[HN Gopher] How much load can be served from 1m2 of sunlight
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How much load can be served from 1m2 of sunlight
Author : forkfork
Score : 138 points
Date : 2021-11-02 06:39 UTC (1 days ago)
(HTM) web link (medium.com)
(TXT) w3m dump (medium.com)
| alacritas0 wrote:
| To see another attempt of serving a webpage off of solar power:
| take a look at https://solar.lowtechmagazine.com/about.html -- it
| has techniques I find pretty unique for conserving power. All the
| images are rasterized in order to reduce page size among other
| things.
| sparsely wrote:
| Cool idea, the numbers in this blog post are very much a worst
| case scenario outside of running the entire process on 1080 GPU
| or something though
| turtlebits wrote:
| The title is a bit misleading as it's specific to the OPs setup
| (which is quite inefficient).
|
| Would have liked to to see numbers of how much power is actually
| being output by the panel, and a shunt on the battery to see
| accurate consumption.
| ananonymoususer wrote:
| I did this 20 years ago and ran the server for about 10 years. I
| down-scaled the server hardware when I transitioned to solar, but
| soon discovered that the low-power server just could not keep up
| with the demand. I upgraded to something in the middle that could
| handle a decent number of web users while still not using all the
| solar. I had 1280W of panels (16x80), a 1500W inverter, and three
| deep-cycle 12V 50AH batteries.
|
| The remnants of the system can still be seen here:
| http://jsl.com/solar
| the-dude wrote:
| Link is dead. So how much did the upgraded server draw?
| louwrentius wrote:
| Site seems down?
|
| https://web.archive.org/web/20160401215358/http://www.jsl.co...
| junon wrote:
| Probably hugged a bit, it works for me.
| masklinn wrote:
| What was the demand? 1200W seems like a lot,
| https://solar.lowtechmagazine.com runs on a 50W solar panel
| with a 168W lead-acid battery (non-deep-cycle so effectively
| 84Wh).
|
| However it gets to have fully static content, and benefits from
| relatively modern hardware: for under 2W it runs on a dual-core
| 1GHz ARM with 1GB RAM (and a 16GB SD card but it doesn't use
| anywhere near 16GB).
| lazide wrote:
| Keep in mind, 1200w would be maximum peak power consumption
| most likely (as you need to size for that, depending on how
| many seconds the chosen inverter could sustain above peak). A
| good sized gaming rig would require that type of peak
| consumption, even if 99% of the time it's consumption maybe
| be zero.
| Robotbeat wrote:
| Of course, you can juice this a bit by doing two things: 1) using
| concentrating photovoltaics with multifunction solar cells to
| achieve ~30-40% efficiency. (This requires active cooling.) 2)
| use 2 axis tracking. 3) solar cells on the back of your array.
| (Bifacial solar arrays do this in an integrated manner but aren't
| concentrating.)
|
| These three together give you on the order of a factor of 3
| greater total energy. (Note: concentrating buys you about 20%
| greater raw efficiency BUT means capturing diffuse light
| basically doesn't happen. Might be better off with a non-
| concentrating bifacial multijunction panel that is still two axis
| tracked. Concentrators can still help financially because
| multijunction solar panels are EXPENSIVE.)
|
| Also, if your laptop already has a beefy battery, you don't need
| a separate battery. You'll need a custom MPPT with the right
| output voltage, but you could hook it straight into your laptop.
| That saves money (potentially) and a lot of inefficiency.
| rzimmerman wrote:
| It would be interesting to set up a server/PC that throttled The
| CPUs/GPUs by power use rather than thermal readings. It's
| analogous to the burst credit system used on some EC2 instances,
| but it would be a cool kernel or hardware feature for devices
| that are completely solar powered.
| tantalor wrote:
| What is the bottleneck is this system?
| dotancohen wrote:
| Theoretical: Amount of energy in sunlight.
|
| Practical: The creativity of the engineer building it.
| daneel_w wrote:
| The detour of 12 volts -> mains voltage -> back to low voltage
| is a big one, for starters.
