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Seriously — laptop disks in a server? It might sound strange, but laptop disks actually have a lot of advantages for an always-on home server: they use le

Seriously — laptop disks in a server? It might sound strange, but laptop disks actually have a lot of advantages for an always-on home server: they use less energy, run very quiet, and take up little space. Although you pay roughly double the price per gigabyte compared to 3.5" disks, you pay less for electricity, and thus save money in the long run. I seriously doubt the power savings over the lifespan of a hard drive (5-6 years) are greater than paying twice as much per gigabyte. After all, if they were, Backblaze themselves would be using 2.5" disks. In any event, the disks in a home storage server are going to be spending most of their time spun down, and drawing very little power.

weiran 15y ago
The other advantages he mentioned (reduced heat, vibration, and as a consequence noise) would outweigh the price difference for a "living room" storage server. I certainly wouldn't want multiple 3.5" HDDs in my living room...
- sdfjkl 15y ago
  The disks are quiet, but the cooling fans they often require are not (at least that's what I've learnt from having a Drobo with four 3.5" disks in my living room).
  - timlossen 15y ago
    thats why i use an ultra-silent 140mm fan ... running it at 5V (instead of 12V) makes it practically unhearable.
  - DanBC 15y ago
    Why do hard-drives, in a small home server, need cooling fans?
    - pdubs 15y ago
      They probably don't. http://labs.google.com/papers/disk_failures.pdf http://labs.google.com/papers/disk_failures.pdf
      - timlossen 15y ago
        yes, that is true, the disks will run fine without. airflow is mostly for any heat generated by the sheeva and port-multiplier boards .... just to be on the safe side.
timlossen 15y ago
well, it partly depends on the local electricity rate you are paying .... which is probably a little higher here in europe than in the states, i guess. haven't really calculated the amortization time yet, though.
- windsurfer 15y ago
  10 watts per year is 87.6 kW h... how much are you paying for your electricity?
  - loki99 15y ago
    88kwh cost about 22$ here in Vienna, AT.
    - windsurfer 15y ago
      So for a 200$ drive versus a 100$ drive using 4x as much power with both having an expected life time of 4 years, the 100$ drive is still cheaper.
jws 15y ago
You are correct. Innumeracy raises its ugly head again. Powering a 3.5" disk drive costs about $4/year. Remember the rule of thumb: Each watt that you run all year long costs you $1/year in electricity. (Also, Backblaze drives probably spend most of their time spun down and thus use nearly no electricity.) EOM Some data: Model WD20EARS[1] WD10TPVT Size 3.5" 2.5" Cap 2TB 1TB R/W 5W 2.5W Idle 3.4W 0.85W Standby 0.7W 0.25W Cost $83 $118 So, figure the drives are mostly idle, but spinning, you would be $4/year for the 3.5" and $1/year for the 2.5", but you might need twice as many of the 2.5" drives to get the storage if you really need 2TB, but if you don't, then it will be 10 years to recover the savings on electric, but that is your own fault for not figuring out how to spin down your drives, and not understanding opportunity cost, you can invest that $30 you saved and make $1.5/year forever, even after your drives detect the end of their warranty and fail in 3 years. [1] Don't buy this drive. Something went horribly wrong in WD QC land. 1/3 of these that I bought failed their S.M.A.R.T. conveyance tests right out of the box and more failed in the first few months. The reviews at NewEgg suggest this is not an isolated experience. But, they are the ones I'm saddled with and know their data. Mine live out their lives happily spun down but for a few minutes a day and are closely monitored and mirrored, so their admittedly high risk of failure is acceptable.
- morsch 15y ago
  For what it's worth, your figures for the power draw of the WD20EARs seem to be too low -- Storage Review% measures R/W 6.5W-7.1W, idle 6.3W (odd) -- while the 2.5in drive figures are about right, but maybe a bit on the high side. And your rule of thumb for energy prices doesn't work in Germany (and possibly other countries), where 1W of electricity for one year will go for about USD 2.50, if not more. % http://www.storagereview.com/western_digital_caviar_green_2tb_review_wd20ears http://www.storagereview.com/western_digital_caviar_green_2t...
  - jws 15y ago
    The numbers I used are from WD's spec sheet. The Storage Review discrepancy is too large to easily explain. Either something is wrong with that test, or WD has posted fictitious numbers. The $1/year/watt rule is for the United States with a $0.12/kwHr cost. Even in the US the cost varies wildly, but just getting people within one order a magnitude on their electricity reasoning is worthwhile. I had no idea German electric rates were so high, but it does help explain why large solar power projects are feasible there despite the less than exciting insolation.
morsch 15y ago
Just for fun, here are some power consumption figures (based on data from storagereview.com%): Idle power draw (3.5in drives): around 5W Load power draw (3.5in drives): around 6.5W Spinup power draw (3.5in drives): around 15W Idle power draw (Samsung 2.5in): 0.58W Load power draw (Samsung 2.5in): 2.53W Spinup power draw (Samsung 2.5in): 3.89W Of course spun-down (as opposed to idling but spinning) HDDs draw far less power. I found a 2008 report# which measured spun down power, and it ranges widely but 10 to 20% of idle seems to be about right. (Not sure if there's a 2.5in drive among those they tested; I only skimmed the report.) If you disregard the spun-down thing for a moment, you get about 4W savings all the time, ie. 20W for the full array. That's about 175 kWh over a year. Assuming 0.20 EUR/kWh (which seems fairly typical for Germany), that's 35 EUR you save, per year. I guess that number can serve as an upper bound for the savings you can expect, chances are it'll be much lower: not a full array, 50% or more time spent spun-down, your energy prices might be lower. % http://www.storagereview.com/samsung_spinpoint_m8_review http://www.storagereview.com/samsung_spinpoint_m8_review http://www.storagereview.com/western_digital_caviar_green_2tb_review_wd20ears http://www.storagereview.com/western_digital_caviar_green_2t... # http://www.cl.cam.ac.uk/~acr31/pubs/hylick-harddrive2.pdf http://www.cl.cam.ac.uk/~acr31/pubs/hylick-harddrive2.pdf
- polshaw 15y ago
  >you get about 4W savings all the time, ie. 20W for the full array. It would either be ~2W or ~7W. Relevant to bear in mind the TB 2.5inch drives have more platters than standard height 2.5" so will use more power. 5x2.5" Drives = 2.9W 1x4TB Drives = 5W 2x3TB Drives = 10W You think 'i need X TB', not 'i need X drives'.
jsvaughan 15y ago
Perhaps power saving is the point, not money saving?
polshaw 15y ago
Energy costs PER GB can actually be lower/much closer in a 3.5 inch HDD by going with the largest capacity drives.

