External enclosures

[testcy]

Do external enclosures (2.5" or 3.5") still receive power from the usb port even when they are turned off? Does this mean that the enclosures or the usb ports on the motherboard can malfunction at any time if the cable is always connected?

[Dr. Will0hlep]

3 minutes ago, testcy said:

Do external enclosures (2.5" or 3.5") still receive power from the usb port even when they are turned off?

This depends on the USB port.

 

Easy way to tell: can you charge your phone from it while the PC is turned off.

 

3 minutes ago, testcy said:

Does this mean that the enclosures or the usb ports on the motherboard can malfunction at any time if the cable is always connected?

If it isn't actually doing anything, it shouldn't fail. (afaik)

[TudorFinalBosz]

If it's turned off it means it cannot receive power. The circuit is interrupted. This also unmounts the drive from the OS.

So I don't see how the system could still send power to a drive that it's now invisible to the system.

[testcy]

8 minutes ago, Dr. Will0hlep said:

This depends on the USB port.

 

Easy way to tell: can you charge your phone from it while the PC is turned off.

I am not asking about the PC being turned off, but about the external enclosures being turned off. In other words, if when the PC is turned on and the external enclosures are turned off, they still receive power from the usb ports through the cable which is always connected.

[Dr. Will0hlep]

1 minute ago, testcy said:

I am not asking about the PC being turned off, but about the external enclosures being turned off. In other words, if when the PC is turned on and the external enclosures are turned off, they still receive power from the usb ports through the cable which is always connected.

If the enclosure is off, then the main circuits should be broken, so it will not be recieving power.

[manikyath]

32 minutes ago, TudorF said:

If it's turned off it means it cannot receive power. The circuit is interrupted. This also unmounts the drive from the OS.

So I don't see how the system could still send power to a drive that it's now invisible to the system.

31 minutes ago, Dr. Will0hlep said:

If the enclosure is off, then the main circuits should be broken, so it will not be recieving power.

any dual-power enclosure (that being one with USB and a 12 volt jack) i've ever had taken apart didnt interrupt the incoming 5 volt supply from the PC if the enclosure was turned off.

 

but on that note...

47 minutes ago, testcy said:

Does this mean that the enclosures or the usb ports on the motherboard can malfunction at any time if the cable is always connected?

describe malfuction? because in theory any time your mouse is plugged into the computer both the mouse and the port it is plugged into "can malfuction".

 

what's the failure mode you're worried about, and why are you worried about it?

[testcy]

6 minutes ago, manikyath said:

any dual-power enclosure (that being one with USB and a 12 volt jack) i've ever had taken apart didnt interrupt the incoming 5 volt supply from the PC if the enclosure was turned off.

 

but on that note...

describe malfuction? because in theory any time your mouse is plugged into the computer both the mouse and the port it is plugged into "can malfuction".

 

what's the failure mode you're worried about, and why are you worried about it?

I worry about an expensive 3.5" hard disk failing in a dual-power enclosure with both USB and a 12 volt jack, especially if the 5 volt supply from the PC is never interrupted, even when the enclosure is turned off.

[TudorFinalBosz]

14 minutes ago, manikyath said:

any dual-power enclosure (that being one with USB and a 12 volt jack) i've ever had taken apart didnt interrupt the incoming 5 volt supply from the PC if the enclosure was turned off

If there's no consumer, there's no power being drawn from the mobo. There's just a buffer of energy that just sits there in the cable. And the mobo can't send more current.

[manikyath]

2 minutes ago, testcy said:

I worry about an expensive 3.5" hard disk failing in a dual-power enclosure with both USB and a 12 volt jack, especially if the 5 volt supply from the PC is never interrupted, even when the enclosure is turned off.

good news, if it's an expensive 3.5" hard drive it's probably made to run 24/7, so it's not gonna magically fail from doing nothing like seagate barracuda 3TB drives have been for the past decade.

[TudorFinalBosz]

3 minutes ago, testcy said:

I worry about an expensive 3.5" hard disk failing in a dual-power enclosure with both USB and a 12 volt jack, especially if the 5 volt supply from the PC is never interrupted, even when the enclosure is turned off.

Tbh I think that's the point of power on/off buttons on enclosures. To safely disconnect them from the system, even if they remain plugged in.

So you could make them available immediately by just turning them on.

