6 ms·

I don’t know how well it holds today but for some time it was known that running certain computations on existing hardware would take longer than waiting for ne

I don’t know how well it holds today but for some time it was known that running certain computations on existing hardware would take longer than waiting for new hardware and running when available.

seeknotfind 3y ago
If hardware next year is X times better (e.g. even 1.01 or 1% better) than this year, and you have a computation that takes T time today, then next year, it'll take T/X time. So waiting will take 1 + T/X years if time unit is years. So the condition you want is 1+T/X < T. This equation has solutions for given X where X is an improvement, so as long as there is any improvement, it's always true waiting to start large enough computations will be faster. Though even faster will be doing part of the computation now and then switching to new hardware later, so it's a false dichotomy.
- MaulingMonkey 3y ago
  > Though even faster will be doing part of the computation now and then switching to new hardware later Not necessairly. This still costs: • Programmer/development time to implement save/restore/transfer • Time on new hardware, bottlenecked by old hardware, restoring a partial computation from old disks or networks You're not going to waste time restoring partial calculations for anything from an Amiga cluster for time saving purpouses. Additionally, this scheme ties up hardware that then can't be used for "cost effective to finish on current hardware" calculations.
- LegionMammal978 3y ago
  > This equation has solutions for given X where X is an improvement, so as long as there is any improvement, it's always true waiting to start large enough computations will be faster. Though this does assume that X is a constant, or at least bounded below by a constant. If hardware performance improved up to an asymptote, then there would still be nonzero improvement, but it might not be enough for waiting to ever be worth it.
  - seeknotfind 3y ago
    As "If hardware next year is X times better (e.g. even 1.01 or 1% better) than this year" highlights X is a constant as a simplifying assumption, I'd have expected you to say "As this assumes that X is a constant" not "Though this does assume that X is a constant". So, I'm not sure what your disagreement is. If your disagreement is that a constant is not appropriate here, consider the interpretation in this comparison of running a program on a slower computer A and then a faster computer B. There would be a constant difference in performance between these two computers, assuming they are in working order. So, taking the model with a single constant is appropriate for this example. If you are saying the performance improvement is bounded below by a constant, I would ask you, what is the domain of this function? Time? So we would be talking about continuously moving a computation between different computers? The only line here is a best fit line, emergent data, so I don't understand how this could be a preferred way to talk about the situation (the alternate to an assumption), because this is suggesting the emergent structure with nice continuity features is a preferred fundamental understanding of the situation, but it's not. Then, where you are talking about hardware performance improving up to a (assuming horizontal) asymptote. I guess this means "If hardware performance increase becomes marginal[1], there is a nonzero improvement." Or in other words, "If hardware performance increase is marginal, there is a marginal [performance] increase". Performance and improvement are both rates of change, so this is tautological. Finally, you state that waiting for such a marginal near-zero performance increase isn't worth it. I think most people would agree this is obvious if said in simpler terms. However, this is still not disagreeing with me, because I never suggested waiting was worth it. So, what's the disagreement? [1] which is well-established not to be the case, so I don't think this is a relevant case to the interesting factoid about waiting to start computation
    - LegionMammal978 3y ago
      My apologies, I misinterpreted you as talking about waiting for many years (given a sufficiently large task) for performance to continue increasing, since this thread started talking about Moore's Law. I have no disagreement in the single-year case you were actually talking about.
deleted 3y ago
[deleted]
gorgoiler 3y ago
My life archive is available to my heirs and successors as long as they know the LUKS password for any of the numerous storage devices I leave behind. It’s risky though — the passwords aren’t known to them yet and one logistical slip up means the disk may be unusable. That is, however, until some point in the future when they will have a computer powerful enough to just break the key and feast upon my cat photos, tax returns, and other exciting ephemera. Similarly my encrypted internet traffic might be private today but if it’s being logged then it’s only a matter of time before it will be completely visible to the authorities. I probably average ~10Mbps of traffic which is ~50TB/year, or $100 of storage. You could cut that price by 10% if you blacklisted the Netflix traffic, and drop it to 1% if you whitelisted only the email and IM traffic. Either way, one day they’ll know everything.
- cdchn 3y ago
  Using what kind of media?
- londons_explore 3y ago
  If the contents of your computer is anything like the contents of most old people's attics, there is a good chance your descendants really don't want to go through all of it. They'll just chuck it in the trash without even opening it. Turns out the next generation has their own life to worry about, and doesn't care much for their ancestors' stuff (unless it's money... they love money...).
  - rytis 3y ago
    What about that long forgotten BTC wallet?
    - Mtinie 3y ago
      Without a private key that is readily accessible? Worthless,
      - lebed2045 3y ago
financypants 3y ago
I wonder if this same law applies to distance satellites like Voyager get away from earth. Like we sent out voyager 46 years ago, but in 100 years, we will send out another satellite that will very quickly catch up to Voyager and outpace it
- mcmoor 3y ago
  There's certainly some people who're troubled with this problem https://en.m.wikipedia.org/wiki/Interstellar_travel#Wait_calculation https://en.m.wikipedia.org/wiki/Interstellar_travel#Wait_cal... https://tvtropes.org/pmwiki/pmwiki.php/Main/LightspeedLeapfrog https://tvtropes.org/pmwiki/pmwiki.php/Main/LightspeedLeapfr...
  - financypants 3y ago
    Thanks for this. I’ve been thinking about “lightspeed leapfrog” for many years but never searched it up!
- a1o 3y ago
  But maybe we can only build this new probe that will outpace it with information with gathered from the original probe.
- idiotsecant 3y ago
  Very long distance spaceflight like this is still basically only power d by gravity slingshot maneuvers where we steal an infinitesimal amount of inertia from planets to give a spacecraft some velocity. Voyager was launched during pretty favorable gravitational assist conditions, so unless we dramatically improve delta v and isp in the spacecraft or get a better configuration, probably not.
kqr 3y ago
I don't know about that, but there was also the idea that optimising the code would take longer than waiting for hardware to catch up – this was known as "the free lunch".
dcminter 3y ago
I was working with an optimisation problem based around cplex a few years ago that took about 5 minutes to complete - at the time I worked out that if we'd started the optimisation on a machine 10 years prior, it would have been quicker to just wait until the present day (of this story) and then use the code we were writing because improvements in the algorithm and in the hardware added up to a million-fold improvement in performance! If I remember the timelines correctly I think the original version would still have been running today even.
JKCalhoun 3y ago
That sounds like the space pioneers that set out for Alpha Centauri on a multi-generational voyage only to be surpassed by faster spacecraft half way there.

