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> Gets me thinking tho: Why stop at 5.25in drives? Let's go back to washing machine sized units or even bigger. Let's stack platters so dense and heavy that we

> Gets me thinking tho: Why stop at 5.25in drives? Let's go back to washing machine sized units or even bigger. Let's stack platters so dense and heavy that we can use the spindle as a flywheel UPS system too. Because modern 20TB hard drives already take like a full week to read from beginning to end (aka: time for a RAID6 rebuild), which is too long as it is. The problem with hard drives is that they need "more read heads per byte" than the current technology. You can solve this by making more hard drives (ex: RAIDing together smaller drives, say 4x5TBs), so you have more read/write heads going over your data faster. There's multi-actuator hard drives coming up (2 independent heads per drive), which will report themselves to the OS as basically 2-hard drives in one case. I think that's where the storage market needs to go. ------------ Tape is the king of density: having the most bytes of storage on the fewest number of read/write heads possible. But Hard Drives encroach upon that space, especially with like 20TBs on one read/write head. > Or how about making a truly gigantic tape spool? Perhaps kevlar threads impregnated with iron could serve as "tape" and we could spin kilometers of that onto a spool. There's no advantage to that. A stack of 300 LTO-tapes will practically use up the same amount of space as one-tape that's 300x longer. (Besides, LTO-8 tapes are 960 meters long, roughly 1km. The idea of pulling on a thing that's 300km long and hoping for it to not rip itself apart is... pretty crazy. There's definitely some physical constraints / practicality with regards to just material science: shear/stress kind of calculations) The "jukebox" concept... really a tape-libraries (robot that picks tapes out of storage compartments and shoves them into the drive) is the ultimate solution to density.

hakfoo 5y ago
I never understood why they didn't make a hard disc that operated its heads in parallel and distributed data accordingly. Still one assembly, but using all the resources it has. You'd have (for example) a four-platter, eight head drive, and instead of storing a given byte serially at cylinder 123, head 0, sector 5, bytes 0-7, you'd store it at cylinder 123, sector 5, byte 0, and light up heads 0-7 all at once. Now, this might have been hard with early logical drive designs that tracked the physical geometry and expected a more serial format, but that was long ago hidden beneath LBA translation. Maybe there's a power or crosstalk issue with activating 8 heads at once.
- rasz 5y ago
  because at those scales heads on the same arm move in relation to one another due to vibration, thermal expansion etc

hakfoo 5y ago

I never understood why they didn't make a hard disc that operated its heads in parallel and distributed data accordingly. Still one assembly, but using all the resources it has. You'd have (for example) a four-platter, eight head drive, and instead of storing a given byte serially at cylinder 123, head 0, sector 5, bytes 0-7, you'd store it at cylinder 123, sector 5, byte 0, and light up heads 0-7 all at once. Now, this might have been hard with early logical drive designs that tracked the physical geometry and expected a more serial format, but that was long ago hidden beneath LBA translation. Maybe there's a power or crosstalk issue with activating 8 heads at once.

rasz 5y ago
because at those scales heads on the same arm move in relation to one another due to vibration, thermal expansion etc