QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: bjnagare on December 15, 2009, 20:24

Title: ATK in parallel
Post by: bjnagare on December 15, 2009, 20:24

Hello ATK users,

I am using atk in parallel mode with 4 core (1 CPU) for SCF calculation. why all four core are not using same time. For clearity, output of processes is shown below;

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND           
15476 bjnagare  25   0  279m 258m   9m R  101  1.7 367:22.01 atk_exec           
15473 bjnagare  25   0  267m 246m 9804 R  100  1.6 278:27.85 atk_exec           
15474 bjnagare  25   0  293m 271m 9800 R  100  1.8 278:17.54 atk_exec           
15472 bjnagare  25   0  299m 277m 9808 R  100  1.8 278:48.79 atk_exec 

What is reason behind it?

Regards,
Nagare   

Title: Re: ATK in parallel
Post by: Nordland on December 15, 2009, 22:15

Not all algorithms in ATK is not possible to perform in parallel, and these parts are only done on the master process, hence it will appear as taking more time,
than the others as they from time to time have to wait a short while for the master process to complete a task.