Hello,

I performed some test run to see how many processor should I use for my problem. Following is what I observed:

number number processor

of of grid

processors dynamic

steps in

an hour

4 18800 1x2x2

8 27750 2x2x2

12 34250 2x2x3

16 39200 2x2x4

#20 30500 2x2x5

24 43350 2x3x4

#28 42050 2x2x7

32 47200 2x4x4

#36 43450 2x3x4

40 50600 2x4x5

#44 45950 2x2x11

#48

#52 39350 2x2x13

#56 40700 2x4x7

60 48500 3x4x5

64 50450 4x4x4

a simple fit reveals: time/step ~ 1/(sqrt(# of processors))

However, not all choices of number of processors is a good choice, e.g. using 20 processors takes longer than 16 processors.

Wondering if there is way I can choose processor grid and if this is related to time/step ? Is there also some relationship between total

number of atoms and max number of processor that could be used ? The above calculations were performed on 464 atoms.

I have also attached time/step (in hours) vs number of processors plot with this email.

Please let me know.

Thank you,

Vivek