weiran 15y ago

The other advantages he mentioned (reduced heat, vibration, and as a consequence noise) would outweigh the price difference for a "living room" storage server. I certainly wouldn't want multiple 3.5" HDDs in my living room...

sdfjkl 15y ago
The disks are quiet, but the cooling fans they often require are not (at least that's what I've learnt from having a Drobo with four 3.5" disks in my living room).
- timlossen 15y ago
  thats why i use an ultra-silent 140mm fan ... running it at 5V (instead of 12V) makes it practically unhearable.
- DanBC 15y ago
  Why do hard-drives, in a small home server, need cooling fans?
  - pdubs 15y ago
    They probably don't. http://labs.google.com/papers/disk_failures.pdf http://labs.google.com/papers/disk_failures.pdf
    - timlossen 15y ago
      yes, that is true, the disks will run fine without. airflow is mostly for any heat generated by the sheeva and port-multiplier boards .... just to be on the safe side.

timlossen 15y ago

well, it partly depends on the local electricity rate you are paying .... which is probably a little higher here in europe than in the states, i guess. haven't really calculated the amortization time yet, though.

windsurfer 15y ago
10 watts per year is 87.6 kW h... how much are you paying for your electricity?
- loki99 15y ago
  88kwh cost about 22$ here in Vienna, AT.
  - windsurfer 15y ago
    So for a 200$ drive versus a 100$ drive using 4x as much power with both having an expected life time of 4 years, the 100$ drive is still cheaper.