| lazide wrote:
| Also what most folks end up doing for convenience. It can be
| surprisingly inconvenient and expensive to source a power
| supply at 12v/24v/48v or whatever, and battery voltages are
| always nominal (think barely approximate), so you can't get
| clean power regulated directly sufficient for running a
| computer. For instance, "12v" automotive voltages can vary
| from 8v to 15v during normal vehicle operation - like
| starting the vehicle, charging at full tilt on the highway,
| etc. a full battery can provide 13.7-14.8v depending on
| chemistry too.
| louwrentius wrote:
| I run my static blog on a Raspberry Pi3B+ Powered by solar [0]
| and it doesn't even flinch when it is hit by hacker news.
|
| It idles at around 3.1 watts and that power usage includes a step
| down converter from 12 volt to 5 volt.
|
| A bunch of lead acid batteries of various capacities provide
| backup. Lead acid is a terrible choice because charge times are
| long, but it is sufficient for now.
|
| Just see it as performance art.
|
| [0]: https://louwrentius.com/this-blog-is-now-running-on-solar-
| po...
| mywittyname wrote:
| Is there a name for this effect in an abstract sense? I see it
| pop up a lot where the gains from scaling are super-linear to the
| scale itself. Or is it just called "economies of scale".
| gberger wrote:
| Marginal cost of production? If we take "energy consumption" to
| mean "cost", and "serving web requests" to mean "production",
| then your fixed cost is the idle energy load, and the marginal
| cost is how much more energy you would need to serve an
| additional request.
| londons_explore wrote:
| The authors "92%" efficiency calculations will be with the
| inverter and power supply at high load.
|
| When drawing only 20 watts, I expect you'll see more like 80%
| efficiency, and maybe as low as 50%.
| forkfork wrote:
| I'll try to measure this. I guess I need to purchase a shunt.
| londons_explore wrote:
| If you have a regular $3 multimeter, it should be able to
| measure current and voltage between the battery and inverter.
| Then just multiply. _double check you 're on the right mode
| and using the right socket on the meter before connecting, or
| you'll get a big bang!_.
|
| For the AC side, it's much harder to measure - typical
| inverters have rather imperfect AC outputs, and unless you
| have a rather expensive multimeter you won't get an accurate
| power measurement. A kill-o-watt will probably be okay for a
| rough measurement, but there might well be a +- 20% error...
| ketralnis wrote:
| The armchairs here are all great. If they used a raspberry pi and
| rewrote their javascript in ARM assembly and reinvented a more
| power-efficient compression algorithm and solved your favourite
| problem of serving static pages instead of the problem they
| actually want to solve, they could maybe get more instructions
| per watt.
|
| But really, I'm glad that they're actually doing it instead of
| talking about doing it and spending all of their time musing
| about _what if_ they did this other thing instead. This looks
| great.
| bo1024 wrote:
| I was confused about the "doing it" part. I see that they have
| all the materials and got some numbers like average power
| consumption, but they didn't seem to actually set it up and see
| how it worked?
| forkfork wrote:
| Author here - I'm learning as I go. I thought of talking a
| out the actual sunlight starting at closer to 1300W and
| losing efficiency at each step, but I don't get have the
| right tools to do that properly.
|
| I'd def love to hear your suggestions though as I continue to
| iterate this one.
| ctdonath wrote:
| I regularly work outside during summer, powering a MacBook Pro
| exclusively by sunlight (panel about 1m^2). For a few hours I can
| get a good 50+ watts, buffering thru a 100Wh battery. Keeping the
| load typically around 10-15 watts isn't hard, so long as paying
| attention.
|
| Of note, I persuaded Atlassian to remove the (rather nice)
| animated clouds from their "you have been logged out" web page
| because it pulled 30 watts (even when web page was hidden).
| Running on solar/battery exclusively, that was a problem; kudos
| to them for acting on it.
| turtlebits wrote:
| 50W seems rather low for a a 1m^2 panel. I have some older 250W
| panels (1.6m^2) and get around 220W in the summer.
