nwchem memory usage


Click here for full thread
Clicked A Few Times
I am trying to do ccsd(t) calculations. i am somehow confused by the amount of the memory usage by nwchem. There are several different types of ga errors that I are presumably all due to the allocation of memory. I managed to come up with a set of memory parameters that seem to solve some of the issues but the total amount of memory consumed is still too large and it seemed strange.

When I looked at the memory usage on the compute node, I see that one of the process is using 32gb of memory and each of the others uses less than 3gb. Why there is such a huge difference between the memory used by a single process and all the rest of the processes on a given node? It is the same case for all the compute nodes.

Are there a set of simple rules that one can follow to estimate the amount of memory the calculation may need for ccsd and ccsd(t) calculations? I am mostly doing it by trial and error, based on previous experiences and it is not a straight forward task.

Are there options to use disk for some of the ga arrays in memory? If there are such options, how much slower the calculation could be on a ballpark estimate?

Here are the parameters that I used for the calculation.

export MA_USE_ARMCI_MEM="T"
export ARMCI_DEFAULT_SHMMAX=16384
unset MA_USE_ARMCI_MEM

memory global 2400 mb stack 800 mb heap 100 mb noverify


Here is the input file for the calculation.

Thank you!

Zhiyong

charge +1
ecce_print ecce.out 

#memory global 1000 mb stack 1200 mb heap 100 mb noverify
memory global 2400 mb stack 800 mb heap 100 mb noverify

geometry units bohr
 C                  2.78171600   -0.63080200   -1.39802500
 C                  2.96181200    0.68784500   -0.94262000
 C                  2.98636200    0.95555600    0.43245500
 C                  2.80821600   -0.09039100    1.35495100
 C                  2.65228600   -1.41129000    0.89908600
 C                  2.64577100   -1.68183100   -0.47780500
 H                  2.78509900   -0.84090600   -2.46474900
 H                  3.10222400    1.49408700   -1.65769700
 H                  3.15055900    1.96884700    0.78769300
 H                  2.83426000    0.11481100    2.42223500
 H                  2.55716900   -2.22166500    1.61690800
 H                  2.54420300   -2.70322600   -0.83335700
 C                  0.19774400   -0.02998600   -0.38189100
 H                  0.91326900   -0.11491100    0.45619700
 O                 -0.52663200    0.05914400   -1.24583200
 C                 -2.07982100    2.63063700   -0.79692500
 C                 -0.80824000    3.14906100   -1.09100900
 C                  0.22115900    3.05290400   -0.14750900
 C                 -0.02016300    2.43694700    1.09261300
 C                 -1.29587400    1.93084700    1.39095700
 C                 -2.32539200    2.03161300    0.44581600
 H                 -2.88376200    2.72371000   -1.52224200
 H                 -0.63011200    3.64244200   -2.04275300
 H                  1.19532000    3.48502600   -0.36121900
 H                  0.76292400    2.40266900    1.84634000
 H                 -1.49049500    1.49956700    2.36953000
 H                 -3.32031100    1.66567500    0.68334800
 C                 -1.16143800   -3.02968600   -0.82900200
 C                 -0.49302300   -2.84716300    0.38825000
 C                 -1.03170000   -1.99334600    1.36802500
 C                 -2.25220100   -1.34218700    1.13259200
 C                 -2.91663600   -1.52009900   -0.08721800
 C                 -2.36539400   -2.35280500   -1.07279300
 H                 -0.75798200   -3.70847200   -1.57581100
 H                  0.41445200   -3.40605900    0.59767300
 H                 -0.53441700   -1.88671300    2.33029900
 H                 -2.69789800   -0.72904900    1.91023600
 H                 -3.87016200   -1.02990500   -0.26454500
 H                 -2.89238900   -2.50403500   -2.01111300
end


basis spherical
  O library 6-311++g** 
  H library 6-311++g** 
  C library 6-311++g** 
end

scf
# rohf
 singlet
end

#ccsd
#freeze atomic
#maxiter 20
#thresh 1e-6
#nodisk
#end

tce
#nodisk
io ga
ccsd(t)
2eorb
2emet 13
tilesize 20
end

#tce
#ccsd(t)
#maxiter 60
#diis 3
#thresh 1.e-6
#2eorb
#2emet 3
#attilesize 40
#tilesize 8
#freeze core atomic
#end

task tce energy