A Fireside Alpha clip shows Elon Musk saying chips for space should run hot and that huge AI models can shrug off radiation bit flips
Elon Musk says a chip for space should run hot, since raising the temperature 20% in Kelvin cuts radiator mass in half, and that a multi-trillion parameter model does not care about a few bit flips “Well, I guess you want to design it to be more radiation tolerant and run at a higher temperature. So roughly, if you increase the operating temperature by 20% in degrees Kelvin, you can cut your radiator mass in half. So running at a higher temperature is helpful in space." "There’s various things you can do for shielding the memory, but neural nets are going to be very resilient to bit flips. So most of what happens for radiation is random bit flips." "But if you’ve got, like, you know, a multi-trillion parameter model and you get a few bit flips, it doesn’t matter. Heuristic programs are going to be much more sensitive to bit flips than some giant parameter file. So I just design it to run hot. And I think you pretty much do it the same way that you do things on Earth, apart from make it run hotter.”
Context
If AI chips can run hot and tolerate radiation errors, computing in orbit becomes simpler to build, which matters for SpaceX's space data center plans.
Fireside Alpha is an account that posts clips of business and tech leaders. The post does not say when or where the conversation was recorded, and it quotes the account's earlier clip of Jensen Huang on data centers in space, covered in the October 15 deck.
Deep dive
On the evening of October 19, Fireside Alpha posted a clip of Elon Musk explaining how he would design a chip for space.
In the quoted remarks, Musk says you want to design it to be more radiation tolerant and run at a higher temperature, because roughly, if you increase the operating temperature by 20% in degrees Kelvin, you can cut your radiator mass in half. In space, heat can only be shed by radiating it away, so smaller radiators mean lighter satellites.
He says there are various things you can do to shield memory, but that neural nets are going to be very resilient to bit flips, the random errors radiation causes. If you have a multi trillion parameter model and get a few bit flips, it doesn't matter, he says, adding that heuristic programs are much more sensitive than a giant parameter file. Otherwise, he says, you pretty much do it the same way as on Earth, apart from making it run hotter.
These are Musk's engineering views, not published test results. The radiator figure follows from the physics of thermal radiation, which rises steeply with temperature, but the post gives no data on how real AI chips fare in orbit.
The clip's date and setting are not given, so it may be older footage. SpaceX's plans for computing in orbit were covered in this deck on October 15.
What to expect next
Watch for SpaceX or its partners to publish test results on running AI chips in orbit, which would show whether higher temperatures and radiation errors are manageable in practice. Also watch for details on the Star Mind computer SpaceX is building with Nvidia, and for any confirmation of when and where this conversation was recorded. Clips like this one often resurface older interviews, so the original source would help date the remarks.