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New and Updated Documentation for HLRE

SUPER-UX: MPI/SX User's Guide

A new guide from NEC with index in convenient PDF format. Login required

SUPER-UX: Shared Memory Parallelization Guide

A new guide from NEC with index and in convenient PDF format. Login required

32GB/s x 8?

The first result of many discussions after our presentation at this year's NUG meeting is: if you got problems scaling your code from one to eight CPUs you might want to run your program with F_PROGINF=DETAIL2. If the output then shows something like

  Memory Network (sec)  :         10.874843
while user time is

  User Time (sec)       :         15.487728
you got a big problem because you spend 70% of your time waiting for memory which kills scaling very efficiently. The difference to bank conflict time (which is low)
  Bank (sec)            :          0.004435
is that one task waits for banks currently used by other tasks. In the talk we tried to explain - among other things - under which circumstances memory congestion occurs and what can be done to avoid it.

Projektorientiertes Datenmanagement am DKRZ

Concept for a new project-orientated data management at DKRZ (as of January 2006)

FORTRAN90/SX Programmers Reference Guide

A new guide from NEC in convenient PDF format. Login required

NQS Job execution tracking

qflops now also shows efficiency information for multi-node jobs.

SX-6 Programming Quick Reference

All Fortran/C compiler switches and much more in one handy PDF. Download directly fom NEC.

NQS Job execution tracking

You know qstat, but there are more tools which help you keeping an eye on your jobs. Read more...

Programming the TX7

Our frontend server cross.dkrz.de can be used for more things than just cross compiling your models. There are some points to keep in mind, though. Read more ... (German)

Parallel programming with MPI

Tired of waiting for your job to finish in the SERI queue? Our new step by step guide to Parallelizing Sequential Code with MPI shows you how to use up to 128 CPUs of HLRE for your job and decrease turn around times dramatically. English version by Jana Meyer. Read more ...

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