[OMPI users] Can't build openmpi-1.6.5 with latest FCA 2.5 release.

2014-01-30 Thread Brock Palen
I grabbed the latest FCA release from Mellnox's website. We have been building against FCA 2.5 for a while, but it never worked right. Today I tried to build against the latest (version number was still 2.5, but I think we have updated our OFED sense the last install). We are running MOFED 1.

Re: [OMPI users] Running on two nodes slower than running on one node

2014-01-30 Thread Tim Prince
On 1/29/2014 11:30 PM, Ralph Castain wrote: On Jan 29, 2014, at 7:56 PM, Victor > wrote: Thanks for the insights Tim. I was aware that the CPUs will choke beyond a certain point. From memory on my machine this happens with 5 concurrent MPI jobs with that bench

Re: [OMPI users] Running on two nodes slower than running on one node

2014-01-30 Thread Tim Prince
On 1/29/2014 10:56 PM, Victor wrote: Thanks for the insights Tim. I was aware that the CPUs will choke beyond a certain point. From memory on my machine this happens with 5 concurrent MPI jobs with that benchmark that I am using. Regarding your mention of setting affinities and MPI ranks do y

Re: [OMPI users] Running on two nodes slower than running on one node

2014-01-30 Thread Ralph Castain
On Jan 30, 2014, at 12:38 AM, Victor wrote: > I use htop and topand until now I did not make the connection that each > listed process is actually a thread... > > Thus the application that I am running is single threaded. How does that > affect the CPU affinity and rank settings? It aff

Re: [OMPI users] Running on two nodes slower than running on one node

2014-01-30 Thread Victor
I use htop and topand until now I did not make the connection that each listed process is actually a thread... Thus the application that I am running is single threaded. How does that affect the CPU affinity and rank settings? <-- as mentioned earlier I am a novice, and very easily confused :-

Re: [OMPI users] Running on two nodes slower than running on one node

2014-01-30 Thread John Hearns
Ps. 'htop' is a good tool for looking at where processes are running.

Re: [OMPI users] Running on two nodes slower than running on one node

2014-01-30 Thread Victor
Thank you for the very detailed reply Ralph. I will try what you say. I will need to ask the developers to let me know about threading of the main solver process. On 30 January 2014 12:30, Ralph Castain wrote: > > On Jan 29, 2014, at 7:56 PM, Victor wrote: > > Thanks for the insights Tim. I wa