High ram usage during solution on a moderate mesh about gdtk HOT 6 CLOSED

Hi Hilbert,

We have a few compile time flags you can try turning off to save some memory, depending on what you need, try some or all of the following:

MULTI_SPECIES_GAS=0
MULTI_T_GAS = 0
MHD=0
TURBULENCE=0

All of these are on by default but can be turned off when calling make. For example, to build e4shared, e4mpi, and e4zmpi without MHD or two temperature capability, you would do:

$ make WITH_MPI=1 WITH_COMPLEX_NUMBERS=1 MHD=0 MULTI_T_GAS=0 FLAVOUR=fast install

Let me know if you run into any trouble.

from gdtk.

Hi Nick,

I only just got around to testing your suggestion. It did save me a bit of RAM but nothing significant.
I am mainly interested since we are about to buy a couple new boxes and I want to make sure the boxes have enough RAM on board. Given the CPU count we are going after I am hopeful we can run 20-30M cell grids. What would you recommend RAM wise for such grids?

Cheers,
Hilbert

from gdtk.

That's disappointing.

I am planning to do some memory tuning at some point soon, so hopefully that will help. I guess if you can find 250 GB of RAM for your new boxes you'll be able to make 20M work, and possibly 30M once I can work on the memory.

Nick,

from gdtk.

HI Nick,

Thanks that Is roughly what I was thinking.

Hilbert,

from gdtk.

29ae23f should have improved this issue. Let me know if you notice any improvment.

from gdtk.

Just letting you know that on a 5.7M cell mesh that I have lying around the RAM usage went from 79.2 to 78.1 Gb, so roughly a 1 Gb improvement.

from gdtk.