan,

I believe that there are a number of compiler that auto-parallelises loop (see http://www.absoft.com/Absoft_Linux_Compiler.htm for an example).

From experience, the compilation is straightforward: need to recompile everything with the appropriate flag. I don't remember what needs to be done when you run the job, but there is probably something to be done. The performance gains and flexibility is far from optimum.

Good luck.
Julien
__________________
---
Julien de Charentenay
julien.decharentenay is offline   Reply With Quote

Old   July 25, 2011, 21:44
Default
  #3
Member
 
Join Date: Jul 2011
Location: US
Posts: 39
Rep Power: 15
Docfreezzzz is on a distinguished road
You are not going to be able to utilize more than one core for computation unless you utilize parallel/threaded programming techniques. It is likely what you are seeing is your code and then some background process using one core each. Compilers generally do not generate binaries automatically parallel in that sense. One easy option is OpenMP but you are likely to see very poor scaling past two cores unless you do some very fancy mutex locking, etc. Nothing is free my friend. Good luck
Docfreezzzz is offline   Reply With Quote

Old   July 26, 2011, 04:58
Default
  #4
Senior Member
 
cfdnewbie
Join Date: Mar 2010
Posts: 557
Rep Power: 20
cfdnewbie is on a distinguished road
Quote:
Originally Posted by HaKu View Post
Hey All

i have multicore workstation and i want that my fortran code use all the processors in the system.

usually when i run the code it only uses 2 cores.. i know tht one thing is to do the parallel coding but i dont know bout tht a thing so tht option is out of picture..

can any thing be done in the setting of the workstation before running so atleast it uses 4 or 6 cores if not all ( i mean ayway to fool the workstation)..or nything be done to the hardware .

the main aim is tht serial code use more cores without parallel coding..

take care and all the best....
Hello,
I would still seriously encourage you to try a simple approach to parallelization, like a shared memory (openmp) approach. Learning the basics should take less than half a day, and you will benefit from it greatly....


After all, what do you get from a automatic parallelization that has a bad efficiency?
Try real parallelization, you will benefit greatly from it.
If you need pointers to tutorials, let me know!

cheers
cfdnewbie is offline   Reply With Quote

Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[swak4Foam] swak4foam building problem GGerber OpenFOAM Community Contributions 54 April 24, 2015 17:02
OpenFOAM on MinGW crosscompiler hosted on Linux allenzhao OpenFOAM Installation 127 January 30, 2009 20:08
DxFoam reader update hjasak OpenFOAM Post-Processing 69 April 24, 2008 02:24
Errors running allwmake in OpenFOAM141dev with WM_COMPILE_OPTION%3ddebug unoder OpenFOAM Installation 11 January 30, 2008 21:30
DecomposePar links against liblamso0 with OpenMPI jens_klostermann OpenFOAM Bugs 11 June 28, 2007 18:51


All times are GMT -4. The time now is 04:50.