[mvapich-discuss] Number of IB QP's

[Lars Paul Huse]

Hi all,

As my source of difficult MPI questions:

How many QP's will be used for a large application run with MVAPICH / 
MVAPICH2 1.x ? aka' given an application running all-to-all traffic of 
random size on <P> MPI processes  (= #cores) behind each HCA on <N> 
nodes/HCA's (i.e. a total of N*P application processes) will use <Q1> 
QP's on rank 0 and <Q2> QP's on the rest...

Will Automatic path migration affect the number of QP's used ?
Will using the MVAPICH2 multi-rail feature affect number of QP's used ?
Other factors / features that will affect the number of QP's ?

/lars paul