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

running out of memory in Gambit, Help!!!

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

Reply
 
LinkBack Thread Tools Display Modes
Old   January 1, 2006, 20:49
Default running out of memory in Gambit, Help!!!
  #1
ahmet
Guest
 
Posts: n/a
Hi guys;

I am using Gambit on a supercomputer (unix) and running out of memory while meshing a 6 ft circular duct (6 inch. dia) with 0.1 inch. 'stairstep'.

I submitted a batch job specifying 4 CPUs (parallel) and 8gb of memory, however the process was killed after 7000 something seconds. Out of memory!!! (how come???).

The system technician told me that I probably underspecified number of CPUs and memory in Gambit (What???).

Anyone knows how to specify memory usage in Gambit (if there is any)?

Thanks in advance.

Ahmet
  Reply With Quote

Old   January 1, 2006, 20:58
Default Re: running out of memory in Gambit, Help!!!
  #2
ahmet
Guest
 
Posts: n/a
By the way, I specified the 4 cpus and 8gb memory outside gambit. The batch file I submitted is as follows.

-----------------------------

#PBS -N duct

#PBS -S /bin/tcsh

#PBS -j oe

#PBS -l cput=10:00:00

#PBS -l ncpus=4,mem=8gb

cd /scratch/a0u8545/060102

module load gambit

gambit -inp 6inch.jou

qstat -f $PBS_JOBID

-----------------------------
  Reply With Quote

Old   January 3, 2006, 11:44
Default Re: running out of memory in Gambit, Help!!!
  #3
Jason
Guest
 
Posts: n/a
Gambit doesn't run in parallel, no matter how many processors you define in your LSF (I'm assuming it's an LSF or some variant based on the input scripts... I use similar stuff here at work). And depending on how your LSF is set up, a single process is often limited to 2Gb of RAM. Some LSFs let you unset the per-process memory limit (The per-process memory limit is different from the memory allotted per processor... like when you're running 3 or 4 programs on your desktop at home... EACH of those programs is limited to a maximum RAM usage of 2Gb by the operating system no matter how much RAM is in the computer).

A quick estimate of your mesh size though... 6" diameter x 6' long pipe... that's a volume of ~2035in^3... a .1" hex mesh would result in about ~2million elements. You shouldn't be hitting a memory limits with that small a mesh. I've meshed 8 million tet elements with complicated geometry without any memory limits. I wonder if there's something going on in your Gambit journal that's causing the problem.

Good luck, Jason

  Reply With Quote

Old   January 4, 2006, 14:53
Default Re: running out of memory in Gambit, Help!!!
  #4
ahmet
Guest
 
Posts: n/a
Hi Jason,

First of all thanks for the information on the processor and the RAM. That means I need to deal with less variables.

The journal file should work ok because I tried it with simpler geometries.

I learned that there is a program variable that you can set the memory

"global..gambitmem"

However, I couldn't get it to work so far. Maybe I am typing it in wrong. It also said gambitmem is not defined.

The following link has the information on that if you are interested.

http://zsc.zcu.cz/sw/manuals/gambit/...htm#cr05010204

Thanks again.

Ahmet
  Reply With Quote

Old   August 8, 2009, 16:31
Default Need help
  #5
New Member
 
Akshayy Garg
Join Date: Aug 2009
Location: delhi, india
Posts: 6
Rep Power: 8
akshayygarg is on a distinguished road
HiI am running out of memory 2gb although i have ram of 4gb and space more than 40gb on disk. plz need help. program icrashin don again and again.Akshayy Garg
akshayygarg is offline   Reply With Quote

Old   August 10, 2009, 01:05
Default
  #6
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,992
Rep Power: 30
-mAx- will become famous soon enough
you are trying to mesh something which ask lot's of memory.
Decrease the mesh size, or split your domain
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   August 10, 2009, 01:22
Default Problem with Fine Volume Meshing in Gambit
  #7
New Member
 
Akshayy Garg
Join Date: Aug 2009
Location: delhi, india
Posts: 6
Rep Power: 8
akshayygarg is on a distinguished road
Hi

Thanks for the earlier reply. Actual problem is this.

I have two volumes:
Vol1. Cylindrical - 340mm dia and 600mm height
Vol2. Cubical - 200X200X0.3mm

100 volumes of Vol2 are kept in middle of Vol1. Now these 100 volumes are subtracted from Vol1. The new volume so formed has to be meshed using GAMBIT. But due to very fine volumes i am not able to do so.

Kindly Help.
Akshayy Garg
(IIT Delhi)
akshayygarg is offline   Reply With Quote

Old   August 10, 2009, 03:26
Default
  #8
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,992
Rep Power: 30
-mAx- will become famous soon enough
split your domain (by dividing it, you will mesh subvolumes which will ask less memory)
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   August 10, 2009, 07:51
Default
  #9
Member
 
Daniel Tanner
Join Date: Apr 2009
Posts: 54
Rep Power: 8
Daniel Tanner is on a distinguished road
Gambit is 32-bit and not parallelised. This means that a gambit process can access a theoretical maximum of 2^32 bits of RAM ~ 4Gb. However, these are limited by the platform you are using (Windows/Linux....) to ~2Gb. If you have memory issues: reduce mesh size, split mesh into smaller volumes or use TGrid (which is 64-bit).
Daniel Tanner is offline   Reply With Quote

Old   August 12, 2009, 03:08
Default
  #10
Super Moderator
 
-mAx-'s Avatar
 
Maxime Perelli
Join Date: Mar 2009
Location: Switzerland
Posts: 2,992
Rep Power: 30
-mAx- will become famous soon enough
but gambit for linux amd64, should be 64bit.
I assume it can handle more than 2GB, right?
__________________
In memory of my friend Hervé: CFD engineer & freerider
-mAx- is offline   Reply With Quote