That's the whole point of having such a feature, the convenience of it.

[manikyath]

3 minutes ago, TudorF said:

If there's no consumer, there's no power being drawn from the mobo. There's just a buffer of energy that just sits there in the cable. And the power source can't send more current.

it is receiving power, it might not be consuming anything notable, but 5 volts is present and being fed to the electroncis in the enclosure.

[manikyath]

2 minutes ago, TudorF said:

Tbh I think that's the point of power on/off buttons on enclosures. To safely disconnect them from the system, even if they remain plugged in.

So you could make them available immediately by just turning them on.

That's the whole point of having such a feature, the convenience of it.

the point of the on/off button is to not having the disk spin, which is entirely on the 12 volt side. in fact.. some enclosures literally dont do anything but cut 12 volts to the disk, and the enclosure itself doesnt even know if it's turned on or not.

[TudorFinalBosz]

1 minute ago, manikyath said:

it is receiving power, it might not be consuming anything notable, but 5 volts is present and being fed to the electroncis in the enclosure.

But the power button disconnects the HDD so there can't be any way any power can reach a drive that is taken offline.

Otherwise what's the point of a power button...

[manikyath]

2 minutes ago, TudorF said:

But the power button disconnects the HDD so there can't be any way any power can reach a drive that is taken offline.

Otherwise what's the point of a power button...

12 volt rail <=> 5 volt rail.

 

or should i go grab some enclosures and 5 volt only disks to prove a point?

[TudorFinalBosz]

1 minute ago, manikyath said:

12 volt rail <=> 5 volt rail.

 

or should i go grab some enclosures and 5 volt only disks to prove a point?

How does that relate to what I said. No current can reach the HDD drive if it's turned off. So that 5v current cannot damage it.

The 12v from its own cable is also interrupted, since it's not needed to spin any drive.

I don't see any problem here.

[manikyath]

2 minutes ago, TudorF said:

How does that relate to what I said. No current can reach the HDD drive if it's turned off. So that 5v current cannot damage it.

The 12v from its own cable is also interrupted, since it's not needed to spin any drive.

I don't see any problem here.

the switch *only* interrupts 12 volts coming from the external power brick, i've never encountered an enclosure that interrupts the 5 volts coming from the computer. basicly if you put a disk in the enclosure that only needs 5 volts to work (like most SSD's) the power button will just do nothing.

[Kilrah]

Typically on externally-powered 3.5" enclosures (never seen 2.5" ones with a switch) while there is technically 5V from the USB present somewhere since it comes from the cable it's basically not used for anything significant. 

So nothing to worry about. Unless you get a lightning strike or something but then you have much bigger problems. 

[TudorFinalBosz]

11 minutes ago, manikyath said:

if you put a disk in the enclosure that only needs 5 volts to work (like most SSD's) the power button will just do nothing.

Interesting, does that mean an external SSD that is turned off can still be read? If the power button does nothing...

[manikyath]

3 minutes ago, TudorF said:

Interesting, does that mean an external SSD that is turned off can still be read? If the power button does nothing...

yes, because the SSD isnt turned off, because the 12 volt rail is not relevant to the disk.

 

basicly, the layout in most enclosures is as follows:

 

- USB port data => USB to sata converter => sata data connector to the disk.

- USB port power => feeds above mentioned converter, and is connected trough to the +5V on the sata power plug

- 12V from the power brick => switch => +12V on the SATA power plug

- all grounds are connected together because that's what ground is.

 

pretty much, the "turning the enclosure on and off" relies entirely on SATA drives being fairly smart about managing their own power, noticing 12 volts isnt there, and disconnecting from the system.

[TudorFinalBosz]

21 minutes ago, manikyath said:

yes, because the SSD isnt turned off, because the 12 volt rail is not relevant to the disk.

 

basicly, the layout in most enclosures is as follows:

 

- USB port data => USB to sata converter => sata data connector to the disk.

- USB port power => feeds above mentioned converter, and is connected trough to the +5V on the sata power plug

- 12V from the power brick => switch => +12V on the SATA power plug

- all grounds are connected together because that's what ground is.

 

pretty much, the "turning the enclosure on and off" relies entirely on SATA drives being fairly smart about managing their own power, noticing 12 volts isnt there, and disconnecting from the system.

What about non-SATA drives