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kolbe commented on Starcloud can’t put a data centre in space at $8.2M in one Starship   angadh.com/space-data-cen... · Posted by u/angadh
energywut · 2 months ago
Putting a datacenter in space is one of the worst ideas I've heard in a while.

Reliable energy? Possible, but difficult -- need plenty of batteries

Cooling? Very difficult. Where does the heat transfer to?

Latency? Highly variable.

Equipment upgrades and maintenance? Impossible.

Radiation shielding? Not free.

Decommissioning? Potentially dangerous!

Orbital maintenance? Gotta install engines on your datacenter and keep them fueled.

There's no upside, it's only downsides as far as I can tell.

kolbe · 2 months ago
Re: reliable energy. Even in low earth orbit, isn't sunlight plentiful? My layman's guess says it's in direct sun 80-95% of the time, with deterministic shade.
kolbe commented on Dubious Math in Infinite Jest (2009)   thehowlingfantods.com/dfw... · Posted by u/rafaepta
neuroelectron · 3 months ago
Has anyone actually read Infinite Jest in its entirety? I got about 50 pages in and I'm pretty sure I got the jist of it from that. The constant slog into minutia and clunky grammar made it very slow reading for me. There were some funny parts but overall the effort didn't feel worth it.

I tore through Gravity's Rainbow (mentioned in another thread).

kolbe · 3 months ago
Cool. We care. Keep talking.
kolbe commented on Dubious Math in Infinite Jest (2009)   thehowlingfantods.com/dfw... · Posted by u/rafaepta
eszed · 3 months ago
I associated Pemulis with Polonius based on the phonemic similarity of the names. I don't have the maths background to evaluate the mistakes, but agree that if intentional they "match" with the character's presentation in Hamlet.
kolbe · 3 months ago
Maybe a phonetic similarity with "pretentious" as well
kolbe commented on Beware of Fast-Math   simonbyrne.github.io/note... · Posted by u/blobcode
djrj477dhsnv · 3 months ago
Sure, string encodings are used for most APIs and ultra HFT may pattern match on the raw bytes, but for regular HFT if you're doing much math, it's going to be floating point math.
kolbe · 3 months ago
We might have different definitions of "HFT"
kolbe commented on Beware of Fast-Math   simonbyrne.github.io/note... · Posted by u/blobcode
usefulcat · 3 months ago
You can certainly make trading systems that work using floating point, but there are just so many fewer edge cases to consider when using fixed point.

With fixed point and at least 2 decimal places, 10.01 + 0.01 is always exactly equal to 10.02. But with FP you may end up with something like 10.0199999999, and then you have to be extra careful anywhere you convert that to a string that it doesn't get truncated to 10.01. That could be logging (not great but maybe not the end of the world if that goes wrong), or you could be generating an order message and then it is a real problem. And either way, you have to take care every time you do that, as opposed to solving the problem once at the source, in the way the value is represented.

> Using some kind of fixed point math would be entirely inappropriate for most HFT or scientific computing applications.

In the case of HFT, this would have to depend very greatly on the particulars. I know the systems I write are almost never limited by arithmetical operations, either FP or integer.

kolbe · 3 months ago
It depends on what you're doing. If your system is a linear regression on 30 features, you should probably use floating point. My recollection is fixed is prohibitively slower and with far less FOSS support.
kolbe commented on Beware of Fast-Math   simonbyrne.github.io/note... · Posted by u/blobcode
simonw · 3 months ago
I've been having an interesting challenge relating to this recently. I'm trying to calculate costs for LLM usage, but the amounts of money involved are so tiny. Gemini 1.5 Flash 8B is $0.0375 per million tokens!

Should I be running my accounting system on units of 10 billionths of a dollar?

kolbe · 3 months ago
I've used Auroa Units to do this. You can define the dollars dimension, and then all the nano-micro-whatever scale comes with.
kolbe commented on Beware of Fast-Math   simonbyrne.github.io/note... · Posted by u/blobcode
jksflkjl3jk3 · 3 months ago
Floating point math shouldn't be that scary. The rules are well defined in standards, and for many domains are the only realistic option for performance reasons.

I've spent most of my career writing trading systems that have executed 100's of billions of dollars worth of trades, and have never had any floating point related bugs.

Using some kind of fixed point math would be entirely inappropriate for most HFT or scientific computing applications.

kolbe · 3 months ago
All your price field messages are sent to the exchange and back via fixed point, so you are using fixed point for at least some of the process (unless you're targeting those few crypto exchanges that use fp prices).

If you need to be extremely fast (like fpga fast), you don't waste compute transforming their fixed point representation into floating.

kolbe commented on Ask HN: Share your AI prompt that stumps every model    · Posted by u/owendarko
kolbe · 4 months ago
Nice try, Sam
kolbe commented on Federal Government's letter to Harvard demanding changes [pdf]   harvard.edu/research-fund... · Posted by u/moelf
wredcoll · 4 months ago
I admire your willingness to argue that, because they didn't do the corrupt thing, they are in fact corrupt.
kolbe · 4 months ago
Using your constitutionally granted executive powers is pretty standard.
kolbe commented on Federal Government's letter to Harvard demanding changes [pdf]   harvard.edu/research-fund... · Posted by u/moelf
ajross · 4 months ago
Classic No-True-Scotsman here: "Oh, well, sure, they were prosecuted in contravention of my point above. But that means they wanted to prosecute them."

(It's also tautological: I mean, of course they wanted to prosecute them. They were criminals and prosecutors prosecute criminals, definitionally!)

(And also also, it's an Occam's violation: the simpler explanation is that they were just treated like criminals and not that they were double-negative enforcement actions by a corrupt regime.)

kolbe · 4 months ago
Did that sound clever in your head? Again, the head of the executive branch can quash any charge he wants. You're the one contending that a person doing X is evidence that they support not-X.

u/kolbe

KarmaCake day3228June 17, 2012View Original