Data Processing Using GPUs for The MWA

Wayth R, Dale K, Greenhill L, Mitchell D, Ord S, and Pfister H.

(Bulletin of the American Astronomical Society, 2007.)

The Murchison Widefield Array (MWA) is a new 80-300 MHz synthesis radio telescope under construction in Western Australia. The science objectives of the MWA include the epoch of reionization, the heliosphere, the ionosphere, transients and a Southern sky survey. The 500 antennas of the telescope will generate 16GB/s of raw visibilities, which must be processed in real-time including calibration of the instrument and ionosphere. A dedicated supercomputer is required for this task. Modern, PC-based Graphics Processing Units (GPUs), originally developed for computer games, offer close to Tflop/s performance as a cheap, off-the-shelf component. With the development of easy to use programming tools, GPUs can be used by the scientific community for compute-intensive tasks. Much of the processing for the MWA real-time system is particularly well suited to GPUs. We describe the types of algorithms used in the real-time system and the improvement in runtime that has been achieved using an nVidia G80-based GPU compared to a regular CPU. We estimate that a GPU-based real-time supercomputer for the MWA would be able to process the data with an order of magnitude fewer nodes than a traditional cluster.