[Pw_forum] time for calculation of el-ph interactions of graphene supercell

[L.F.Huang]

Dear prof. Kohlmeyer:
  Thank you for your kind help!
  I have read your previous demonstration to vega. I am also doing
some tests now. I am sorry for my limitation in computer knowledge!
And the computer I am using is thousands miles away from me,so I
just find information from its webpage, which I list below and try
to make it as complete as possible:
  Peak Performance:  	  10.2Tflops
  Computing Nodes: 	  512 4-way nodes,each composed of 4 CPUs
  Storage Nodes: 	  16 4-way nodes,each composed of 4 CPUs
  Accessing Nodes: 	  4 4-way nodes,each composed of 4 CPUs
  CPU:           	  AMD OPTERON 850, 2.4GHz，2128 CPU tatally
  System Memory: 	  4256GB
  System Storage: 	  20TB
  Architecture:           Cluster、Myrinet 2000
  Operating System: 	  Turbo Linux 8.0
  Language:               C, C++, Fortran77/90/95, Java
  Compliers:              gcc3.2.2-4,  Java1.2 ,  tcl/tk 8.0, Perl 5.0
  Mathematic Libraries:   NAG ACML 1.5, ATLAS 3.6
  Parallel Environment:   BCL4、Myricom GM, MPI 1.2, PVM 3.3.6, JobManager
  Tools:                  gdb5.3, OpenLDAP2.2, Python2.3, X-window
  Sysytem Administration: LSF, Dawning Cluster Operating System, DCOS,
                          including DCMS(Dawning Cluster Management System
                          ), DCIS(Dawning Cluster Installation System),
                          DCMM(Dawning Cluster Monitor and Management
                          System), Mterm(Multi-terminal software), Dawing
                          Large-Scale KVM System(SKVM)

Another question is:
   Prof. Kohlmeyer, you have mentioned that not all components in
Q-E support k-points parallelization fully. I wonder are there
still any other components like that besides postprocessing components?
Are elphon.f90 and elph.f90?
Thanks!

                                            Yours Sincerely
                                               L.F.Huang






> On Sat, 6 Sep 2008, L.F.Huang wrote:
>
> LFH> PostScript:
> LFH>   Amount of memory: 2GB per node
> LFH>   kind of interconnect: myrinet 2000
> LFH>   No. of reduced k points: 52
> LFH>   No. of nodes: 13 (with npool by default 1)
>
> parallelization over k-points is always the
> first item to try. not all components in Q-E
> support it fully, but when it is supported,
> it is superior over the g-space parallelization,
> which in itself has scaling limitationss. please
> see how in my previous demonstration to vega,
> the execution time goes up significantly, when
> using too many nodes and the wrong parallelization
> scheme. i would also check, whether your machine
> is communicating correctly. i've seen myrinet machines
> just stall occasionally, due to firmware crashes.
>
> LFH>   Parallel environment: MPI 1.2
>
> i assume it is MPICH-GM. mpi 1.2 does not make that
> much sense (there is an MPI 1.2 standard but that
> numbering is usually independent of the MPI standard
> version. e.g., i'm using OpenMPI 1.2.7 and it implements
> all of MPI 2.0 ... ).
>
> LFH>   Math library: NAG ACML 1.5、ATLAS 3.6
>
> ACML is from AMD not NAG, and that would conflict
> with ATLAS as both implement BLAS/LAPACK.
>
> LFH>   No. of cpus per node: 4
>
> which type? looks like opteron dual-core?
>
> cheers,
>    axel.
>
> --
> =======================================================================
> Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
>    Center for Molecular Modeling   --   University of Pennsylvania
> Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
> tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
> =======================================================================
> If you make something idiot-proof, the universe creates a better idiot.