|
| Also, how are you measuring a 10-15W load? When plugged in, the
| charger is going to pull it's rated load from your battery bank
| (I'm seeing ~84W including inverter losses).
| ctdonath wrote:
| System peaks around 57W, with battery charge rate limits and
| frequent environmental disruptions (clouds, angles, etc).
|
| Battery (Goal Zero Sherpa 100AC) shows output load. Lowest
| draw on MacBook Pro 15" is 7W, usually idling 10-15W, pulls
| about 50W when charging.
| Amorymeltzer wrote:
| The point of the piece is at the bottom:
|
| >By increasing our utilization rate, we have increased power
| efficiency by a factor of 6.
|
| >Economies of scale are more important than intuition would
| suggest for efficiently serving requests
| jeffbee wrote:
| This is an aburdly bad result, mostly caused by the questionable
| 14W base power draw, but also due to the questionable choice of
| gzip compression, which is not exactly on the frontier of
| compression technology. Even zlib-deflate would decompress twice
| as fast at the same size ratios, but something like lz4 or snappy
| would be an order of magnitude less CPU time cost for similar
| compressed size.
|
| The real way to have an energy-efficient service is to amortize
| away your idle usage and all of these inefficient conversion
| steps by just hosting your junk on App Engine.
| forkfork wrote:
| I'll iterate towards a good solution. This was a somewhat
| realistic but naive solution (I have customers doing largely
| what I've described in the article).
|
| If I could find a way to encourage people to run their work in
| a power efficient way using economies of scale from this
| series, I would be terribly happy.
|
| Interestingly I suspect public-cloud FaaS solutions (e.g. AWS
| Lambda) will achieve highest utilisation rates due to high rate
| of CPU sharing - but I'm a long way off from showing that with
| data.
| evancoop wrote:
| One question of great relevance is the change in the statistic
| implied by the article's title over the past couple decades, and
| the projected change in the decades to come. Is this Moore's-law-
| esque? If so, eventually, these concerns will be trivial. Is an
| asymptote approaching? If so, this metric becomes increasing
| relevant and crucial.
| ed25519FUUU wrote:
| > _12v to 240v inverter_
|
| Can someone explain this part of his equation? What's he doing
| with 240v? Or maybe he meant 24v for charging the laptop?
| ketralnis wrote:
| He's in Australia which uses 240v mains power. He's using an
| inverter to connect his regular old laptop charger plug.
| philipkglass wrote:
| He's using a household solar inverter designed to convert low
| voltage DC to AC at standard wall socket voltage. It's not the
| most efficient approach, as noted in other comments, but it's
| an easy approach since these inverters are common and a
| laptop's power supply is already set up to plug into a wall
| socket.
| forkfork wrote:
| Yep! Inefficient, but it is what I have, and there is no risk
| to frying my moderately expensive laptop which I hope to keep
| running for many years.
| danuker wrote:
| Rather than inverting 12V DC to 240V AC and back, you could skip
| a step and use a laptop car charger, converting 12V DC straight
| to ~20V DC.
| na85 wrote:
| Don't DC-DC transformers use AC internally?
| reportingsjr wrote:
| In power electronics terms, no. AC is defined as waveforms
| that have an average value of zero, which you won't find in a
| DC-DC converter.
|
| That wasn't the point of OP though. Their point was that you
| could remove some inefficient steps to improve the overall
| efficiency and energy capture of the system.
| 0xfaded wrote:
| Not necessarily. See voltage doubler:
|
| https://en.m.wikipedia.org/wiki/Voltage_doubler
| jmrm wrote:
| If you want electrical isolation between the input and the
| output, they use AC in the middle to achieve that, but if you
| don't want isolation, you could use a boost DC converter:
| https://en.wikipedia.org/wiki/Boost_converter
| nomel wrote:
| Which use alternating _voltage_ , across the inductor, but
| the current is always (with load) positive. Neat!
