CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > SU2

Large memory usage for steady simulation

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 15, 2020, 11:58
Default Large memory usage for steady simulation
  #1
New Member
 
Join Date: Aug 2019
Location: London
Posts: 9
Rep Power: 7
Wenqiang is on a distinguished road
Hi,


I am using SU2 to simulate a simple geometry, an 3D intake with far field boundary. The mesh is fully structured which has 1.5 million points. The simulation is pure aerodynamics without any adjoint simulation. When I was running this steady case, the RAM usage is 11.5GB (from system monitor in Ubuntu). When I tried another mesh with 4 million points, my system directly kills it as I guess it needs more than 32GB RAM.



I also tried a test case from SU2 tutorial ..../compressible_flow/Unsteady_NACA0012, this mesh has 14576 points, and the RAM usage on my desktop is about 77MB. If the RAM is proportional to the number of mesh points, a 1.5million mesh will need 8GB.



So I want to ask if anyone tried the mesh larger than 1million? What is the typical RAM usage? Is 10GB the normal RAM requirement for a 1 million mesh? I can provide my .cfg file if needed, but it is almost the same with that used for Unsteady_NACA0012, nothing special..... Any information or suggestions are welcome, thanks.



all the best,
Wenqiang
Wenqiang is offline   Reply With Quote

Old   May 15, 2020, 12:23
Default
  #2
pcg
Senior Member
 
Pedro Gomes
Join Date: Dec 2017
Posts: 466
Rep Power: 14
pcg is on a distinguished road
Hi,
With a 3D RANS problem on a hex dominant mesh with multigrid, the develop branch uses about 6.5GB per million nodes with the following linear solver options:
LINEAR_SOLVER_PREC= LU_SGS
DEFORM_LINEAR_SOLVER_PREC= JACOBI

If you use the ILU preconditioner this will go up to about 8.2GB per million nodes.
Unstructured grids will use more memory as in general each node will have more neighbors.

Be careful not to specify a large number of linear solver iterations when using FGMRES, each extra iteration costs about 80 MB per million nodes.

Cheers,
Pedro
pcg is offline   Reply With Quote

Old   May 15, 2020, 14:40
Default
  #3
New Member
 
Join Date: Aug 2019
Location: London
Posts: 9
Rep Power: 7
Wenqiang is on a distinguished road
Dear Pedro,


Thank you for your quick reply. Let me give it a try.


best,
Wenqiang
Wenqiang 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
independence in Large EDDy simulation medaouarwalid Main CFD Forum 1 June 30, 2017 15:41
GPU simulation Fluent out of memory xab Hardware 2 January 12, 2017 06:21
Decreasing the memory RAM usage of Fluent Rui_27 FLUENT 0 July 10, 2015 06:18
Error memory allocation on heat exchanger simulation air_fun CFX 15 November 4, 2013 09:54
Large Eddy Simulation with too high Mach number Roland R CFX 4 November 25, 2010 17:43


All times are GMT -4. The time now is 23:47.