Jülich goes Vector Computing on Cray SV1exJülich 25 July 2001 ZAM (Central Institute of Mathematics) at Research Centre Jülich stops the operation on the Cray T90 and moves to a Cray SV1ex with 16 processors and 32 GByte memory.
The good old Cray T90 with 10 processors and 8 GByte memory
showed hardware instabilities during the last time. As there are
no new, spare parts available, ZAM could expect a total crash
with longer breakdowns. Thus the centre decided to switch off
the machine on 31. October 2001. Its functionality will be
continued by an upgrade of the installed Cray T90 to the model
Cray SV1ex by 1. October 2001. This machine is binary compatible
to the J90.
The computer has 16 processors with a total of 32 GByte main
memory. This machine supports applications that need vector
processing or software that is only available on vector
machines. ZAM says that it supports this type of processing for
the next years. Although the peak performance of the SV1ex
processor is a bit higher as that of the T90 (2 GFlop/s compared
to 1.8 GFlop/s on the T90), the application performance will be
lower, because of the much lesser bandwidth between memory and
processors.
As the upgraded machine uses the same instruction set as the
J90, programs have to be recompiles, which are migrated from the
T90 to the SV1ex. This machine uses the Cray proprietary
floating point format compared to the IEEE format which is used
on the T90 and Cray T3e. Thus there could be numerical
differences in the results. The same is true for binary data
files, which have to be converted.
Uwe Harms |
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