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

Thank you all for your help. --bind-to-core increased the cluster performance by approximately 10%, so in addition to the improvements through the implementation of Open-MX, the performance now scales within expectations - not linear, but much better than with the original setup. On 30 January 20

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

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

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

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

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

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

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

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

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 benchmark that I am using. > > My primary question was about scaling between t

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

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. My primary question was about scaling between the nodes. I was not getting close to double the performanc

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

On 1/29/2014 8:02 AM, Reuti wrote: Quoting Victor : Thanks for the reply Reuti, There are two machines: Node1 with 12 physical cores (dual 6 core Xeon) and Do you have this CPU? http://ark.intel.com/de/products/37109/Intel-Xeon-Processor-X5560-8M-Cache-2_80-GHz-6_40-GTs-Intel-QPI -- R

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

Sorry typo. I have dual X5660 not X5560. http://ark.intel.com/products/47921/Intel-Xeon-Processor-X5660-12M-Cache-2_80-GHz-6_40-GTs-Intel-QPI?q=x5660 On 29 January 2014 21:02, Reuti wrote: > Quoting Victor : > > Thanks for the reply Reuti, >> >> There are two machines: Node1 with 12 physical c

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

Quoting Victor : Thanks for the reply Reuti, There are two machines: Node1 with 12 physical cores (dual 6 core Xeon) and Do you have this CPU? http://ark.intel.com/de/products/37109/Intel-Xeon-Processor-X5560-8M-Cache-2_80-GHz-6_40-GTs-Intel-QPI -- Reuti Node2 with 4 physical cores (i5-2

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

Thanks for the reply Reuti, There are two machines: Node1 with 12 physical cores (dual 6 core Xeon) and Node2 with 4 physical cores (i5-2400). Regarding scaling on the single 12 core node, not it is also not linear. In fact it is downright strange. I do not remember the numbers right now but 10 j

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

Am 29.01.2014 um 03:00 schrieb Victor: > I am running a CFD simulation benchmark cavity3d available within > http://www.palabos.org/images/palabos_releases/palabos-v1.4r1.tgz > > It is a parallel friendly Lattice Botlzmann solver library. > > Palabos provides benchmark results for the cavity3d

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

I am running a CFD simulation benchmark cavity3d available within http://www.palabos.org/images/palabos_releases/palabos-v1.4r1.tgz It is a parallel friendly Lattice Botlzmann solver library. Palabos provides benchmark results for the cavity3d on several different platforms and variables here: ht