ChainOfFools

The middle of the bell curve, which dominates the market, has a need for drool-proof interfaces that many of the sort who frequent HN and similar interest communities do not.

I have a family acquaintance who works at a fairly prominent hft shop in nyc. He's rather circumspect when I ask him about details of his job, which doesn't directly relate to trading but I get the impression he has to know quite a bit about how the various trade plans work, since he is deeply involved in maintaining the highly bespoke infra they run on.

After a few beers he'll sometimes start bringing up "customers purchasing order flow" from them, which apparently accounts for a significant part of their revenue. He's also indicated that this is not a practice unique to their shop but is fairly commonplace among companies that have highly advantageous (next-building or same-floor/dc equivalent latency) transport to various exchanges.

I assume, but am hesitant to ask directly, that this activity cannot actually be what it sounds like, but now I don't know.

I hope I didn't make it sound like it was easy, at least I don't think I said that anywhere. It doesn't really matter how hard something is to do (short of it being trivially proven impossible), it matters whether there's a good enough chance that the payoff exceeds the cost.

And actually there have been attempts to do it, I mentioned in an earlier version of my comment that Gene Amdahl had attemped to make WSE work something like 20 years ago, without success - but also without the clear profitability story of AI to attract the same mountains of cash being thrown around today.

What's surprising is not that it is hard, or that it's hard as fuck, but that given the potentially stratospheric rewards for success there have not been more attempts in this direction.

edit: I should have just checked their website instead of guessing. Apparently WSE has significant fabrication challenges, which makes what Cerebras has accomplished all the more impressive. But it is still surprising that no one else has attempted this in the HPC field.

I had guessed that Cerebras had made some trade-offs in process in order to make it work at scale, but then they aren't actually building these devices at scale (yet).

"What kinds of people operate tor exit nodes and why do they do it" is one of those questions that I know I'm not even supposed to admit being curious about, let alone ask, in the company of people who are most capable of accurately answering.

From a certain distance LessWrong looks like the kind of place that would appeal to someone like me, so in spite of some of the negative characterizations I heard I tried browsing it through the strongest steelman goggles I could find.

The experience mainly left me with a sober respect for Groucho Marx's about not joining clubs that would have me as a member.

Exactly the sort of take I hope to find every time I browse HN.

A thoughtful "what if" that prompts reflection on a topic in a fundamentally unique way, even if it doesn't readily suggest a resolution.

I've never heard anything to confirm this, but I've always assumed that this was a reference to the history of Ball Aerospace, with its improbable origin and evolution from a company that made glass jars and lids for grandma's rhubarb preserves.

I too confused art with craft for quite a long time. it's another framing of the difference between being interested in why versus being interested in how.

Sorry if I'm coming across as presumptuous or something, it's just surprising to find that modern hard drives are still using the same basic mechanism that I saw inside the washing machine-size drives my dad worked on 40 something years ago, that would almost walk themselves out of their mounts thrashing their giant head servos around.

What you and others are describing is strikes me the way that opening up the package of a modern memory chip and finding a fabric of millions of tiny magnetic cores would, rather than a silicon array of capacitor/transistor cells - that for some reason no fundamental rethinking of the problem has prevailed and thus the only developments in RAM for almost half a century is miniaturization of what was being done in the 1960's.

I would never have guessed how much thermal expansion had to be compensated for in modern hard drives, I would have assumed they were built such that no degree of precision that required accomodating changes in physical parameters was attempted, and/or that materials science had found an ideal set of alloys for the case, the platters, the magnets, arms etc, that all behave in a predictable way under a given thermal map, so that addressing the surface was nearly always a deterministic process.

Have there been attempts to use active cooling/heating (i.e. thermal sensors combined with piezoelectric effect elements embedded in the housing) to maintain a precise, consistent reference internal operating temperature, as a means of eliminating the need to accomodate thermal-induced drift in tolerances?

I don't know I keep getting answers to different proposals than the one that I have made, all with a significant detail changed so that the answer makes sense and the proposal sounds absurd.

In this case, I don't know how the impression could be gained that I was suggesting mounting 100 or so individual assemblies of the very same read write head currently used on mechanical drives, each with its own separate wiring harness.

Obviously, yes that would substantially increase the cost and the mass and everything else, you're right. Thanks for setting me straight about the impracticality of very different solution than the one I described, which suggested the heads could be manufactured as a single integrated unit, the way every other matrix of active elements (OLED displays, memory cells, someone else mentioned mems, etc.) is made, which might require two additional wires for selection signalling, if that, depending on what could be multiplexed. In exchange for this weight and complexity you get rid of one, possibly two extra servo joints, one possibly two extra armatures, plus all the wiring and additional control logic required for positioning this very delicate articulated assembly.

Now, if this array cannot be manufactured because no current solid state process exists that can reproduce the characteristics of a wound coil, duplicated a hundred times in a linear array of cells on silicon or some other substrate, that's an obstacle I can reason about and accept as a plausible dead end.

What would be the advantage of having different sector and track layouts for different platters on the same spindle, with the same servo addressing all of them? Are platters binned the same way that processors are?

Back when I lived in Portland 20+ years ago, just as it was starting to turn into the version of itself that would be sent up in Portlandia, I used to tell relatives back east that culturally Oregon is to California what California is to the rest of the country.

Not sure how true that remains these days, it's been a while since I've been up there.