| dreamcompiler wrote:
| Yes but it's kHz-range PWM square-wave AC; there's no 60Hz
| sinewave involved. Converting to/from a 60Hz sinewave
| requires extra circuitry that decreases efficiency. And in
| this application a 60Hz AC sinewave serves no useful purpose.
| jagger27 wrote:
| The point is to remove the laptop power brick. Let's say the
| laptop charger is 90% efficient, which is fairly typical. The
| post claims their 12VDC to 240VAC inverter is 92% efficient.
| A 12VDC to 20VDC voltage booster would only have to be >83%
| efficient to beat that setup.
| colejohnson66 wrote:
| Which isn't that hard for a switch mode converter. Those
| are usually 85% or more IIRC.
| jmrm wrote:
| That's true. If both conversions are 90% efficient, we are
| talking a 81% efficiency in both process, wasting nearly 1/5 of
| the energy used. That's not good at all.
| coding123 wrote:
| I did this for a year on my previous macbook and it destroyed
| the battery. The inverter creates cleaner power. Good luck
| finding a quality one that can handle the voltage changes from
| 14.6 -> ~10.5 the battery is going to spit out with the MPPT
| attached..
| nomel wrote:
| Maintaining a regulated voltage with input voltage changes is
| a primary feature of a DC-DC converter, like a boost
| converter. With a buck-boost converter, you can maintain a
| regulated voltage when the input voltage goes above or below
| the output voltage.
| bee_rider wrote:
| I wonder how much the efficiency loss from a laptop car charger
| would compare to just using something like a NUC -- IIRC some
| of their models have really wide input voltage ranges (12v-20v
| or something like that, depends on the model). The laptop is
| really just bringing a battery, compared to a NUC, for this
| application, and they are going
| panel->regulator->battery->converter anyway so the laptop
| battery seems redundant.
| genewitch wrote:
| Odroid H1/H2 iirc can run from like 10-22VDC, the issue is
| finding a solar panel that has an open circuit voltage less
| than 22V. I found a buck-boost that works with my old laptop
| and a "car charger" with my admittedly oddball solar panels,
| so this is possibly, but takes time shopping and reading
| specifications.
| bee_rider wrote:
| The design in the article (which does seem to have some
| redundant parts, so...) instead goes:
|
| Panel -> regulator -> battery -> inverter -> laptop
|
| So, the voltage of the panel shouldn't really matter too
| much, I think (I mean, you size the regulator input range
| as appropriate). OTOH, solar panels are a little magical
| from my point of view, so maybe that regulator ought to be
| replaced by some solarpanel specific thing, which might be
| more constricting.
| lazide wrote:
| It isn't a regulator, it's a charger - depending on the
| design, you can get even higher voltage spikes. 12V
| batteries charge at 13-14V, but most chargers design for
| lead acid can get away with reallly really noisy voltage
| transients due to the way lead acid works. It's a pretty
| insensitive chemistry and dampens them normally.
|
| Some chargers with 'equalize' or even worse
| 'desulphation' can intentionally go even higher in
| voltage than normal charging voltages.
|
| So basically 'if you just assume it wouldn't kill your
| laptop to directly connect it, you're playing Russian
| roulette with your laptop'.
|
| With a decent spec sheet (and oscilloscope) to verify
| nothing too crazy that the charger is doing, some decent
| power filtering capacitors, and good DC-DC power supply
| you'd be fine though.
| Maakuth wrote:
| That's not a way to get good power out of the PV panel,
| though. An MPPT tracker (https://en.m.wikipedia.org/wiki/Ma
| ximum_power_point_tracking) is needed to get the best
| results, and the room for improvement is indeed
| substantial. There are good and cheap chinese ones
| available, such as Epever brand.
| londons_explore wrote:
| A very cheap, bad-practice, but effective solution is to run
| the inverter to AC and back to DC again with the ATX power
| supply, but to connect the 12V from the battery _direct_ to the
| motherboards 12v rail.
|
| The motherboard uses most of its power from the 12v rail, and
| due to the galvanic isolation in the ATX power supply, it
| should be safe to do.
