A neuromorphic computer hosted at the UK's University of Manchester suffered an outage last month.
As first reported by The Register, the university's SpiNNaker machine was brought down after its cooling system failed on April 20.
SpiNNaker - AKA Spiking Neural Network Architecture - is a project that aims to simulate parts of the human brain by connecting hundreds or thousands of Arm cores.
Now retired Professor Steve Furber - the creator of the original Arm architecture - told The Register: "SpiNNaker is hosted in the Kilburn Building, which was completed in 1972 as a purpose-built computer building and, as such, has a plant room that supplies chilled water as a utility to all the central machine rooms.
"The SpiNNaker room was built to house the machine in 2016 in what used to be the mechanical workshop, and is cooled by circulating hot air from the back of the cabinets through a plenum chamber into chillers at either end that blow the air through a cooling system using the building's chilled water."
The issue experienced in April was related to the chilled - or not - water. With the water not chilled, temperatures began to rise, and the servers failed to automatically shut down.
Furber thought that individual SpiNNaker boards may have had an automatic over-temperature shutdown which "may have protected the SpiNNaker hardware from damage," but network switches and power supplies remained turned on, both of which have been harmed by the overheating incident leaving SpiNNaker unable to be tested.
Furber further told The Register: "We have had a few issues with the cooling system in the nine years that the machine has been operational, but these have not previously led to any damage," adding that he thinks the Easter holiday, meaning that staff were not on site, might have added to the problem.
SpiNNaker is now back up for internal users at around 80 percent of capacity and undergoing tests.
SpiNNaker was built by the Advanced Processor Technologies Research Group (APT) at the School of Computer Science, University of Manchester, and is part of the European Union's Human Brain Project.
The system uses custom chips created by the team behind the project, which feature 18 ARM968 processor nodes. The project was later set to launch the SpiNNaker 2 chip in 2023, which would have 160 Arm Cortex-M4F nodes per package.
In October 2018, SpiNNaker reached one million cores in a single machine.