I remember someone explaining this to me years ago when IOmega released those removable Bernoulli drive cartridges. The (for the time) high densities were possible because even though the recording medium was a flexible bit of plastic, the head was designed to draw surface of the media up to itself using the namesake effect, rather than relying entirely om precision machine tolerances. And this effect was dynamically self limiting, such that there could not be a head crash as long is the unit wasnt disturbed during operation.

What I did not know is that this is still and effect that is relied upon in modern, ultra high precision, fixed medium drives.

The article does mention that this is a complication particular to SMR drives, but I was thinking about this not necessarily as a means of reaching higher density storage, but more reliable and perhaps higher performance solutions that would fall somewhere between the compromises of an SSD and a mechanical drive.

It also seems possible that instead of a single super high density strip of heads which may be impossible to manufacture, that instead a series of much lower density array strips could be mounted in n ranks, each rank offset from the predecessor by n/(distance between heads in each strip).

I assume this is not an insurmountable engineering, but that someone has already had this idea or something similar to it, and after running the numbers found it doesn't deliver enough of an advantage over the conventional design to be worth exploring further.

What if the bar were able to travel linerarly via a voice coil, and had hundreds of heads, but the bar was able to shift in a linear fashion only about a micron back and forth in increments of thousandths of a micron.

Wouldn't that get you to your millions of heads of effective track coverage, without all the complexity of having to move two or three different hinges on several different actuators sweeping the entire arc? Naively speaking it seems like you could mount such a bar even closer to the surface of the track since there is no chance of a head crash, as it could be supported at both ends of its mounting.

Surely the entire armature that moves an articulated set of actuator assemblies plus the head itself would be heavier and more cumbersome and failure-proneto move than a linearly-fixed rail.

Obviously someone has thought of this before me so there's a good reason for it, but track density alone can't be it.

I wonder why drives still use mechanical actuators to fling a single read write head back and forth across the surface, rather than a bar fixed in place that spans entire radius of the writable surface, with an addressable strip of r/w heads that runs the length of it.

I assume it's because the actual read-write head itself must among the most expensive parts to manufacture, but is there no photo mask approach to this that can manufacture such a head array (or staggered series of them if there is some interference problem that prevents putting them side by side in a single strip) the same way but processor dies are made?

C.S. Lewis condensed this even further, as the "sudden perception of incongruity."

It was a good time to be buying Intel when they were naming their chips after Oregon cities.

The studio I worked at during that time actually did have a CPU slot based memory extension that can handle I believe up to 256 Mb, this would have been around 92 or 93, but I'm not sure how early it was offered on the market that's just when I started there and it was already in the shop.

I don't recall the name of it though but I remember that it was a peculiar PCB design, with part of it resembling a breadboard. I think the name started with Ex, like Excelsior or Excalibur or something like that.

Listed in that wiki, along with the much older Picojava

What is the source of this? Many years ago I wrote an honors essay for some undergrad class that built on the same observation, although I needed to run with it for a dozen pages or so to satisfy page count expectations.

I looked at the Alice camera, and immediately had to suppress the urge to sign up for the kickstarter while I took a step back to consider that this will end up in the tech junk drawer after a few novelty outings.

It fails the same 'one extra thing to carry around and keep protected while not in use, which is most of the time' test as small mirrorless point and shoots and micro four thirds interchangeable lens cameras ( speaking as a long time OM-D user and enthusiast)

And if it's possible to affix it to my phone it will also get left home sooner rather than later, because now all of my phone accessories, mag safe chargers, car mounts, cases, etc no longer fit, which makes it cumbersome to carry around and use as a phone.

While we're on the subject, how about how the position of the headlights on these vehicles that aims squarely at the side and rear view mirrors of passenger cars, distracting and dazzling the drivers for no reason other than to intimidate and discourage them from being in the very important way of these vehicles' drivers.

and even worse, the headlamps blast the retinas of infants in rear facing car seats, who don't have the option to flip their mirror to the dim setting, or even turn their head away from the glare.

I have profound contempt for people who buy and enjoy hostility optimized vehicles like thesd, unless absolutely compelled to do so for work.

But sticking to the familiar crowd-pleasing members of that sequence to make the joke stick, knowing that even on this site working in poor neglected uracil would be trying too hard

tax writeoffs

so much human potential, natural resources, and anxiety wasted on obsessive pursuit of diddling a few special nerve endings, heaped in a mountain of self-serving social pecking order mythology and ritualistic mystery.

I'm not sure I was clear, or if the manner in which I was attempting to frame my response using the context of the parent post worked the way I thought it would.

But what I mean is that 10 minutes would be perhaps the approximate boundary where I feel comfortable holding the floor engaging in curious but uninformed speculation, and the sense of fraud that I am possibly wasting everyone's time by continuing to speculate begins to encroach.

If I care about a subject enough I think like most people I don't have problem holding forth on it, free of supporting notes, for 2 or 3 hours if circumstances (and the extent of my command of the material, and the patience of my audience) would allow.

> about my ability to speak for 10 minutes about something without notes.

I'm not sure how common this sentiment is, but I would feel extraordinarily uncomfortable -to the point of feeling a bit like a fraud - if I were to speak about something continuously for 10 minutes (at a high degree of entropy, rather than just taking glancing stabs at the same observation from multiple angles) _unless_ I could do it without notes. If I could not do so I don't think I would even attempt to participate in a conversation on that subject, feeling as though I had nothing useful to contribute to the conversation.