ESRF, Grenoble, France
The ESRF initiated few years ago the development of a novel platform for optimised transfer of 2D detector data based on zero-copy Remote Direct Memory Access techniques. The purpose of this new scheme, under the name of RASHPA, is to efficiently dispatch with no CPU intervention multiple parallel multi-GByte/s data streams produced by modular detectors directly from the detector head to computer clusters for data storage, visualisation and distributed data treatment. The RASHPA platform is designed to be implementable using any data link and transfer protocol that supports RDMA write operations and that can trigger asynchronous events. This paper presents the ongoing work for the first implementation of RASHPA in a real system using the hardware platform of the Medipix3 based SMARTPIX hybrid pixel detector developed at ESRF and relying on switched PCIe over cable network for data transfer. It details the implementation of the RASPHA controller at the detector side and provides input on the software for the management of the overall data acquisition system at the receiver side. The implementation and use of a PCIe switch built with components off-the-shelf is also discussed.
