MPI on NT- Further Investigations

1. MPI on NT- Further Investigations Mark Baker School of Computer Science University of Portsmouth Milton Campus Southsea, PO4 8JF Tel: +44 (1703) 844285 Fax: +44 (1703) 844006 Email: mab@sis.port.ac.uk URL: http://www.dcs.port.ac.uk/~mab/

2. Talk Overview • NT MPI Environments • WinMPICH (PD) • MPI/PRO (COM) • WMPI (PD) • PaTENT (COM) • HPVM (PD) • Performance tests and results. • Conclusions.

3. Aim of Project • Evaluate the functionality and performance of the various MPI environments on NT • Interested in using PC’s for development of parallel tools and applications.

4. Why Run Applications on NT Platforms ? • Traditionally • Science and industry used UNIX workstation. • PC-based machines were for administrative work and word processing. • Rapid convergence in performance and kernel-level functionality of UNIX and PCs in the last 3 years • Introduction of high-performance Pentium-based machines. • Window NT operating system.

5. Why Run Applications on NT Platforms ? • Increased level of interest in utilising PC-based systems as some form of resource for parallel computing. • Coupled with the comparatively low cost of PCs and their widespread availability in both academia and industry has helped initiate a number of software projects whose primary aim is to harness these resources in some collaborative way.

6. WinMPIch • WinMPIch from the Engineering Research Center at Mississippi State University is a port of MPICH for Windows NT platforms. • MPI processes communicate with each other via shared memory or over a network. • Release consists of source and binaries for a set of libraries and servers configured to be compiled and linked using MS Visual C++. • Frozen development, but still available - www.erc.msstate.edu/mpi/mpiNT.html

7. MPI/PRO • Commercial software from MPI Software Technology, Inc. • The company is a spin-off from Mississippi State University and led by Tony Skjellum. • MPI/PRO is a new product announced in April 1998. • MPI for NT on Intel and Alpha platforms using MS Visual C++ and Digital Fortran. • Available from... www.mpi-softtech.com/products

8. WMPI • WMPI from the Instituto Supererior de Engenharia de Coimbra, Portugal is a full implementation of MPI for Microsoft Win32 platforms. • WMPI is based on MPICH and includes a P4 device standard. • The WMPI package is a set of libraries (for Borland C++, MS Visual C++ and Digital Fortran).

9. WMPI • WMPI release provides libraries, header files, examples and daemons for remote starting. • WMPI can co-exist and interact with MPICH/ch_p4 - Win32 and UNIX workstations can interact. • Under development and is freely available -http://dsg.dei.uc.pt/w32mpi/

10. PaTENT • Commercial release of WMPI: • Documentation included. • License Management. • More frequently and earlier updated libs. • Support and assistance included. • Product shipment and packaging. • NT Service routine, admin tools and. installation routines are different (click-wrap). • http://www.genias.de/products/patent/

11. Illinois Fast Messages (FM) • FM-MPI is from the Dept. of Computer Science at the University of Illinois at Urbana-Champaign. • FM-MPI is a version of MPICH built on top of Fast Messages. • The FM interface based on Berkeley Active Messages. • Freely available - www-csag.cs.uiuc.edu /projects/comm/mpi-fm.html

12. Illinois Fast Messages (FM) • FM was originally developed on a Cray T3D and SPARCstations connected by Myrinet. • FM has a low-level software interface - a number of high-level APIs have been developed on top of FM; these include MPI, SHMEM and Global Arrays.

13. C Test Suite • The C test suite used was that developed by IBM and had been modified by ANL to comply fully to the MPI standard and be compatible with the MPICH. • The suite consists of 57 codes that tested the following MPI calls and data types: • Collective operations, Communicators, • Data types, Environmental inquiries, • Groups, Point to point, Virtual topologies

14. Functionality Results • WinMPICH • All C codes compiled OK. • SM - all C codes ran OK. • DM - couple of problems with C codes… • No Fortran wrapper.

15. Functionality Results • MPI/PRO • Not fully tested, but tests so far seem fine. • SM - not tested yet. • DM - not tested yet. • Fortran - limited testing seems OK...

16. Functionality Results • WMPI • All C codes compiled OK. • SM - all C codes ran OK. • DM - all C codes ran OK. • Fortran wrappers seem OK on codes compiled and run so far. • ORNL reported missing Fortran functions MPI_PAUSE() !? and MPI_WAIT().

17. Functionality Results • PaTENT • Currently functionally the same as WMPI... • All C codes compiled OK. • SM - all C codes ran OK. • DM - all C codes ran OK. • Fortran wrappers seem OK on codes compiled and run so far - see comments on missing functions in WMPI.

18. Functionality Results • HPVM • C codes compiled - many errors. • SM - compiled codes ran OK. • DM - compiled codes ran OK. • Fortran wrapper written in Visual Fortran, so problems encountered - can be “hacked” to work.

19. Performance Tests • The aim of the performance tests undertaken were restricted to getting an indication of the low-level performance of MPI on NT. • Investigating the performance of “real” applications running using MPI on NT left to a later time...

20. Multi-processor Benchmark - PingPong • PingPong - increasing sized messages are sent back and forth between processes. • This benchmark is based on standard blocking MPI_Send/MPI_Recv. • Provides information about latency and uni-directional bandwidth.

21. Machines Used • NT Workstations (SP3) - dual processor (200 MHz Pentium Pro, 512K on-chip cache), with 128 MB. • Solaris 2.6 - dual processor (200 MHz UltraSparc), with 256 MB.

22. PingPong - Shared Memory

23. PingPong - Distributed Memory

26. PingPong Results Summary

27. Overall Conclusions • WMPI/PaTENT • In terms of functionality and performance, clearly best environments of those investigated at the moment. • WinMPIch • Functionality is good and performance almost matches that of WMPI in SM. • In DM has problems with reliability, functionality and performance.

28. Overall Conclusions • MPI/PRO • Not enough time to do exhaustive tests. • Functionality seems OK. • Perfromance is much better the WinMPIch but still not as good as WMPI/PaTENT - new version ... • HPVM • Designed for Myrinet networks and FM protocols. • MPI, SHMEM and Global-Arrays interfaces make it potentially very desirable environment. • MPI via WinSock not target and not opimised. • Performance is poor under WinSock.

29. Conclusions: Problems • NT • Remote administration - vnc from Olivetti • DOS Consoles... • Binary placement. • Memory usage, seems excessive... • MPI Environments • IO needs to be dealt with. • User manuals. • Sources and makefiles (project files) needed. • User support…. commercialisation...

30. Ideal Environment • Intelligent Configuration • Recursion. • stdio and Disk IO placement. • Supporting Tools • Set up of binaries on remote machines. • Debugging and profiling support. • Analysis and monitoring tools. • Source code would be helpful or prompt response to bug reports.

31. Where to find... • MPI on NT paper www.dcs.port.ac.uk/~mab/Papers/PC-NOW/ • mpiJava Paper www.dcs.port.ac.uk/~mab/Papers/EuroPar98/ • This talk www.dcs.port.ac.uk/~mab/Talks/EuroPVM-MPI98 • mpiJava Web site and download. www.npac.syr.edu/projects/pcrc/mpiJava/

32. Acknowledgements • NPAC, http://www.npac.syr.edu • TOPIC - http://www.topic.jtap.ac.uk/ • Full version of paper and further information can be found at: • http://www.dcs.port.ac.uk/~mab/TOPIC/