|
| The 12VDC from the battery may not be in spec for the
| motherboard, but typically they'll work anyway.
| kempbellt wrote:
| It's also worth noting that many "12 volt" DC batteries do
| not store and output at _exactly_ 12 volts.
|
| Depending on the tolerances of your board, you might want to
| throw a buck converter in the circuit and set the output
| voltage set to exactly 12 volts to account for any potential
| over-voltage coming from the battery/panel setup.
|
| They are pretty cheap if you want to DIY (7 for $10 on
| Amazon). Worth the peace of mind, imo.
|
| I imagine this is what most car-laptop chargers are, but with
| branded packaging.
| ananonymoususer wrote:
| You could also use a desktop with one of these ATX power
| supplies that runs on 12VDC instead of 120/240VAC:
|
| https://www.cartft.com/catalog/il/2302
| cogman10 wrote:
| Looking at the size of this thing, I sort of doubt it's much
| more efficient than doing a DC->AC->DC conversion. In fact,
| I'll betcha that's exactly what's happening inside this beast
| to both get the right voltages and stabilize them.
| consumer451 wrote:
| Wow, I was not expecting that price! Is this just a rare item
| or is there something particularity expensive inside it?
| brudgers wrote:
| How much labor does it save?
|
| How much trouble shooting does it eliminate?
|
| How much experience does it make unnecessary?
|
| Or to put it another way, at the point where 1500w of 12v
| source computer power supply makes sense, the price is not
| unreasonable.
| tyrells wrote:
| Definitely are cheaper options too: https://www.mini-
| box.com/picoPSU-160-XT
| fragmede wrote:
| It's not a mass-market item so they're expensive to begin
| with, but I'd bet its current price is a function of the
| chip shortage we've been hearing about.
| dreamcompiler wrote:
| Or use a 20v MPPT with a higher-voltage panel (or two smaller
| panels in series) and skip the car charger.
| sfblah wrote:
| Wouldn't the battery voltage be the controlling factor here?
| Probably could go with 2 12v batteries in series? I assume a
| 20v laptop charger is fine with that.
| lazide wrote:
| You really can't assume much of anything here frankly.
| Voltages here are nominal, and open circuit voltages can be
| quite high, or when under load can drop quite a bit. MPPT
| charger will attempt to maintain and output voltage within
| it's target range, but voltage transients and ripple can be
| a problem - they aren't designed as a live power supply,
| they are design to charge huge energy sinks with specific
| chemistries (aka batteries), so they usually cut corners
| that would matter in this case but don't for batteries.
| [deleted]
| tonymet wrote:
| the efficiency savings with this approach will outweigh any
| other effort
| WJW wrote:
| I don't think that's true. There are plenty of low-power
| setups that consume less than 2 watts, for an instant gain of
| 6/7ths or 85%. DC-to-AC-to-DC conversion is less than ideal,
| but even at a low estimate of only 90% efficiency at each
| step, that'd still be only a 1.0-(0.9^3)= ~28% loss.
| jakogut wrote:
| > With an idle load, this particular laptop draws 14W of power
| with the screen turned off.
|
| That's an extremely high idle power usage, I also have a laptop
| with a Ryzen 9 4900HS (the ROG Zephyrus G14, the only laptop with
| this chip, to my knowledge), and it idles around 9-11W with the
| screen _on_. Most of that is actually because of the RTX 2060
| that 's bundled with it, and won't turn off in Linux because
| Nvidia doesn't give a shit. I also suspect the author doesn't
| have a lot of power saving tunables enabled.
|
| By comparison, another laptop I have with a 4700U (also eight
| cores) and no discrete GPU idles at 2-3W.
|
| EDIT: If this author is reading this, this [0] is a good page to
| start from, along with powertop. I'd install and enable TLP,
| disable boost for efficiency, enable the tunables suggested by
| powertop, and maybe try nouveau for putting the GPU in the lowest
| power state.
|
| [0] https://wiki.archlinux.org/title/Power_management
| aero-glide2 wrote:
| You can use nvidia-prime to run on intel only right?