Old   August 12, 2009, 03:41
Default
  #11
Member
 
Daniel Tanner
Join Date: Apr 2009
Posts: 54
Rep Power: 8
Daniel Tanner is on a distinguished road
Sorry, Max is right. I hadn't realised that the 64-bit version was available. However, the rest still holds. 32-bit => ~2 Gb but if you have access to a 64-bit computer you will not have any problems. If you are stuck with 32-bit then split domain, reduce mesh size.
Daniel Tanner is offline   Reply With Quote

Old   April 6, 2011, 13:05
Default
  #12
New Member
 
Geon-Hong Kim
Join Date: Feb 2010
Location: Ulsan, Republic of Korea
Posts: 27
Rep Power: 7
Geon-Hong is on a distinguished road
Jason/

Thanks. Your reply helps me to solve my problem.

Every time I meshing a 3D wing I encountered memory problem of GAMBIT, which was terminated due to excess of memory of 2GB.

It was totally journal file problem!

I removed the journal file and finally completed meshing the wing.
Geon-Hong is offline   Reply With Quote

Old   April 18, 2011, 03:29
Default Heeeeelp meeeee
  #13
New Member
 
Ghayoumi's Avatar
 
Ghayoumi
Join Date: Apr 2011
Posts: 4
Rep Power: 6
Ghayoumi is on a distinguished road
i have this problem too, but i can't solve it, please help me .....
please enlarge it ......
Ghayoumi is offline   Reply With Quote

Old   October 10, 2011, 11:36
Default i am confused of .
  #14
Senior Member
 
Emre G
Join Date: May 2011
Location: Turkey
Posts: 109
Rep Power: 6
emreg is on a distinguished road
i have these system specifications:
- i7 2600 intel 64x
- 8 gb ram
- 4 processors

I am trying to mesh a volume which has nearly 4-5 million cell. However suddenly i get a warning message "out of memory".

But on the another computer (2 gb ram, dual core) i can manage 4.5 million meshes in the same conditions.

Where is the problem?

Thanks
emreg is offline   Reply With Quote

Old   October 1, 2013, 14:52
Lightbulb Solve this problem
  #15
New Member
 
Ghayoumi's Avatar
 
Ghayoumi
Join Date: Apr 2011
Posts: 4
Rep Power: 6
Ghayoumi is on a distinguished road
Hi,
To solve this problem you must use a Linux version of gambit!
gambit is a Linux program originally.
Ghayoumi is offline   Reply With Quote

Old   October 1, 2013, 15:52
Default
  #16
Senior Member
 
Emre G
Join Date: May 2011
Location: Turkey
Posts: 109
Rep Power: 6
emreg is on a distinguished road
hi, how many cells can be meshed using Linux gambit?
It can be 10 million ?
emreg is offline   Reply With Quote

Old   October 2, 2013, 09:47
Default
  #17
Senior Member
 
ghost82's Avatar
 
Daniele
Join Date: Oct 2010
Location: Italy
Posts: 919
Rep Power: 15
ghost82 will become famous soon enough
Quote:
Originally Posted by emreg View Post
hi, how many cells can be meshed using Linux gambit?
It can be 10 million ?
I successfully meshed 8 million cells on the fly using gambit linux 64 bit (I used 32 gb of ram).

Daniele
ghost82 is offline   Reply With Quote

Old   October 2, 2013, 14:32
Default
  #18
Senior Member
 
Emre G
Join Date: May 2011
Location: Turkey
Posts: 109
Rep Power: 6
emreg is on a distinguished road
are you expressing that the meshing of 8 million on the one time (not sequently) is possible using linux ?
emreg is offline   Reply With Quote

Old   October 5, 2013, 05:23
Default
  #19
Far
Super Moderator
 
Far's Avatar
 
Sijal Ahmed Memon (turboenginner@gmail.com)
Join Date: Mar 2009
Location: Islamabad Pakistan
Posts: 3,971
Blog Entries: 6
Rep Power: 39
Far will become famous soon enoughFar will become famous soon enough
Send a message via Skype™ to Far
Quote:
Originally Posted by emreg View Post
are you expressing that the meshing of 8 million on the one time (not sequently) is possible using linux ?
Yes it is possible. Any how Tgrid and ICEM CFD are capable of handling of over 40 million mesh size on desktop computers...
Far is offline   Reply With Quote

Old   October 5, 2013, 06:01
Default
  #20
Senior Member
 
ghost82's Avatar
 
Daniele
Join Date: Oct 2010
Location: Italy
Posts: 919
Rep Power: 15
ghost82 will become famous soon enough
Quote:
Originally Posted by emreg View Post
are you expressing that the meshing of 8 million on the one time (not sequently) is possible using linux ?
Yes, that is what I wrote.
This is possible if you have enough ram, a linux 64 bit operating system and gambit 64 bit.

Daniele
ghost82 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
Please help me.. Out of memory İn gambit emreg ANSYS Meshing & Geometry 11 October 19, 2011 01:14
Problems with Gambit running on windows xp pro Carlos Ruiz FLUENT 1 February 27, 2009 06:04
In GAMBIT meshing, Out of Memory! ? Conan FLUENT 7 November 10, 2008 05:02
3d Gambit meshing shows out of memory tamjid FLUENT 3 September 27, 2008 01:01
Runing Out of memory in Gambit Akin FLUENT 6 February 10, 2005 16:32


All times are GMT -4. The time now is 20:52.