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With same density, it should be possible to pack a Petabyte into 3.5" drives. Wonder why Intel went with a new "Ruler" physical format for its Petabyte drive i

With same density, it should be possible to pack a Petabyte into 3.5" drives. Wonder why Intel went with a new "Ruler" physical format for its Petabyte drive instead of 3.5" format.

simcop2387 9y ago
Like everything silicon, I'd bet heat dissipation. As you make things more dense and thicker like that you end up needing more space just to get rid of the heat. Intel's ruler gives a better surface area to volume ratio to get rid of the heat. The 3.5" form factor (and even the 5.25") makes a lot more sense for rotating platters since those scale linearly with vertical space (or at least close to it) because they're not dissipating heat off the platters like you need to with ICs.
- wtallis 9y ago
  Yep, heat dissipation is one of the big factors. The other is that 2.5" SSDs mean you can only easily use the front 6" of your server for hot-swappable storage. The Intel Ruler/EDSFF Long form factors let you devote much more of the total server volume to storage that's still accessible from the front of the machine.
scrooched_moose 9y ago
Where are you getting that? A 3.5" drive has a volume of 18.56 in^3 and a 2.5" about 4.48 in^3 [1]. Applying that scaling you'd get 124 TB 1) http://smallbusiness.chron.com/difference-between-25-35-hard-drives-67453.html http://smallbusiness.chron.com/difference-between-25-35-hard...
- fuzzythinker 9y ago
  Yes, physical dimensions ratio is 18.56 / 4.48 = 4.14. This makes 3.5" drive max out at 124TB. However, a good portion of the space is "overhead" for enclosure, connectors and circuit board. This overhead won't need to be multiplied by 4.14. So we may not be able to fit 1 PB into 3.5", but it will be closer than just 124TB.
wmf 9y ago
36 rulers probably gives higher performance than 12 3.5" SSDs. Large-capacity SSDs also increase the "blast radius" of data lost in a failure.

With same density, it should be possible to pack a Petabyte into 3.5" drives. Wonder why Intel went with a new "Ruler" physical format for its Petabyte drive instead of 3.5" format.

simcop2387 9y ago

Like everything silicon, I'd bet heat dissipation. As you make things more dense and thicker like that you end up needing more space just to get rid of the heat. Intel's ruler gives a better surface area to volume ratio to get rid of the heat. The 3.5" form factor (and even the 5.25") makes a lot more sense for rotating platters since those scale linearly with vertical space (or at least close to it) because they're not dissipating heat off the platters like you need to with ICs.

wtallis 9y ago
Yep, heat dissipation is one of the big factors. The other is that 2.5" SSDs mean you can only easily use the front 6" of your server for hot-swappable storage. The Intel Ruler/EDSFF Long form factors let you devote much more of the total server volume to storage that's still accessible from the front of the machine.

scrooched_moose 9y ago

Where are you getting that? A 3.5" drive has a volume of 18.56 in^3 and a 2.5" about 4.48 in^3 [1]. Applying that scaling you'd get 124 TB 1) http://smallbusiness.chron.com/difference-between-25-35-hard-drives-67453.html http://smallbusiness.chron.com/difference-between-25-35-hard...

fuzzythinker 9y ago
Yes, physical dimensions ratio is 18.56 / 4.48 = 4.14. This makes 3.5" drive max out at 124TB. However, a good portion of the space is "overhead" for enclosure, connectors and circuit board. This overhead won't need to be multiplied by 4.14. So we may not be able to fit 1 PB into 3.5", but it will be closer than just 124TB.

wmf 9y ago

36 rulers probably gives higher performance than 12 3.5" SSDs. Large-capacity SSDs also increase the "blast radius" of data lost in a failure.