[overture] Re: 3d cgins memory usage
- From: Joel Guerrero <joegi.geo@xxxxxxxxx>
- To: overture@xxxxxxxxxxxxx
- Date: Thu, 26 Feb 2009 01:57:53 -0800 (PST)
Hi Bill,
According to you, which iterative solver is best to use, the one that comes
with overture or petsc?. I will try to run my problem in a clean overture
instalation, to check if I still have this memory problem.
Regards,
Joel
----- Original Message ----
From: Bill Henshaw <henshaw@xxxxxxxx>
To: overture@xxxxxxxxxxxxx
Sent: Thursday, February 26, 2009 6:06:07 AM
Subject: [overture] Re: 3d cgins memory usage
Hi,
Just a note that usually all the memory is used up
by the pressure solver and implicit solver, i.e. PETSc
if that is what you are using. You can reduce the PETSc memory
use by decreasing the number of ILU levels etc. and/or
changing the iteration from bi-CG-stab (default) at the
cost of taking longer to solve.
Also note that if you run with gdb then you can
see who is allocating memory when the heap error
occurs.
...Bill
#DOMINIC DENVER JOHN CHANDAR# wrote:
> Hi Joel,
>
> Generally I have a total of 5 grids.
> 1 - An outer cartesian (which forms something like a far-field)
> 2 - An inner cartesian (all sides interpolation )
> 3 - Wing grid
> 4 - Wing cap (South)
> 5 - Wing cap (North)
>
> For Grid (1),(2) I use explicit.
> Yes I use artificial diffusion. Typical values 1.0.. For nu O(10^-5). I
> observe a change in Cd when I change this
> Parameter.
> The grid sizes that I usually try is around 0.9M-1.3M points. Right now,
> I have a grid with 3M points and I will be
> Running it shortly. Will let you know if it crashes...
> Regards,
> Dominic
>
>
>
> -----Original Message-----
> From: overture-bounce@xxxxxxxxxxxxx
> [mailto:overture-bounce@xxxxxxxxxxxxx] On Behalf Of Joel Guerrero
> Sent: Wednesday, February 25, 2009 11:35 PM
> To: overture@xxxxxxxxxxxxx
> Subject: [overture] Re: 3d cgins error
>
>
> Hi Dominic,
>
> Regarding this memory issue, I wonder how are you running your
> simulations, are you fully explicit? are you using artificial
> difussion?. Im trying to fix my memory problem, but the solver always
> crash above 1.3M point. I checked and the memory is available. What is
> the max grid size that you have been able to sovle?
>
> Cheers,
> Joel
>
>
>
> ----- Original Message ----
> From: #DOMINIC DENVER JOHN CHANDAR# <DOMI0002@xxxxxxxxxx>
> To: overture@xxxxxxxxxxxxx
> Sent: Monday, February 2, 2009 3:31:17 PM
> Subject: [overture] Re: 3d cgins error
>
> Do a 'top' in your command prompt to see if the memory used is
> increasing with time step. Once it happened that I added a routine that
> resulted in a similar situation.
>
> Dominic
>
> -----Original Message-----
> From: overture-bounce@xxxxxxxxxxxxx
> [mailto:overture-bounce@xxxxxxxxxxxxx] On Behalf Of Joel Guerrero
> Sent: Monday, February 02, 2009 10:27 PM
> To: overture@xxxxxxxxxxxxx
> Subject: [overture] Re: 3d cgins error
>
> Hi, It seems estrange, I am running on a machine with 8 gigs of memory
> so in theory I shouldn't have memory problems.
>
> jg
>
>
>
> ----- Original Message ----
> From: #DOMINIC DENVER JOHN CHANDAR# <DOMI0002@xxxxxxxxxx>
> To: overture@xxxxxxxxxxxxx
> Sent: Monday, February 2, 2009 3:24:22 PM
> Subject: [overture] Re: 3d cgins error
>
> Hi Joel,
>
> I too get this error when there is not enough RAM available. This
> usually happens when you run a big test case like yours.
> For 1.2M points, it generally uses ~ 4 GB of memory for me.
> Also, I have observed if you use all boundaries except the inflow as
> "outflow BC", the solution is unstable sometimes. I don't recall when
> this happens ( might be when the outer boundaries are quite close to the
> body ).
>
> Regards,
> Dominic
>
>
> -----Original Message-----
> From: overture-bounce@xxxxxxxxxxxxx
> [mailto:overture-bounce@xxxxxxxxxxxxx] On Behalf Of Joel Guerrero
> Sent: Monday, February 02, 2009 10:15 PM
> To: overture@xxxxxxxxxxxxx
> Subject: [overture] 3d cgins error
>
> Hi,
> I'm trying to run a moving 3d problem with cgins. Usually using a grid
> with less than a million points works fine, but when I use a grid with a
> little bit more than a million points (1.2m) I'm getting this error
>
> HEAP ERROR: Array_Data_Pointer == NULL in double* MDI_double_Allocate
> (Size = 77616929)!
> I am using one inflow bc and the rest of the bc are outflow, on the
> moving body I set noslip bc. Any idea what could be the problem?
>
>
> Regards,
>
> Joel
>
>
>
>
>
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