6 ms·

But it will mess up the power flow. Misbehaving powesupplies destroy HDDs.

by quickben 9y ago

cptskippy 9y ago
So a magnet held 6 inches away from the PC did more damage than the one inside the HDD literally inside the PC?
- 2muchcoffeeman 9y ago
  Yeah, I hope people realise that everybody has these magnets IN their computer. You might have a NAS in which case you have several of these magnets much closer than 6 inches to the other drives and power supply and nothing happens. Magnets near your or even on the computer do nothing.
  - Scramblejams 9y ago
    Magnets induce a current when moved relative to a conductor. The magnets you mention aren’t moving.
    - harshreality 9y ago
      So what you're saying is that nobody can hot swap drives in a NAS without destroying neighboring drives? I don't buy that either.
      - quickben 9y ago
        No, what he is saying, is that moving magnetic field, induces current, and can mess up the cheap power supply and/or other components, which can then mess up the drives. In a server, the power supply is on the other end of the chasis. In a laptop, it's a lot closer to the internals. > I don't buy that either. Theory: https://en.wikipedia.org/wiki/Electromagnetic_induction https://en.wikipedia.org/wiki/Electromagnetic_induction The forward model: https://www.youtube.com/watch?v=UL_ryxub-RA https://www.youtube.com/watch?v=UL_ryxub-RA The reverse model: https://www.youtube.com/watch?v=J9b0J29OzAU https://www.youtube.com/watch?v=J9b0J29OzAU The big ones: https://en.wikipedia.org/wiki/List_of_conventional_hydroelectric_power_stations https://en.wikipedia.org/wiki/List_of_conventional_hydroelec... Note: the Three Gorges: 22 GW For comparison, nuclear power: https://www.nei.org/Knowledge-Center/Nuclear-Statistics/US-Nuclear-Power-Plants https://www.nei.org/Knowledge-Center/Nuclear-Statistics/US-N... Largest U.S. nuclear plant: Palo Verde (Arizona) produces around 4 GW. For home applications: http://www.ebay.com/bhp/hydro-electric http://www.ebay.com/bhp/hydro-electric
        ars 9y ago
        Do you understand what you are saying? A person, moving a magnet near a single wire - not even a coil - is going to induce utterly insignificant amounts of electricity. You'd need lab equipment to even detect it. It will do absolutely nothing whatsoever to computer electronics.
        quickben 9y ago
        Open a powesupply before your next reply.
        ars 9y ago
        What am I supposed to reply to? Instead, why don't you take a multimeter and see if you can measure any voltage (never mind current) by moving a magnet, by hand, near a single non-coiled wire.
        quickben 9y ago
        Well honestly, I wrote that because I wasn't sure what to reply. I'm taking in five comments about power supplies, tons of wrapped wire, and I get a reply about a single wire. Anyways, I apologise for being snappy.
        harshreality 9y ago
        Nobody is suggesting that electromagnetic theory is false. The question is whether there's really a danger from HDD magnets in motion relative to nearby electronics or HDD platters. - HDDs often live right next to each other (separation of roughly 1cm, front to back). - Power supplies and their induction coils are right next to the drives in some cases, including for instance consumer grade NAS boxes. - HDDs tend to have a coil of wire, too. If HDD magnets overwriting nearby HDD data was a thing, it would be happening all the time. If HDD magnets in motion in certain orientations were inducing damaging currents in nearby HDDs or in nearby power supplies which then damaged connected components, that would be happening less often but still all the time. Not all chassis designs have power supplies at the opposite end as the disks, and some applications like consumer NAS boxes have them in close proximity to each other.
    - sandworm101 9y ago
      >> moved relative to a conductor Yes. The magnet is stationary and the spinning drive plate is moving the data, the conductor, very rapidly relative to the magnet. (imho the real issue is the large metal box surrounding the drive plates. It's hard to feel a magnet from inside a metal house.)
    - zaarn 9y ago
      When you swap drives, they are. Yet people don't have mysterious data loss when swapping drives out of their bays.
  - deleted 9y ago
    [deleted]
- deleted 9y ago
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But it will mess up the power flow. Misbehaving powesupplies destroy HDDs.

cptskippy 9y ago

So a magnet held 6 inches away from the PC did more damage than the one inside the HDD literally inside the PC?

