CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

OpenFOAM version 1.6 details

Register Blogs Members List Search Today's Posts Mark Forums Read

Like Tree6Likes

Reply
 
LinkBack Thread Tools Display Modes
Old   August 25, 2009, 08:38
Default
  #41
Senior Member
 
Sandy Lee
Join Date: Mar 2009
Posts: 207
Rep Power: 9
sandy is on a distinguished road
Thank you a lot, Alberto. In OpenFOAM, BICCG is diagonal ILU preconditioned BiCG solver, so it can be used to solve an asymmetrical or symmetrical matrix.

Last edited by sandy; August 25, 2009 at 10:03.
sandy is offline   Reply With Quote

Old   August 25, 2009, 23:44
Default
  #42
Senior Member
 
lakeat's Avatar
 
Daniel WEI (老魏)
Join Date: Mar 2009
Location: South Bend, IN, USA
Posts: 688
Blog Entries: 9
Rep Power: 12
lakeat is on a distinguished road
Send a message via Skype™ to lakeat
FYI, some updates.

1. I failed to use PGI compiler to recompile the OpenFOAM, lots of errors. And ICC, I failed again, something strange wrong.

My system info: 64 bits AMD Opteron(tm) 8347HE 1900MHz, InfiniBand

So, Henry said b4 he did not gain much using Icc over Gcc. I have no idea about this, anyway, I have recompiled the newest version of Gcc for now.

2. About Scotch, sorry for the misleading, I just read the "New Features" on the official website of OpenCFD, and it claims metis will be replaced with Scotch in the next release.

3. A question,
If mpi implementation is compiled with compilers other than Gnu-Gcc, but OpenFOAM is compiled with Gcc,
and,
If they are both compiled with Gnu-Gcc,
Which combination is faster?
I asked bcoz, the system mpi implementation (openmpi) is not compiled by Gnu-Gcc, but PGI's compiler.

4. i have problem installing mvapich2 which is designed for infiniband. Bcoz, several days before, the simulation of combination openmpi+OpenFOAM (both are compiled with Gcc) was so slow that I want to shoot somebody. So now I want to have a try of mpich2+openfoam (both are compiled with Gcc).

My team does not have a CFD background, I hope I could stop messing about and graduate as early as possible.
__________________
~
Daniel WEI
-------------
NatHaz Modeling Laboratory
Department of Civil & Environmental Engineering & Earth Sciences
University of Notre Dame, USA
Email || My Personal CFD Blog
lakeat is offline   Reply With Quote

Old   August 26, 2009, 21:47
Default
  #43
Senior Member
 
lakeat's Avatar
 
Daniel WEI (老魏)
Join Date: Mar 2009
Location: South Bend, IN, USA
Posts: 688
Blog Entries: 9
Rep Power: 12
lakeat is on a distinguished road
Send a message via Skype™ to lakeat
Some Updates.
  1. mvapich and mvapich2 implementation failed.
  2. starting mpich2 failed, {mpd &, mpirun -machinefile $PWD/nodelist -np ...} didn't work.
  3. I compiled new version mpich-1.2.7p1, and it works now.
  4. I compared the speedup with different number of processors, but the speedup is far from linear, using 8 processors, the speedup is only about 3.5, and using 16 processors, the speedup is only 9.1, ie. a sublinear speedup of 43.1%. That's very bad, isn't it?
    If you want to know further results (some figures and tables), please email me and let me know. lakeat@gmail.com
  5. Simon's comment is of great value, much appreciated.
    Quote:
    In my case, it made a huge difference (note I'm using 1.5-dev). With the pre-compiled version, there was a small speedup at 4 or 8 processors, but far from a linear speed. When using more than 8 processors, it was slower and the clocktime was much larger than the cpu time. After being compiled on the supercomputer with the Intel compiler, the speedup is much better.
  6. Next step, I am going to compare my compiled mpich and openmpi, and then using the same number of processors but on different nodes.

And thanks to everyone.
__________________
~
Daniel WEI
-------------
NatHaz Modeling Laboratory
Department of Civil & Environmental Engineering & Earth Sciences
University of Notre Dame, USA
Email || My Personal CFD Blog

Last edited by lakeat; August 27, 2009 at 02:14.
lakeat is offline   Reply With Quote

Reply

Thread Tools
Display Modes

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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Superlinear speedup in OpenFOAM 13 msrinath80 OpenFOAM Running, Solving & CFD 18 March 3, 2015 06:36
OpenFOAM - Validation of Results Ahmed OpenFOAM Running, Solving & CFD 9 June 22, 2011 18:59
OpenFOAM Version 1.6 Released opencfd OpenFOAM Announcements from ESI-OpenCFD 0 July 27, 2009 17:55
user subroutine error CFDUSER CFX 2 December 9, 2006 07:31
user defined function cfduser CFX 0 April 29, 2006 10:58


All times are GMT -4. The time now is 11:56.