Comment by moffkalast

13 hours ago

Well on the other hand, at which point does it become wasteful to run something when it gets less and less power efficient compared to newer devices? According to OP's benchmarks, the Pi 1 burns 2W constant to do essentially zero work and running that on a more modern device that's already running would use almost no extra power.

Then again we use a kW or two to microwave things for minutes on a daily basis so who really gives a shit.

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moffkalast

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horsawlarway  13 hours ago

Yeah... 2W is just not that much energy.

Enough energy to run that thing for an entire year in under 1/2 a gallon of gasoline.

When you can pretty easily offset the entire yearly energy use by skipping a mow of your yard once, or even just driving slightly more conservatively for a few days... I'm not so worried about the power use.

In my region - it's about $3.50 in yearly power costs.

01HNNWZ0MV43FF  11 hours ago

I did unplug my GPU to save 30 watts, but... 2 watts is equivalent to driving a Prius Prime 0.155 miles per day on battery power. So there's that

  • 3eb7988a1663  11 hours ago

    That seems an impossible range.

    This site[0] claims a Prius Prime XSE gets 1.42 miles/kWh. Or (1.42 miles /1000Wh)*2 = 0.0028 miles. Which is ~14 feet, which is significantly more in line with my expectations (though still high)

    [0] https://www.motortrend.com/reviews/2024-toyota-prius-prime-x...

    • tzs  9 hours ago

      You are missing a factor of 24, which comes in because they said "0.155 miles per day on battery power".

      The easiest way to do the calculation would be, assuming a Prius Prime can do M mi/kWh on battery power, is to calculate 0.155 mi/day x 1/M kWh/mi x 1 day/24h = 0.0065 kW = 6.5/M W. That gives us W which can directly be compared with the 2 W he gave.

      Also, 1.42 mi/kWh seems way low for battery power operation. I'm pretty sure that is for mixed gas/electric operation, expressed in MPG-e (47.9) and mi/kWh for convenient comparison to pure EVs. (You can convert between MPG-e and mi/kWh used the conversion factor for 33.7 kWh/gal.

      It has a 13.6 kWh battery and a 39 mile all electric range, which suggests M = 2.9 mi/kWh. Plugging that into 6.5/M W gives 2.2 W.

      M is probably actually a little higher because the car probably doesn't let the battery actually use 100% of its capacity. Most sites I see seem to say 3.1-3.5 mi/kWh.

      On the other hand there are some losses when charging. On my EV during times I've the year when I do not need to use the heating or AC the car is reporting 4.1 or higher mi/kWh, but it is measuring what is coming out of the battery.

      When calculated based on what is coming out of my charger it works out to 3.9 mi/kWh. This is with level 2 charging (240 V, 48 A). Level 1 charging is not as efficient as level 2.

      If we go with 3.1-3.5 mi/kWh, and assume that is measured on the battery output side and that the loses during charging are about 8%, we get 2.9-3.2 mi/kWh on the "this is what I've getting billed for" side. If we use the average of that and plug into 6.5/M W we get 2.1 W.