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Welcome to the QMUL HPC blog

When good compilers go bad

Many people rely on compilers, for languages such as C, C++ and Fortran, to create executable programs from source code. Just like our source code, compilers themselves may have bugs. In this post we look at common forms of compiler bug, with examples, and what we can do when our work is affected by such an issue.

Productivity tips for Apocrita cluster users

This article presents a selection of useful tips for running successful and well-performing jobs on the QMUL Apocrita cluster.

In the ITS Research team, we spend quite a bit of time monitoring the Apocrita cluster and checking jobs are running correctly, to ensure that this valuable resource is being used effectively. If we notice a problem with your job, and think we can help, we might send you an email with some recommendations on how your job can run more effectively. If you receive such an email, please don't be offended! We realise there are users with a range of experience, and the purpose of this post is to point out some ways to ensure you get your results as quickly and correctly as possible, and to ease the learning curve a little bit.

Simplification of parallel queues on Apocrita

We are simplifying the way that the multi-node parallel jobs are run on the cluster.

Currently, users wishing to run multi-node MPI jobs on the public queues must choose beforehand whether to run on the nxv parallel nodes or the sdv parallel nodes, and to configure the job accordingly for the number of cores on each type of node.

Cluster update summary

As part of our commitment to providing stable and manageable systems, here is a round-up of some recent updates we have been working on behind the scenes:

Getting REAL with Fortran

Fortran provides a variety of intrinsic representations of real numbers. In this post we look at what these representations are and how we choose a particular representation for our work.