How to Set Size of Global Array?

Just Got Here

1:40:20 PM PDT - Wed, Mar 29th 2017

Hi all,

I got the following GA error when doing EOMEA-CCSD calculation. It seems my available GA space is not large enough. Is there a way to change the size of the available GA space?

Thanks,
Yuan

Parallel file system coherency ......... OK



Fock matrix recomputed

1-e file size   =           147456

1-e file name   = ./b4cho-6s6p6d.f1   

Cpu & wall time / sec           39.5           39.5

4-electron integrals stored in orbital form

1: WARNING:armci_set_mem_offset: offset changed 613451268096 to 613450219520
2: WARNING:armci_set_mem_offset: offset changed 289350471680 to 289349423104
3: WARNING:armci_set_mem_offset: offset changed 449792598016 to 449791549440
4: WARNING:armci_set_mem_offset: offset changed 752342880256 to 752341831680
5: WARNING:armci_set_mem_offset: offset changed -72531296256 to -72532344832
6: WARNING:armci_set_mem_offset: offset changed 70680068096 to 70679019520

v2    file size   =       3160356621

4-index algorithm nr.  15 is used

imaxsize =       40

imaxsize ichop =        0

 available GA memory             7324899752  bytes

 available GA memory             7324920008  bytes

tce_gacreate: failed ga_create size/nproc bytes          8557730064

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

Forum Regular

4:53:25 AM PDT - Thu, Mar 30th 2017
See http://nwchemgit.github.io/index.php/Release66:Top-level#MEMORY and http://nwchemgit.github.io/index.php/Release66:TCE#Memory_considerations

Just Got Here

7:07:15 AM PDT - Thu, Mar 30th 2017
Quote:Sean Mar 30th 4:53 am See http://nwchemgit.github.io/index.php/Release66:Top-level#MEMORY and http://nwchemgit.github.io/index.php/Release66:TCE#Memory_considerations Thanks. Still don't understand where global array is. Does it use the space in "global" when I'm allocating the memory, or somewhere else? So when I'm setting memory like "memory stack heap global ** mb", am I telling the program some information about global array allocation? From the quote above, how to allocate global array seems depending on the machines architecture --- distributed memory or shared memory.

Forum Regular

7:45:27 AM PDT - Thu, Mar 30th 2017
Yes, in the memory allocation global refers to the memory available to global arrays. So an allocation such as memory stack 500 mb heap 100 mb global 1300 mb would allocate 1300 MB to global arrays. As far as the dependence on machine architecture, you do not need to worry about it. If you are on a shared memory machine, then you will get what you specify. If you are on a distributed memory machine, the code will essentially ignore the partitioning between memory segments (the total memory allocated is all that is really important in this case) and global arrays can use as much memory as is not in use by stack/heap.

Just Got Here

8:50:16 PM PDT - Thu, Mar 30th 2017
Thanks!

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