Non-deterministic event brokered computing

This paper reviews the massively micro-parallel compute system POETS (Partially Ordered Event Triggered System) and illustrates its potential for speeding up demanding applications. Application domains that benefit from POETS include simulations of physical systems that can be discretised as a mesh. The problem graph is distributed over a large compute mesh; each mesh vertex contains a processor – an FPGA-based RISC-V thread supporting custom instructions in our prototype – and a small amount of local problem state data. There is no central overseer of any sort and processors cannot see memory besides their own. A problem graph vertex interacts with a neighbour to send a state change by sending an asynchronous packet. The packets are fixed size and small – currently 64 bytes – and the hardware communications infrastructure is very fast. Applications can use an asynchronous ‘packet storm’ approach; run synchronously using a hardware idle barrier or run in a globally asynchronous, locally synchronous manner. Results show significant wallclock speedup and power consumption improvement over conventional systems: for one application we show a 40-fold speedup over a conventional CPU-based system; versus a multi-GPU system, the POETS cluster is 26% faster, 60% more power efficient, and 34% more energy efficient.