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we are learning how a disk rotates in order to preserve memory on the physical computer hardware. in order for this disk to preserve memory, it has to rotate by following laws of physics as a circular sphere with sine and cosine waves on the coordinate system. these sine and cosine waves that vibrate independently and periodically, which means that the disk rotates 10,000 orbits per second. a drill rotates 2000 orbits per second. 10,000 orbits per second is fast enough to cut your hand off in less than 1 millisecond. we are learning that this disk has to rotate so fast in order to preserve the memory which was stored by the database system with sql.

on a subject called sql databases.

Comments
  • 8
    Disks aren't memory, that's RAM, disks are storage...
  • 3
    Hard drives are fucking magic
    That's some legit engineering right there.
  • 4
    @ThomasRedstone sorry i... no clue what he was explaining, im just trying to figure out why do i have to know this in order to learn sql...
  • 3
    Basic filesystem/block storage structures were a part of my intro databases course too, but not that much detail lol, just some math regarding cylinders and tracks and all that
  • 0
  • 2
    @SukMikeHok it's important when you get into upper-level database courses and you actually have to learn how to store data so it can be queried efficiently
  • 0
    Odd. At my school, hard drive stuff was in a seperate subject that was actually about computers and computer science. Databases is its own subject.
  • 3
    What hard drive rotates at 10,000rpm? 5,400 to 7,200 are the typical rpm i know of.

    btw. i call bullshit on cutting a hand in less than 1ms.

    seems your course sucks :-/
  • 3
    @SomeRandomDude WD VelociRaptor drives run at 10,000 rpm.

    Kinda pointless because SSDs, but yeah. Those drives are quite fast for hard drives.
  • 4
    @RememberMe Whoa, imagine what a SSD will do to a human hand
  • 1
    @SukMikeHok yeah, no worries, storage and memory being used incorrectly is just one of my pet hates :-)
  • 3
    @SomeRandomDude I believe SCSI go all the way to 15k rpm. I don't think they would get that kind of speed in air
  • 1
    @ThomasRedstone
    They use helium to decrease the drag. Ar least some companies do i have no idea if that one does.
    The casing has to be gas proof and that is hard and expensive.
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