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Writing a terabyte of information at 10c/kwh would cost $3.78 [1]. Not nothing, but doesn't seem entirely impractical for all cases. Heat dissipation might be

by gpm 3y ago

Writing a terabyte of information at 10c/kwh would cost $3.78 [1]. Not nothing, but doesn't seem entirely impractical for all cases. Heat dissipation might be an issue? [1] https://www.wolframalpha.com/input?i=17+%CE%BCJ+%2F+bit+*+1+terabyte+in+kwh+*+10+cents%2Fkwh https://www.wolframalpha.com/input?i=17+%CE%BCJ+%2F+bit+*+1+...

camel_gopher 3y ago
Interesting. I think AWS Athena is $5/TB for queries.
camkego 3y ago
I tried some numbers for writing to hard drives (it seems like SSDs are hard drives are not super far-apart on energy per byte written) And it seems like writing to HDDs is between $.15 to $.56 per TB depending on write speed and watts/time assumptions. It gets tricky to think about because there the sunk cost of powering the drive when idle, and the delta between idle and write power needs, but I think that range is representative for $/TB on a HDD. Wolfram link: https://www.wolframalpha.com/input?i=20w+*+second%2F100MB+*+1TB+in+kwh+*+10c%2Fkwh https://www.wolframalpha.com/input?i=20w+*+second%2F100MB+*+...
- tgsovlerkhgsel 3y ago
  > writing to HDDs is between $.15 to $.56 per TB That seems obviously wrong (writing a TB will consume less than 1 kWh), and indeed your link shows 0.56 cents (i.e. $0.0056) per TB.
  - zoky 3y ago
    It is definitely wrong, there’s no way a hard drive that can write a TB in, say, 4 hours would consume anything close to 250 watts.
tgsovlerkhgsel 3y ago
37.8 kWh per TB, so about 10 kW at a write speed of ~75 MB/s (~3.7 hours for the TB). That means you'd not only have to deal with the heat dissipation of ~five space heaters at full power, but you'd also need three-phase power to supply it.
- mort96 3y ago
  Or write slower I guess?
  - liftm 3y ago
    At 75 MB/s, this thing takes 30 days to fill. How much slower would you like?
    - gpm 3y ago
      Who says we need to fill it up in a reasonable time frame? If each disk costs a comparable amount to a dvd (cents) then the expensive part is the electricity (and maybe the equipment to write to them) and it's ok if most of the theoretical storage capacity goes unused. The important metric here for something like data backup is cost/byte to write and cost/byte/month to maintain.
      - liftm 3y ago
        > Who says we need to fill it up in a reasonable time frame? So you yourself are saying anything longer than a month is unreasonable? In any case, this lab experiment will need much improvement in speed and energy requirements.
        gpm 3y ago
        No, I'm suggesting that it could take a decade and still given the numbers in the thread I replied to (which I agree appear not to reflect reality) be a viable product. It never needs to be 'full'.
    - 3y ago

by gpm 3y ago

camel_gopher 3y ago

Interesting. I think AWS Athena is $5/TB for queries.

camkego 3y ago

I tried some numbers for writing to hard drives (it seems like SSDs are hard drives are not super far-apart on energy per byte written) And it seems like writing to HDDs is between $.15 to $.56 per TB depending on write speed and watts/time assumptions. It gets tricky to think about because there the sunk cost of powering the drive when idle, and the delta between idle and write power needs, but I think that range is representative for $/TB on a HDD. Wolfram link: https://www.wolframalpha.com/input?i=20w+*+second%2F100MB+*+1TB+in+kwh+*+10c%2Fkwh https://www.wolframalpha.com/input?i=20w+*+second%2F100MB+*+...

tgsovlerkhgsel 3y ago
> writing to HDDs is between $.15 to $.56 per TB That seems obviously wrong (writing a TB will consume less than 1 kWh), and indeed your link shows 0.56 cents (i.e. $0.0056) per TB.
- zoky 3y ago
  It is definitely wrong, there’s no way a hard drive that can write a TB in, say, 4 hours would consume anything close to 250 watts.

tgsovlerkhgsel 3y ago

37.8 kWh per TB, so about 10 kW at a write speed of ~75 MB/s (~3.7 hours for the TB). That means you'd not only have to deal with the heat dissipation of ~five space heaters at full power, but you'd also need three-phase power to supply it.

mort96 3y ago
Or write slower I guess?
- liftm 3y ago
  At 75 MB/s, this thing takes 30 days to fill. How much slower would you like?
  - gpm 3y ago
    Who says we need to fill it up in a reasonable time frame? If each disk costs a comparable amount to a dvd (cents) then the expensive part is the electricity (and maybe the equipment to write to them) and it's ok if most of the theoretical storage capacity goes unused. The important metric here for something like data backup is cost/byte to write and cost/byte/month to maintain.
    - liftm 3y ago
      > Who says we need to fill it up in a reasonable time frame? So you yourself are saying anything longer than a month is unreasonable? In any case, this lab experiment will need much improvement in speed and energy requirements.
      - gpm 3y ago
        No, I'm suggesting that it could take a decade and still given the numbers in the thread I replied to (which I agree appear not to reflect reality) be a viable product. It never needs to be 'full'.
  - 3y ago