Comment by urams
16 hours ago
Very possible Elon is doing this to make give Anthropic better chances against OAI while he attempts to reshape xAI.
Also possible he sees infra as the future of xAI if he really believes in the value of space compute.
Hard to see this any of this as anything other than a bearish sign for Grok though.
That's very doubtful given recent news that Colossus is running at 11% capacity and has hundreds of thousands of idle GPUs. xAI acquired too many GPUs and currently doesn't have enough customers to use them. That's why they are making compute deals with Anthropic and Cursor.
xAI is bleeding money and this compute deal with Anthropic will pay for all of xAI's capex ($25 billion) in 2 years.
11% MFU does not mean 89% of GPUs are idle, it means that they're using the GPUs ineffectively.
11% capacity is not 11% MFU. The first is about actually using the hardware for something in the first place, the latter is about how efficiently you compute. Different things.
The post you’re referring to doesn’t even include “89%” or “idle”. I’m not sure I understand the point you’re making then rebutting.
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This might actually be worse from a power costs standpoint.
> will pay for all of xAI's capex ($25 billion) in 2 years
This is a confusing framing; you pay down capex with profit not revenue, and there is presumably a high opex cost.
Nevertheless, you are still talking about 15B / year - when the initial investment was < 30B. That investment also probably covers things like power, salaries, etc.
So you are still covering all of that.
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free cash flow pays down capex
> space compute
Heard anybody remotely competent about space talk the topic? It's pretty much a literal laugh every time.
Some of the proposals are laughable, some of the example calculations are. The idea of running AI training sounds extremely challenging. But the idea of inference in space doesn't seem absurd
The power budget of a starlink v2 mini satellite is estimated at around 20kW based on the known solar panel size. That also matches what a satellite of that size would roughly dissipate without dedicated radiators, using just some heat pipes to spread the heat evenly over the satellite's surface. There is nothing fundamentally preventing you from taking the same satellite design, remove most of the comms payload and instead put 15kW of GPUs there. Or about 10 GB200 including the CPUs, networking, etc that you need along with the GPUs
Now, do the economics work out for $300k worth of compute for each satellite, in an environment where maintenance is impossible and degradation will be higher than on the ground? Probably not right now, but in a couple years they might
The starlink satellites have hall effect thrusters, and presumably beefy laser and radio comms systems that will account for a lot of the energy budget. Also, they are sometimes in the earth's shadow, a naive calculation says they have 2x the solar budget they need, in order to charge up batteries for shade-time operations. There is no where near 20kw of compute in a single satellite, and thus no where near 20kw of heat to get rid of.
Furthermore, xAI's colossus supercomputer is specced at 250MW. And this seems to be a number that'll just increase over the coming years with new bigger DCs.
To match this level of performance they will have to launch what, ~15k satellites _per_ equivalent datacentre?
Regarding cooling: you can't just cover the outer surface with pipes. You cant't dissipate the heat, you need to _radiate_ it away. You need to point that surface to the deep dark cold of space. If you point it to the sun, you will heat your satellite. Think a massive "reverse solar panel" that works with infrared. You need surface area, and loads of it.
I'm not saying this is impossible. Obviously elon will prove us all wrong because he's stubborn like that. But there is no way this will ever be economically viable when competing with terrestrial based systems.
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How is this not absurd? What is the benefit? Space is a harsh environment, with issues due to solar radiation etc, etc. And it's permanently 100ms away from any user.
Tl;dr — but it’s too heavy
You’re making some decent points here, but you’re either forgetting or ignoring the major thing that people usually neglect to mention when they want to make a case for this (crazy) idea — weight. Unless SpaceX is going to completely redesign hardware such that it is optimized entirely for its mass, it requires many (many) launches to even get a small set of racks into space. I don’t normally get up in arms about the CO2 emissions of data centers, I think there is offsetting value created by their use, but I would absolutely protest trying to put data centers in space and do my best to shut down the hundreds, if not thousands of launches it would take to achieve even a tiny fraction of an AI data center.
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While I agree with you on the merit of the idea, rockets that can take off and then land vertically without damage were also laughable pre-SpaceX.
NASA had literally done it. It was never laughable, just thought to be an incredibly difficult engineering challenge.
I think compute in space suffers less from being "impossible" and more from being "impractical". It is plenty easy to put compute in space. It is just still silly expensive and by the time your equipment makes up the cost of putting it in space, it will be well out of date.
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It is absolutely baffling to me how frequently I hear people talk about this around me. There is no way this is happening anytime in the near future.
But if the US isn’t the first to put an AI on the moon, we’ll lose the AI space race!
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You don't have to actually have an orbiting datacenter for the idea to work. You just have to convince enough people. Once you've done that, you can claim that regional regulations don't apply to your data because the data is in orbit. Its not like somebody is gonna go up there and catch you in the lie.
Out-of-regulatory-reach is what they'll actually be selling. It can be on earth, it just has to be sufficiently hidden such that you can claim that it's in space.
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Space compute isn't real though, it's just a scheme to pump the value of SpaceX before IPO by associating it with AI. It's really hard to cool things in space, because there's no matter to transfer the heat away. All you've got is radiative cooling, and that's really really slow.
Right, also Anthropic has been having difficult time getting more GPUs
xAI is a dead company; you don't sell compute if you're growing.
More promising is that cursor is training a model using it.
That would be absolutly ludicris.
His own product is competing against anthropic.
It's a money maker. Maybe not a number one spot, but they don't have to stand up any more datacenters.
His product should be the money maker.
He believes in the value of the idea of “space compute” for attracting investors to SpaceX. But the existence of the idea of “space compute” as a better way to deploy datacenters (along with everything else Musk has claimed in the past decade) should give everyone pause as to the plausibility of literally everything else he says.
> along with everything else Musk has claimed in the past decade
* mass produced EVs * Neural links to brain * reusable rockets * more efficient tunnel digging
Dude has a pretty good record of taking stuff in R&D and making pretty real products and/or companies. Can you name someone better?
> He believes in [...]
...the value of having others buy the idea of space computing. I don't think he himself believes in what he says.
> should give everyone pause as to the plausibility of literally everything else he says.
That ship has sailed, we're in the Age of Cults. If you're a believer you're probably also invested in his companies, so your mind is doubly-clouded.
> so your mind is doubly-clouded
Further I think external agents are controlling their mind.
We could see the first company vertically integrated from etching to chip to data center
That's Intel. Probably IBM too, though they've been doing mass manufacturing with TSMC (and GloFo before) for years instead of their fabs. I wouldn't be surprised if HP did similar things back in the 80s.
We wont for anytime soon.
Intel and TSMC are not what they are today just because they buy a very expensive EUV Machine from ASML but because they have the knowledge and infrastructure to even use these machines.
What do you mean by etching? Google does also it's own chip design with TPUs, data centers, and models but afaik only TSMC Intel and Samsung do the actual semiconductor fabrication
Assume he's referring to SpaceX's https://en.wikipedia.org/wiki/Terafab
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IBM was doing this since the 50s.