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Summary of Progress

All three phases of the project have been completed successfully, based on Castep 4.2 source code, though there remains some scope for optimisation and several possible extensions. Basic Castep calculations can be parallelised over bands in addition to the usual parallelisation schemes, and the large matrix diagonalisation and inversion operations have also been parallelised. Two band-independent optimisation schemes have been implemented and shown to work under certain conditions, but unfortunately neither is fast or robust enough to be useful to a general Castep user, and neither have been parallelised fully.

Despite the lack of an effective band-independent optimiser, the performance of Castep on HECToR has been improved dramatically by this dCSE project. One example is the standard benchmark al3x3, which now scales effectively to almost four times the number of cores compared to the ordinary Castep 4.2 (see figure 1.1).

Figure 1.1: Graph showing the performance and scaling improvement achieved by this dCSE project (using 8-way band-parallelism) compared to the ordinary Castep 4.2 code for the standard al3x3 benchmark.
\includegraphics[width=0.9\textwidth]{headline.eps}

The changes made in this dCSE project are expected to be merged into the main Castep source code for version 4.4, due for release in the latter quarter of 2008. It is hoped that many of the restrictions of the new scheme will be lifted in time for Castep 4.5.


next up previous contents
Next: Castep Up: Introduction Previous: The dCSE Project   Contents
Sarfraz A Nadeem 2008-09-01