[Wien] machines file and klist splitting

Fred Nastos nastos at physics.utoronto.ca
Fri Oct 15 23:35:42 CEST 2004


I setup a .machines file, and I'm suspicious of the how the klist is being 
split.  It seems non-optimal, so I suspect I did something wrong.

The machine has two dual cpu slave nodes, and one masternode.
Actually, the machine has many nodes, but let's assume I am using
only using two nodes.

The .machines file I made is:
## begin .machines file ##
granularity:1
1:node001:1
1:node001:1
1:node002:1
1:node002:1
## end .machines file ##

I have 42 kpoints.  testpara_lapw tells me that it will split the list into 5 
smaller lists.  Four lists have 10 points, and one list has 2 points.  The 
output from testpara_lapw is:

### begin testpara output ###
Granularity set to 1
Extrafine unset

    klist:       42
    machines:    node001 node001 node002 node002
    procs:       4
    weigh(old):  1 1 1 1
    sumw:        4
    granularity: 1
    weigh(new):  10 10 10 10

Distribution of k-point (under ideal conditions) will be:

1 : node001(10) 10k
2 : node001(10) 10k
3 : node002(10) 10k
4 : node002(10) 10k
5 : node001(10) 2k
### end testpara output ###

Indeed when I run the calculation, it seems to send 10 kpoints to each cpu, 
and then 2 kpoints to node01.

Would it not make more sense to have the list split into 4 sublists, and
send 11 points to two cpus and 10 points?  That is, it seems like a 
distribution of:

1: node001(10) 11k
2: node001(10) 11k
3: node002(10) 10k
4: node002(10) 10k

would be more optimal.  No?

Thanks




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