| Ballas wrote:
| > run on intel only
|
| How does that work on a Ryzen laptop?
| fragmede wrote:
| The English doesn't (quite work), but Intel here refers to
| the integrated, power-thrifty GPU, so could be more
| pedantically stated as "run on integrated graphics chip and
| turn off the Nvidia discrete GPU (and save power)" instead.
| [deleted]
| jtbayly wrote:
| I think you may have missed the point. It's Ryzen,
| meaning AMD, not Intel.
| sdfhhdfs wrote:
| Check out https://gitlab.com/asus-linux/asusctl. It provides a
| cli mechanism for switching between igpu-only, dgpu-only, and
| hybrid (nvidia card sleeps unless called via prime). If you use
| version 3.x, everything is built into asusctl. With 4.x,
| they've extracted that functionality to supergfxd/supergfxctl
| (in the same project).
| jakogut wrote:
| I'm currently using hybrid with PRIME offload and runtime D3
| enabled, but no matter what, the runtime D3 status is
| indicated as "Not Supported".
| Tade0 wrote:
| I'm getting similar results with my G14 (4800HS) running
| Windows on battery power and silent mode, which is interesting,
| because I originally gave up trying to have it run Linux
| because the dGPU would just spin like mad.
| forkfork wrote:
| Author here, you are correct, not tuned.
|
| Will try your suggestions! Much appreciated.
| eminence32 wrote:
| Meanwhile my basement R710 idles at like 180W :)
|
| (Obviously these two things aren't similar enough to compare
| directly, but it's fun to see the general progress/trend of
| powerusage over time. Cray-1 needed what? 100KW?)
| jacob019 wrote:
| You won't get 200W from a 200W panel in direct sunlight, but it
| will still generate some watts at other times, so it should work
| out.
|
| "A 4.6b year old yellow dwarf as a light source" loved that
| dreamcompiler wrote:
| Did you mean " _except_ in direct sunlight "?
| jacob019 wrote:
| The nominal rating is a peak rating, in my experience the
| sustained output will be somewhat less, even in direct
| sunlight.
| lazide wrote:
| Nod, unless you are in a place on the planet with perfect
| insolation (which would still only happen a few weeks of
| the year), it will nearly always will be below nameplate
| rating. The nameplate rating/testing if ever done, is done
| in a test bed with artificial light and perfect angle.
|
| Edit: I remember I did once get an above nameplate actual
| power output from a panel once - using MPPT, at high
| altitude, at the maximum insolation time for the year (mid-
| California in the mountains, right around the summer
| solstice). It only lasted for 20 minutes though.
| ctdonath wrote:
| Between experience and math, my rule is: on average, buffered
| with a battery, you'll get 10 watts out of a 100 watt panel
| (i.e.: 10% efficiency, all common conditions considered).
| rexreed wrote:
| I thought that was factored in when he talked about 3 full-
| hours of 200W across the full day? The day in Australia is
| certainly longer than 3 hours, so I figured that accounted for
| panel inefficiencies, indirect sunlight, and other such things.
| But could be wrong. Not sure how the 3 hours was calculated,
| but I am sure some solar calculators will take your location,
| average annual sunlight, efficiency and spit out an "effective
| daily solar hours" value that can be multiplied by the
| indicated solar panel wattage.
| forkfork wrote:
| 3 hours comes from averaging the daily power generation my
| Victron MPPT reports. I'm using a 200 watt panel and it
| reports and average of 600Wh since I set it up a month ago.
| rexreed wrote:
| Even better than a calculator - it's your actual experience
| ;)
| plorg wrote:
| In power systems there is a number called the capacity factor
| that is used to relate the average actual output to the
| nameplate capacity over whatever time interval. In this article
| the author note that they are expecting 600Wh in a day, or
| about an average of 3h at nameplate capacity. That works out to
| a capacity factor of about 0.13, which sounds about right for a
| solar installation that wasn't purpose built in an area of high
| insolation.
