pouët.net

Since we have all sorts of arbitrary restrictions for demoscene categories and competitions (most notably, size or hardware ones), I am curious to hear whether there would be some interest in energy limited productions.

For example: demos that can run with only 12V and 0.1A of power, demos that don't eat up more than 10Wh/1Wh/100mWh over their entire running length, demos that run off a human powered device...

I'm aware this would be quite more involved than just writing something on an existing architecture, but there have already been hardware experiments in the past too, so I am curious how much interest a thing like that could get.

Do you have thoughts to share?

That would give PooBrain a totally unfair advantage, with their bus full of experienced/trained cyclists

I feel the idea is more "funny" than "fun", and the actual technical execution might be even more finicky than normal, given how energy consumption is dependent on a lot more variables than framerate.

Well that certainly is true, but in size coding the final binary size too depends on a lot of variables.

And since I'm mentioning size coding, I think there is some irony in how 64k and 4k are super efficient in getting the most out of the binary bytes, but as soon as they launch, they become extremely wasteful as part of the compromise. Which is one of the reasons for me asking if there is some interest in that topic.

Also, there was something pretty cool about the fact that to start his demo craft, lft just plugged a mere 9V battery to his board. I think it would be really cool to see some group come forward and say "Look, our demo uses a watch battery and it has crazy effects, try to beat that!".

put the musician on a stationary bike. his cycling speed dictates the tune's speed. can he cycle so steadily the music doesn't run off-sync from the visuals?

i don't volunteer though

Kind of an interesting concep, but I can’t see it being more then a compo for mobile demos. With results biased in favour of whoever can afford the latest phones with the most energy efficient SoC.

No it doesn't, a 4096 byte exe is 4096 bytes regardless of computer.

That's just a different set of variables. You can control some of them, others less so. The fact that here some of them are the execution conditions only moves the problem. It's not much different than, say, deciding that a demo shall not fall under 60fps.


P.S.: on the topic of human powered things, a few years ago a team of students won a prize for making a human powered flying vehicle that managed to stay airborne and hovering for a minute.

Been there, done that

Also, put led strips on the bike wheels and use that as a POV display.


@Gargaj: 4096 bytes is not "regardless of the platform", for example. Some executable headers are smaller or more flexible than others, and usually these are considered part of the executable size, so you don't get exactly 4096 bytes to work with.


All of this sounds like perfect material for a wild entry, anyway. Do it, and if a lot of people end up following maybe you can consider a dedicated compo. That's how it works :)

first who develops potato-powered AI wins the cake

As arbitrary as demoscene limitations seem, I think they all exist for a reason. Be it a historical one or just because somebody exploited a certain limitation while creating an outstanding result.

I fail to see the particular need for this one. Yet. Maybe, if you made a production that makes clear the restriction vs trickyness vs outcome in an awesome way, you'll find followers.

Otherwise it's just too arbitrary.

For a off-the-grid demoparty (like Underground Conference, somewhat), this can be a fun compo though. Your demoplatform must run on 4 AA batteries and be placed outside on the meadow.

this is more hackerspace fun than demoscene fun, i guess

Yes, a wild entry would definitely be the place to start. But I was curious to see how the idea would bounce when thrown here.

Why, I'm glad you ask.

I can see three different reasons, stacked on top of each other, for energy consumption to become a major concern in computers.

Computers are becoming more and more tiny decentralized thingies, in which battery autonomy is becoming the limiting factor. Think smartphones, wearable computing, Internet of Sh..Things, un-tethered AR/VR headsets. How fast apps drain your phone's battery is already becoming a thing users pay attention to.

On the higher end, heat dissipation is one of the limiting factors that is causing headaches to processor designers. Apparently we're headed more and more toward modular, specialized CPUs that can light up on demand then turn dark again. There was a very interesting talk on the topic by Sophie Wilson (one of the designers of the first ARM).

And at a much larger scale, there seems to be also a good chance we are headed toward an energy crisis, due to the combination of passing/having passed the peak of oil production and the increasing pressure to produce low carbon energy, all while our energy needs keep increasing.

So if writing energy efficient code becomes a thing, I think it would make sense for the demoscene to show off on that front too.

@rutra80

I see what you did there.

Fun story from some computerphile youtube vid: when they were power-testing the original ARM chip, they forgot to connect the power wires, but the chip still worked; it just sucked enough power through the signal wires to function.

The whole power thing is actually kinda funny.

Back at Fathammer (a pre-iphone era mobile game engine company) we went through tons of phone models and PDAs where the engineers did their best to make the batteries last as long as possible, while we did our best to make the batteries drain as fast as possible to get any kind of usable framerate out of the devices...

I remember one particular device onto which I ported some tech demo of ours, then walked around the office to show people that hey, this one is actually pretty fast. By the time I had walked back, the battery was flat.

Anyway. From a purely software point of view, the best you can do is do basically nothing. Maybe leverage cheap hardware features (palette cycling comes to mind..). On hardware side there's more stuff you can do. As such, I don't know if this suits demoscene as such.. except for the whole "faking it" factor, maybe.

My 'yet' says hello to your 'if' ;)

I think what I was trying to say was: make a demo about it and you'll see if others follow.

I don't think we need more compos. Test the waters with an entry and see if it gains traction.



Let's stick to actual power consumption (watts/joules) and let people figure out their own voltage/current ratios, okay? ;)

...that’s probably enough to run a decent raymarcher at 1080p for an hour on a recent phone. Which is why I can’t see how this doesn’t just turn into a mobile demo compo :)

Since running (in outfits and all that shit) is a thing now, why not a hand cranked variant?

I think focus on power usage would be great, but I wonder if you could measure it in a sensible way.

Yeah, society yet has to find to a way to measure power consumption. Please tell me you're in your first year of high school at most? :)

A major factor for energy consumption is the display used: LCDs and eInk hardly use any, LEDs some more, backlit TFT even more and CRT or projectors literally burn it.

So is just the computing platform of relevance or the display as well?

You forgot about lasers and tesla coils.

... or just make a thing that does not use any electrical power at all. Steam-powered devices anyone?

it's not the Exact same thing. :) still nice