An article in The Next Platform, One Small Step Toward Supercomputers in Space describes a small High Performance Computing system (HPC) built by Hewlett Packard Enterprise (HPE), to be brought to the ISS soon on CRS-12 for extensive testing in a space environment.
As HPE’s Mark Fernandez tells The Next Platform, the duo of HPE Apollo 50 machines is direct from the factory—in other words, no hardware hardening against radiation and magnetic disturbances has happened. Most of his team’ work has focused on the many tunable parameters for the CPU, memory, and solid state disk drives that are aboard ISS. What is different are the “lockers” that HPE built and tested for flight against the over 140 safety certifications required for on-board ISS gear.
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The system itself is running standard RHEL 6.8 across its benchmark suite and has features common to much larger supercomputers, including the Infiniband connections. “We went with the 56Gb/s optical interconnect because we imagined with copper, we would get more of a reaction from the radiation and magnetic fields. We also eliminated the spinning rust—there is no traditional hard disk because it would be affected by the same conditions. On each node there are eight solid state disks; four of those are small but fast, the others are large but slow so we can see what effects there might be on one versus the other,” Fernandez explains.
I'm wondering why a high speed copper interconnect between the (in this case two) nodes would be affected by radiation. There are many tradeoffs between copper and optical node-to-node connections (which I am assuming is what's being discussed here, rather than board-level or below) but I've never heard of radiation hardness being one of them.
Also, what would be the issue(s) related to magnetic fields? Are the fields any different in orbit than they are on Earth? Wouldn't any $\partial \mathbf{B} / \partial t$ effects be shielded by the computers housing? Or is that something not worth assuming?