| giantg2 wrote:
| What about router/modem power draw? Needs to be some sort of
| connection to the internet to truly function as a website. (Not
| being connected would mean it's a wan site or intranet site)
| forkfork wrote:
| Good point. There is: a HFC modem & 2x Google Wifi access
| points. Totals to about 15W of energy use - which only leaves
| enough energy budget for a Raspberry Pi.
| seanwilson wrote:
| Are smartphones a good option here in terms of energy use?
| amelius wrote:
| What if you ditch the OS and code the server on the bare metal?
| wizzwizz4 wrote:
| The OS is very rarely the bottleneck.
| amelius wrote:
| Until it becomes the bottleneck.
| rdevsrex wrote:
| I think the title is misleading because the load depends on,
| well, the workload. But it's a thought provoking idea.
| PragmaticPulp wrote:
| Obviously there is infinite room for optimization of this
| problem, but this was a fun blog post. I'm interested to see
| where the author goes with the series.
| lmilcin wrote:
| It is interesting concept for a blog post but ruined by very
| inefficient implementation.
|
| I would expect orders of magnitude more work done on ~20W.
|
| Also parsing a compressed 10MB JSON seems like an unusual
| request. It would maybe be more fun to put a Hello World or Pet
| Store and get some numbers that will be more relatable to a
| regular developer.
| mhink wrote:
| I mean, everyone's gotta start somewhere. I'll give the
| author props for coming up with an idea for an experiment,
| documenting it, and sharing their results. Not a whole lot of
| people do that out in the open, and it's great to see a bunch
| of responses with suggestions for further improvements. :)
| f00zz wrote:
| Years ago someone made a potato-powered web server. It was an
| 8-bit microcontroller with a custom TCP/IP stack, if I
| remember correctly.
| forkfork wrote:
| Intentionally inefficient. I've seen a number of my customers
| doing this pattern, working with ~10 meg JSON for the model
| layer.
|
| Inefficient but not unrealistic outside of FAANG.
| dylan604 wrote:
| You must have a very low level of expectations of your fellow
| HN reader if you think that anything above a Hello World
| tutorial is relatable to a regular developer.
| turtlebits wrote:
| The test is for a web server, so you're optimizing for
| throughput on limited power, a static site would seem to be
| the best test.
|
| If you want to test CPU load, the author should have tried
| Prime95 or some other similar test.
| lmilcin wrote:
| How frequently do you test a new web framework with "10MB
| compressed JSONs"?
|
| On the other hand you can find a lot of benchmarks that use
| basically Hello World just to test your request response or
| some rather small request/response sizes, because this is
| what most applications actually do. You can add a simple
| database query to it for more realistic load.
|
| So, yes, this is more relatable to me as a backend
| developer because I can compare results more easily.
| dylan604 wrote:
| I see the issue with your premise. I don't test web
| frameworks. I do real work <ducks>
|
| I very much routinely look at large data sets. They just
| happen to be wrapped up in a different container than
| ZIP. Typically, they are delivered in MOV, MP4, WAV, etc.
| I look at a 10MB file and try to remember the last time I
| counted that small.
| egberts1 wrote:
| But you do do a minimal HTTP-free baseline benchmark for
| better insight of your comparison purpose of all things
| above?, no?
| karkisuni wrote:
| Adding the obligatory "what if M1" comment.
|
| Anandtech tested power draw of an M1 Mac Mini and found 4.2W at
| idle, 26.5W for the average multithreaded workload. 1/3rd idle
| power and the same power draw while running multithreaded
| benchmarks compared to the laptop serving a single client. Would
| be interesting to compare.
|
| https://www.anandtech.com/show/16252/mac-mini-apple-m1-teste...
| sfblah wrote:
| For the load expected for pulling data from a simple redis
| cache, is an M1 actually the most efficient chip? Isn't the
| point of the M1 that it supports a bunch of complex workflows
| while remaining efficient? Aren't there even more power
| efficient chips out there that focus exclusively on simple
| integer operations, etc.?
| masklinn wrote:
| > For the load expected for pulling data from a simple redis
| cache, is an M1 actually the most efficient chip?
