An Efficient Real-time Data Pipeline for the CHIME Pathfinder Radio Telescope X-Engine
Abstract
The CHIME Pathfinder is a new interferometric radio telescope that uses a hybrid FPGA/GPU FX correlator. The GPU-based X-engine of this correlator processes over 819 Gb/s of 4+4-bit complex astronomical data from N=256 inputs across a 400 MHz radio band. A software framework is presented to manage this real-time data flow, which allows each of 16 processing servers to handle 51.2 Gb/s of astronomical data, plus 8 Gb/s of ancillary data. Each server receives data in the form of UDP packets from an FPGA F-engine over the eight 10 GbE links, combines data from these packets into large (32MB-256MB) buffered frames, and transfers them to multiple GPU co-processors for correlation. The results from the GPUs are combined and normalized, then transmitted to a collection server, where they are merged into a single file. Aggressive optimizations enable each server to handle this high rate of data; allowing the efficient correlation of 25 MHz of radio bandwidth per server. The solution scales well to larger values of N by adding additional servers.
- Publication:
-
arXiv e-prints
- Pub Date:
- March 2015
- DOI:
- 10.48550/arXiv.1503.06189
- arXiv:
- arXiv:1503.06189
- Bibcode:
- 2015arXiv150306189R
- Keywords:
-
- Astrophysics - Instrumentation and Methods for Astrophysics
- E-Print:
- 5 pages, 4 figures, In Press, IEEE ASAP 2015