seeknotfind 3y ago

If hardware next year is X times better (e.g. even 1.01 or 1% better) than this year, and you have a computation that takes T time today, then next year, it'll take T/X time. So waiting will take 1 + T/X years if time unit is years. So the condition you want is 1+T/X < T. This equation has solutions for given X where X is an improvement, so as long as there is any improvement, it's always true waiting to start large enough computations will be faster. Though even faster will be doing part of the computation now and then switching to new hardware later, so it's a false dichotomy.

MaulingMonkey 3y ago
> Though even faster will be doing part of the computation now and then switching to new hardware later Not necessairly. This still costs: • Programmer/development time to implement save/restore/transfer • Time on new hardware, bottlenecked by old hardware, restoring a partial computation from old disks or networks You're not going to waste time restoring partial calculations for anything from an Amiga cluster for time saving purpouses. Additionally, this scheme ties up hardware that then can't be used for "cost effective to finish on current hardware" calculations.
LegionMammal978 3y ago
> This equation has solutions for given X where X is an improvement, so as long as there is any improvement, it's always true waiting to start large enough computations will be faster. Though this does assume that X is a constant, or at least bounded below by a constant. If hardware performance improved up to an asymptote, then there would still be nonzero improvement, but it might not be enough for waiting to ever be worth it.
- seeknotfind 3y ago
  As "If hardware next year is X times better (e.g. even 1.01 or 1% better) than this year" highlights X is a constant as a simplifying assumption, I'd have expected you to say "As this assumes that X is a constant" not "Though this does assume that X is a constant". So, I'm not sure what your disagreement is. If your disagreement is that a constant is not appropriate here, consider the interpretation in this comparison of running a program on a slower computer A and then a faster computer B. There would be a constant difference in performance between these two computers, assuming they are in working order. So, taking the model with a single constant is appropriate for this example. If you are saying the performance improvement is bounded below by a constant, I would ask you, what is the domain of this function? Time? So we would be talking about continuously moving a computation between different computers? The only line here is a best fit line, emergent data, so I don't understand how this could be a preferred way to talk about the situation (the alternate to an assumption), because this is suggesting the emergent structure with nice continuity features is a preferred fundamental understanding of the situation, but it's not. Then, where you are talking about hardware performance improving up to a (assuming horizontal) asymptote. I guess this means "If hardware performance increase becomes marginal[1], there is a nonzero improvement." Or in other words, "If hardware performance increase is marginal, there is a marginal [performance] increase". Performance and improvement are both rates of change, so this is tautological. Finally, you state that waiting for such a marginal near-zero performance increase isn't worth it. I think most people would agree this is obvious if said in simpler terms. However, this is still not disagreeing with me, because I never suggested waiting was worth it. So, what's the disagreement? [1] which is well-established not to be the case, so I don't think this is a relevant case to the interesting factoid about waiting to start computation
  - LegionMammal978 3y ago
    My apologies, I misinterpreted you as talking about waiting for many years (given a sufficiently large task) for performance to continue increasing, since this thread started talking about Moore's Law. I have no disagreement in the single-year case you were actually talking about.