|
| I think that's a good question with no trivial answer, there
| are certainly boards which consume significantly less energy
| than that and can serve traffic (using nginx and static
| content you can serve quite a lot on a watt or two, per
| https://solar.lowtechmagazine.com/2020/01/how-sustainable-
| is...), however if you factor in the need for actual CPU...
| cogman10 wrote:
| Mobile phone SoCs would likely be the way to go for the
| best processing per watt.
|
| The problem really is one of "how much is enough" more than
| anything else. Assuming someone wanted to really optimize
| something like this, a specialty built ARM cpu with lots of
| cores at a low frequency would likely provide the most
| ability to act as web server with a small power budget.
|
| Such SoCs, AFAIK, don't really exist. You don't need a
| particularly fast CPU for web service stuff. You certainly
| don't need all the mobile extras (AI chips, GPUs, etc).
| What you need more than anything is core count.
| judge2020 wrote:
| Sure. "STM32L1 MCUs also feature the industry's lowest power
| consumption of 170 nA in low-power mode with SRAM retention.
| ". But I think we're looking for the 'most efficient' general
| purpose computer.
|
| https://www.st.com/en/microcontrollers-
| microprocessors/stm32...
| genewitch wrote:
| Intel also made the quark which is a 486 that runs on a
| button cell battery, the same type that we'd call a cmos
| battery.
| wereHamster wrote:
| I was recently traveling with a M1 MacBook, and had a 20W solar
| panel + a 24Ah power bank for charging. Worked like a treat for
| coding.
| toddh wrote:
| Can you elaborate a little more on your setup? That sounds
| interesting.
| wereHamster wrote:
| Basically this: https://voltaicsystems.com/arc20w-kit/.
| It's a bit on the expensive side, I'm sure you can find
| cheaper kits. I like that the battery has a USB-C port, so
| I can charge the MacBook directly. To be truly off-grid,
| you need something bigger though. 20W is ok for basic work,
| but if you're compiling or doing other heavy work you need
| more power. If it's a bit cloudy then the battery won't
| fully charge with that panel, I'd recommend at least
| 50-100W. But with that size you're also less mobile. I had
| a car so mobility wasn't that important for me. The only
| important thing for me is that I can take the gear onto an
| airplane when traveling.
|
| I need to investigate if USB-C car charger adapters can
| charge a MacBook. When traveling with a car and the sun
| doesn't shine, it would be a nice backup solution. I was
| basically living in a car + tent for four weeks, traveling
| and working.
| ja27 wrote:
| Nekteck sells a car charger with 45W USB-C PD. I've seen
| others claiming 65W.
|
| https://www.nytimes.com/wirecutter/reviews/best-usb-car-
| char...
| shepting wrote:
| I've purchased a 90W USB C car charger:
| https://www.amazon.com/Charger-Cigarette-Lighter-Adapter-
| Cha...
| ctdonath wrote:
| I do similar with gear from https://GoalZero.com, typically
| using a car-portable 100W panel + 100Wh battery with USB-C
| support when seriously traveling, and a briefcase-friendly
| 20W folding panel + same battery when mobile. Wait for
| specials at https://REI.com to get good prices.
| jay_kyburz wrote:
| I'm keeping an eye on this gear as well.
|
| https://www.bluettipower.com.au/collections/portable-
| power-s...
| lxe wrote:
| Technically, it should be "200 watts". The losses happen due to
| all the inversion and conversion (I think... right?)
| marcosdumay wrote:
| TLDR (although it's quite short), he got 21W.
|
| The largest factor is the day-cycle. He gets 3 hours equivalent
| of Sun light a day. I really expected Australia to be more
| sunny than that.
| hinkley wrote:
| Planting trees around your house creates a lot of passive
| cooling, which can save you a lot of power on making the
| interior comfortable.
|
| It also makes roof top solar a bit of a joke.
| forkfork wrote:
| Mostly clouds and rain bring this down to 600Wh/day. Washed
| the bird poo off the panel to get an extra 2 watts.
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