[rented_mule]

> What's the difficulty of a 1GW datacenter in space?

Simple back of the envelope calculations?

Let's assume your numbers are correct and that panels in space can generate 10x the power per square meter per 24 hour period (due to efficiency, lack of night, and lack of atmosphere/weather). That means 10 KM^2 are needed for one such data center. The largest we've built in space is ~3,000 M^2 on the ISS. So one of these DCs in space will require an array ~3,000 times the size of the largest we've built before. Or, it's going to require ~3,000 satellites, each with an array the size of the largest we've ever deployed.

The largest Starlink satellites currently deployed generate less than 30 KW each. We'd need more than 30,000 of those to generate this much power. Starlink has launched ~12,500 to date, with ~10,000 still functioning. So 3x the size of the functioning fleet that's taken 8+ years to deploy. Currently, we are deploying well under 5,000 per year. Let's assume we can come up with enough spare capacity to launch 5,000 per year. That's 6 years to deploy the first 1GW DC. By the time we get to 1GW, the average GPU is 3 years old. So we need to continue to deploy 5,000 satellites per year to maintain 1GW of GPUs that are, on average, 3 years behind current generation GPU designs.

This is all before we get to the economics of launching, the cost of the satellites themselves, heat dissipation, radiation hardening, hardware failure rates (~20% of deployed Starlink satellites are no longer functioning), etc.

[mike_hearn]

The whole thing does assume Starship works, so at that point satellites could be launched much faster.

I assume Starmind would use Tesla designed chips, which removes Nvidia's margin and so the cost of the chips is not necessarily so high.

Rad hardening isn't important at low altitudes, and inferencing can smoothly recover from glitched calculations/lockups.

I don't know if it makes economic sense or ever will, but technologically it does seem possible. And if you can't build on Earth for political reasons, then space can win by default.

[rented_mule]

In terms of what we decide to build, impossible vs. impractical is not a particularly interesting distinction (that distinction can give rise to fun science fiction). Practicality is at the core of good engineering, and possibility is just the first of many steps in evaluating practicality.

If we're going with a distributed approach, there are other ideas that are more practical. For example, send 1 KW boxes to a million people (< 1% of American homes, but there's no reason to limit this to the US). Very roughly, these are beefed-up gaming consoles - you could even start with existing gaming consoles. That box plugs into electricity and ethernet. Pay each of those people $1,000 a month to leave their box running 24/7. For people with a lot of solar at home, it could be a nice income stream. At $1B per year for payouts, it's far cheaper than doing it in orbit. And it doesn't rely on promised but as-yet undelivered technologies. But data centers are probably more practical.

[mike_hearn]

I've thought of that but it wouldn't be easier.

1. Running modern models requires a whole rack of extremely loud equipment that can easily consume 130kw. That's not a load you can or should run at home.

2. It would require a very strong end-to-end implementation of confidential computing to keep the prompts encrypted. If there is any flaw in that infrastructure at all, like someone discovers a way to physically tamper with the hardware to read the GPU memory, then the entire network is a writeoff and would have to be replaced. That's a massive risk. Confidential computing can work in cases where hardware replacements aren't an issue or where the vendor has a long history of successfully defending the platform. But Nvidia is the only GPU vendor with these capabilities and their CC is untrusted.

Putting the workloads in space means noise and data privacy aren't an issue, assuming you trust SpaceX to not peek at your prompts on their way to the cluster.

[mike_hearn]

Sorry, by "their CC is untrusted" I meant it's not clear how much it's been attacked in the wild, not that there's consensus it's bad or anything.