2muchcoffeeman 9y ago
Yeah, I hope people realise that everybody has these magnets IN their computer. You might have a NAS in which case you have several of these magnets much closer than 6 inches to the other drives and power supply and nothing happens. Magnets near your or even on the computer do nothing.
- Scramblejams 9y ago
  Magnets induce a current when moved relative to a conductor. The magnets you mention aren’t moving.
  - harshreality 9y ago
    So what you're saying is that nobody can hot swap drives in a NAS without destroying neighboring drives? I don't buy that either.
    - quickben 9y ago
      No, what he is saying, is that moving magnetic field, induces current, and can mess up the cheap power supply and/or other components, which can then mess up the drives. In a server, the power supply is on the other end of the chasis. In a laptop, it's a lot closer to the internals. > I don't buy that either. Theory: https://en.wikipedia.org/wiki/Electromagnetic_induction https://en.wikipedia.org/wiki/Electromagnetic_induction The forward model: https://www.youtube.com/watch?v=UL_ryxub-RA https://www.youtube.com/watch?v=UL_ryxub-RA The reverse model: https://www.youtube.com/watch?v=J9b0J29OzAU https://www.youtube.com/watch?v=J9b0J29OzAU The big ones: https://en.wikipedia.org/wiki/List_of_conventional_hydroelectric_power_stations https://en.wikipedia.org/wiki/List_of_conventional_hydroelec... Note: the Three Gorges: 22 GW For comparison, nuclear power: https://www.nei.org/Knowledge-Center/Nuclear-Statistics/US-Nuclear-Power-Plants https://www.nei.org/Knowledge-Center/Nuclear-Statistics/US-N... Largest U.S. nuclear plant: Palo Verde (Arizona) produces around 4 GW. For home applications: http://www.ebay.com/bhp/hydro-electric http://www.ebay.com/bhp/hydro-electric
      - ars 9y ago
        Do you understand what you are saying? A person, moving a magnet near a single wire - not even a coil - is going to induce utterly insignificant amounts of electricity. You'd need lab equipment to even detect it. It will do absolutely nothing whatsoever to computer electronics.
        quickben 9y ago
        Open a powesupply before your next reply.
        ars 9y ago
        What am I supposed to reply to? Instead, why don't you take a multimeter and see if you can measure any voltage (never mind current) by moving a magnet, by hand, near a single non-coiled wire.
        quickben 9y ago
        Well honestly, I wrote that because I wasn't sure what to reply. I'm taking in five comments about power supplies, tons of wrapped wire, and I get a reply about a single wire. Anyways, I apologise for being snappy.
      - harshreality 9y ago
        Nobody is suggesting that electromagnetic theory is false. The question is whether there's really a danger from HDD magnets in motion relative to nearby electronics or HDD platters. - HDDs often live right next to each other (separation of roughly 1cm, front to back). - Power supplies and their induction coils are right next to the drives in some cases, including for instance consumer grade NAS boxes. - HDDs tend to have a coil of wire, too. If HDD magnets overwriting nearby HDD data was a thing, it would be happening all the time. If HDD magnets in motion in certain orientations were inducing damaging currents in nearby HDDs or in nearby power supplies which then damaged connected components, that would be happening less often but still all the time. Not all chassis designs have power supplies at the opposite end as the disks, and some applications like consumer NAS boxes have them in close proximity to each other.
  - sandworm101 9y ago
    >> moved relative to a conductor Yes. The magnet is stationary and the spinning drive plate is moving the data, the conductor, very rapidly relative to the magnet. (imho the real issue is the large metal box surrounding the drive plates. It's hard to feel a magnet from inside a metal house.)
  - zaarn 9y ago
    When you swap drives, they are. Yet people don't have mysterious data loss when swapping drives out of their bays.
- deleted 9y ago
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deleted 9y ago
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