deleted 3y ago

[deleted]

gorgoiler 3y ago

My life archive is available to my heirs and successors as long as they know the LUKS password for any of the numerous storage devices I leave behind. It’s risky though — the passwords aren’t known to them yet and one logistical slip up means the disk may be unusable. That is, however, until some point in the future when they will have a computer powerful enough to just break the key and feast upon my cat photos, tax returns, and other exciting ephemera. Similarly my encrypted internet traffic might be private today but if it’s being logged then it’s only a matter of time before it will be completely visible to the authorities. I probably average ~10Mbps of traffic which is ~50TB/year, or $100 of storage. You could cut that price by 10% if you blacklisted the Netflix traffic, and drop it to 1% if you whitelisted only the email and IM traffic. Either way, one day they’ll know everything.

cdchn 3y ago
Using what kind of media?
londons_explore 3y ago
If the contents of your computer is anything like the contents of most old people's attics, there is a good chance your descendants really don't want to go through all of it. They'll just chuck it in the trash without even opening it. Turns out the next generation has their own life to worry about, and doesn't care much for their ancestors' stuff (unless it's money... they love money...).
- rytis 3y ago
  What about that long forgotten BTC wallet?
  - Mtinie 3y ago
    Without a private key that is readily accessible? Worthless,
    - lebed2045 3y ago

financypants 3y ago

I wonder if this same law applies to distance satellites like Voyager get away from earth. Like we sent out voyager 46 years ago, but in 100 years, we will send out another satellite that will very quickly catch up to Voyager and outpace it

mcmoor 3y ago
There's certainly some people who're troubled with this problem https://en.m.wikipedia.org/wiki/Interstellar_travel#Wait_calculation https://en.m.wikipedia.org/wiki/Interstellar_travel#Wait_cal... https://tvtropes.org/pmwiki/pmwiki.php/Main/LightspeedLeapfrog https://tvtropes.org/pmwiki/pmwiki.php/Main/LightspeedLeapfr...
- financypants 3y ago
  Thanks for this. I’ve been thinking about “lightspeed leapfrog” for many years but never searched it up!
a1o 3y ago
But maybe we can only build this new probe that will outpace it with information with gathered from the original probe.
idiotsecant 3y ago
Very long distance spaceflight like this is still basically only power d by gravity slingshot maneuvers where we steal an infinitesimal amount of inertia from planets to give a spacecraft some velocity. Voyager was launched during pretty favorable gravitational assist conditions, so unless we dramatically improve delta v and isp in the spacecraft or get a better configuration, probably not.

kqr 3y ago

I don't know about that, but there was also the idea that optimising the code would take longer than waiting for hardware to catch up – this was known as "the free lunch".

dcminter 3y ago

I was working with an optimisation problem based around cplex a few years ago that took about 5 minutes to complete - at the time I worked out that if we'd started the optimisation on a machine 10 years prior, it would have been quicker to just wait until the present day (of this story) and then use the code we were writing because improvements in the algorithm and in the hardware added up to a million-fold improvement in performance! If I remember the timelines correctly I think the original version would still have been running today even.

JKCalhoun 3y ago

That sounds like the space pioneers that set out for Alpha Centauri on a multi-generational voyage only to be surpassed by faster spacecraft half way there.