jws 15y ago

You are correct. Innumeracy raises its ugly head again. Powering a 3.5" disk drive costs about $4/year. Remember the rule of thumb: Each watt that you run all year long costs you $1/year in electricity. (Also, Backblaze drives probably spend most of their time spun down and thus use nearly no electricity.) EOM Some data: Model WD20EARS[1] WD10TPVT Size 3.5" 2.5" Cap 2TB 1TB R/W 5W 2.5W Idle 3.4W 0.85W Standby 0.7W 0.25W Cost $83 $118 So, figure the drives are mostly idle, but spinning, you would be $4/year for the 3.5" and $1/year for the 2.5", but you might need twice as many of the 2.5" drives to get the storage if you really need 2TB, but if you don't, then it will be 10 years to recover the savings on electric, but that is your own fault for not figuring out how to spin down your drives, and not understanding opportunity cost, you can invest that $30 you saved and make $1.5/year forever, even after your drives detect the end of their warranty and fail in 3 years. [1] Don't buy this drive. Something went horribly wrong in WD QC land. 1/3 of these that I bought failed their S.M.A.R.T. conveyance tests right out of the box and more failed in the first few months. The reviews at NewEgg suggest this is not an isolated experience. But, they are the ones I'm saddled with and know their data. Mine live out their lives happily spun down but for a few minutes a day and are closely monitored and mirrored, so their admittedly high risk of failure is acceptable.

morsch 15y ago
For what it's worth, your figures for the power draw of the WD20EARs seem to be too low -- Storage Review% measures R/W 6.5W-7.1W, idle 6.3W (odd) -- while the 2.5in drive figures are about right, but maybe a bit on the high side. And your rule of thumb for energy prices doesn't work in Germany (and possibly other countries), where 1W of electricity for one year will go for about USD 2.50, if not more. % http://www.storagereview.com/western_digital_caviar_green_2tb_review_wd20ears http://www.storagereview.com/western_digital_caviar_green_2t...
- jws 15y ago
  The numbers I used are from WD's spec sheet. The Storage Review discrepancy is too large to easily explain. Either something is wrong with that test, or WD has posted fictitious numbers. The $1/year/watt rule is for the United States with a $0.12/kwHr cost. Even in the US the cost varies wildly, but just getting people within one order a magnitude on their electricity reasoning is worthwhile. I had no idea German electric rates were so high, but it does help explain why large solar power projects are feasible there despite the less than exciting insolation.

morsch 15y ago

Just for fun, here are some power consumption figures (based on data from storagereview.com%): Idle power draw (3.5in drives): around 5W Load power draw (3.5in drives): around 6.5W Spinup power draw (3.5in drives): around 15W Idle power draw (Samsung 2.5in): 0.58W Load power draw (Samsung 2.5in): 2.53W Spinup power draw (Samsung 2.5in): 3.89W Of course spun-down (as opposed to idling but spinning) HDDs draw far less power. I found a 2008 report# which measured spun down power, and it ranges widely but 10 to 20% of idle seems to be about right. (Not sure if there's a 2.5in drive among those they tested; I only skimmed the report.) If you disregard the spun-down thing for a moment, you get about 4W savings all the time, ie. 20W for the full array. That's about 175 kWh over a year. Assuming 0.20 EUR/kWh (which seems fairly typical for Germany), that's 35 EUR you save, per year. I guess that number can serve as an upper bound for the savings you can expect, chances are it'll be much lower: not a full array, 50% or more time spent spun-down, your energy prices might be lower. % http://www.storagereview.com/samsung_spinpoint_m8_review http://www.storagereview.com/samsung_spinpoint_m8_review http://www.storagereview.com/western_digital_caviar_green_2tb_review_wd20ears http://www.storagereview.com/western_digital_caviar_green_2t... # http://www.cl.cam.ac.uk/~acr31/pubs/hylick-harddrive2.pdf http://www.cl.cam.ac.uk/~acr31/pubs/hylick-harddrive2.pdf

polshaw 15y ago
>you get about 4W savings all the time, ie. 20W for the full array. It would either be ~2W or ~7W. Relevant to bear in mind the TB 2.5inch drives have more platters than standard height 2.5" so will use more power. 5x2.5" Drives = 2.9W 1x4TB Drives = 5W 2x3TB Drives = 10W You think 'i need X TB', not 'i need X drives'.

jsvaughan 15y ago

Perhaps power saving is the point, not money saving?

polshaw 15y ago

Energy costs PER GB can actually be lower/much closer in a 3.5 inch HDD by going with the largest capacity drives.