Dear All, I 'm trying to understand the meaning of TileSize and ProcessCount elements to describe a MPI + OpenMPI job. For example, in a job submission request for a batch scheduler (LoadLeveler, PBS and so on) I can specify : tasks per job=3 threads per task=4 processors per task=4 in order to get 1 thread per processor ( processors per task = threads per task ). I can set "nodes per job"=2 (with a a configuration of 8 cpus per node) or leave the scheduler sets this value. For what I understand in JSDL there are : [tileSize] tasks (processes) per group [ProcessCount] tasks (processes) per job [CPUCount] processors per job (with ResourceCount=1) [CPUCount + ResourceCount] processors per node + nodes per job from which I can get : tasks per job = [ProcessCount] = 3 threads per task = [ ? ] = 4 processors per task = [ CPUCount * ResourceCount / ProcessCount ] = 4 nodes per job = [ ResourceCount ] = 2 And so what is a "group of processes (tasks)" ? Is there a way to specify "threads per task (process)" ? Best Regards, Claudio Cacciari ========================================================= Claudio Cacciari CINECA - Via Magnanelli 6/3 40033 High Performance System Group Casalecchio di Reno - Bologna - ITALY e-mail: c.cacciari@cineca.it http://www.cineca.it Tel: 051/6171411 - Fax: 051/6132198 =========================================================