[karkisuni]

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...

[wereHamster]

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]

Can you elaborate a little more on your setup? That sounds interesting.

[wereHamster]

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]

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]

I've purchased a 90W USB C car charger: https://www.amazon.com/Charger-Cigarette-Lighter-Adapter-Cha...

[ctdonath]

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]

I'm keeping an eye on this gear as well.

https://www.bluettipower.com.au/collections/portable-power-s...

[sfblah]

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]

> 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]

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.

[usrusr]

If you wanted to go full data slapstick you'd set up an elaborate protocol on the ISM band between a cluster of Nordic nrf52 or similar where each SoC serves exactly one page from its flash memory. Want to update the about page? Flash it on a spare board, connect it to the battery and disconnect the old version.

It will have awful latency, likely suffer hard from the shared medium if ramped to nontrivial loads, but it will hardly use any power at all.

And it will drive people nuts who know even the tiniest bit about computers, but those who don't will understand it just fine: "I disconnected that new about page and plugged the old version back in"

[judge2020]

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]

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.