Solved: Nwchem 6.3 running 2-5 times slower than 6.1.1


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Gets Around
I've patched and tested it, and discovered that I made a typo above in the list over the number of SCF iterations -- 6.3 does one more cycle than 6.1.1 it seems (still same number of DFT optimisation steps, 4, though)

I think it worked: I get 10, 6, 6, 2 and 3 SCF iterations
c.f.
Quote:

6.1.1 does 9, 7, 6, 4, 5 and 2 SCF iterations.
6.3 does 10, 8, 7, 7, 7, 7 and 7 SCF iterations.


I've got too many versions and too much data floating around, so I'll start with freshly extracted sources and redo the tests.

From what I can see the execution times are now down to about the same as 6.1.1 when you patch 6.3 with Iswtch,path and set ARMCI_NETWORK=SOCKETS:
 Total times  cpu:       39.1s     wall:       40.9s
 Total times  cpu:       45.3s     wall:       47.1s
 Total times  cpu:       46.1s     wall:       48.1s
 Total times  cpu:       41.9s     wall:       43.7s
 Total times  cpu:       47.2s     wall:       51.2s
 Total times  cpu:       44.6s     wall:       47.2s
 Total times  cpu:       38.9s     wall:       40.8s
 Total times  cpu:       44.9s     wall:       47.1s
 Total times  cpu:       44.7s     wall:       46.9s
 Total times  cpu:       45.9s     wall:       47.9s



Thank you Edo!

I'll do some more tests and report back if it looks different.