Can GPUs run reliably in an orbital radiation environment at all? The combination of extreme transistor density and zero error checking seems like the opposite of what you'd want in a space processor.

This is just a vague intuition, but I feel like space hardening typically is done to insure very very high levels of reliability in all conditions. Im not sure how much easier the job might be if you could accept a sizable amount of transient failures. For many of these infernce systems, it feels like some "bad" processing might not really be a problem.

As others have said though, and as your "extreme transistor density" points to, high heat dissipation & energy usage are absolutely very real factors here. Still, Coral, back in 2017, was a half watt 2tflops inference engine, on a non-cutting-edge (at the time) process.

> not sure how much easier the job might be if you could accept a sizable amount of transient failures

Starlink pioneered this. Redundant COTS almost always beats rad hardening, particularly in LEO.

Why particularly in LEO? Benefits of some atmosphere still?

> Why particularly in LEO?

Faster degradation means quicker rejuvenation requirements. If you’re replacing your birds every five years in any case, the net benefit of rad hardening is diminished.

From a radiation standpoint I think the Earth's magnetic field helps more than the atmosphere at that altitude.