CSAR Bulletin issued in April 2005

Newton Stability

The stability of Newton has continued to be of concern despite recent patches to solve the issues. These issues and more have are addressed in the latest release of the SGI operating system (Propack 3.0). We intend to upgrade to this new version in a maintenance session on Tuesday 26th April. The new version of Propack will encompass the following features:

• Greater OS scalability.
• New version of glibc and math libraries (libm).
• Allows the addition of CXFS 3.2 which has important updates for the filesystems.
• Various bug fixes.
• All these are intended to lead to increased stability.

However in applying these important upgrades there are a few caveats:

• The upgrade may slightly affect numerical results, dependent on the use of libm functions.
• Codes may need recompilation under Propack 3.0, even if not necessary we do recommend codes are recompiled.

If any of these may be a problem for you then please contact the helpdesk as soon as possible.

A New Default Compiler for Newton

As part of the ongoing improvements to Newton we are going to change the default compiler from the Intel 7.1 series to the Intel 8.1 series. The version 8.1 compilers can give significant improvements to the performance of your code. After the maintenance session which is to be held on 26th April the new default compiler will be version 8.1 release 25. The existing default is version 7.1.044. This version is currently available on Newton via the module intel-compilers_8.1_new.

The most important issue is that code compiled with the 7.1 compiler is incompatible with that compiled with 8.1. Thus code compiled with the new default will not be able to be linked to libraries compiled with a 7.1 compiler, the libraries will need to be compiled too.

We recommend all users read this page before the changes.

A New Naming Convention for Compilers

As a response to user requests we are changing the way we name compilers on Newton. The new naming convention for compiler modules will make it easier to understand what compiler you are using and will enable changes to the default compiler to be managed more easily.

The names of the modules will now all carry the version number, intel-compilers_8.0.046 for example, and there is only one exception: intel-compilers. This is the new default compiler and is the module loaded by default, this has the same effect as loading intel-compiler_7.1.044.

SC2005: Advance Notice of Service Interruption

SC 2005, the 2005 conference in the Supercomputing series, takes place this November 12-18 in Seattle, Washington. In conjunction with this, CSAR, together with some of our users and our colleagues at HPCx and HPC services in the United States, are planning another trans-continental Grid computing demonstration, as a follow up to the TeraGyroid project in 2003.

Further details of this will be announced later. However, if this project goes ahead as planned, it will involve some interruption in the service over the period of SC 2005. We are in consultation with EPSRC about this, and we will keep users informed. We feel that exploring this exciting new technology, which has the possibility of providing enormous advantages to researchers in the future, justifies our doing this.