Mixing
Is it safe to use a micro-USB 2 cable in a USB 3 portable hard drive?
The micro-B USB 3 port seems to be somewhat backwards compatible with the old micro-USB 2 standard. I was able to charge a phone that had the micro-B USB 3 port with a micro-USB 2 cable.
However, I am not sure to what extent this is a part of the USB standard or just something the phone manufacturer did for backwards compatibility.
I have a hard drive that uses micro-B USB 3. Would it be safe to use the USB 2 standard cable to read/power the hard drive?
ie. Use this cable for this port.
usb cable usb-storage usb-3 usb-2
asked Nov 20 '18 at 7:20
juil
269311
add a comment |
The micro-B USB 3 port seems to be somewhat backwards compatible with the old micro-USB 2 standard. I was able to charge a phone that had the micro-B USB 3 port with a micro-USB 2 cable.
However, I am not sure to what extent this is a part of the USB standard or just something the phone manufacturer did for backwards compatibility.
I have a hard drive that uses micro-B USB 3. Would it be safe to use the USB 2 standard cable to read/power the hard drive?
ie. Use this cable for this port.
usb cable usb-storage usb-3 usb-2
asked Nov 20 '18 at 7:20
juil
269311
3
@RicardoS. See grawity's answer, the extra connectors bring extra transmission lines. So it will work, albeit at USB 2.0 speeds. pinoutguide.com/PortableDevices/…
– Daniel F
Nov 20 '18 at 8:58
add a comment |
The micro-B USB 3 port seems to be somewhat backwards compatible with the old micro-USB 2 standard. I was able to charge a phone that had the micro-B USB 3 port with a micro-USB 2 cable.
However, I am not sure to what extent this is a part of the USB standard or just something the phone manufacturer did for backwards compatibility.
I have a hard drive that uses micro-B USB 3. Would it be safe to use the USB 2 standard cable to read/power the hard drive?
ie. Use this cable for this port.
usb cable usb-storage usb-3 usb-2
asked Nov 20 '18 at 7:20
juil
269311
The micro-B USB 3 port seems to be somewhat backwards compatible with the old micro-USB 2 standard. I was able to charge a phone that had the micro-B USB 3 port with a micro-USB 2 cable.
However, I am not sure to what extent this is a part of the USB standard or just something the phone manufacturer did for backwards compatibility.
I have a hard drive that uses micro-B USB 3. Would it be safe to use the USB 2 standard cable to read/power the hard drive?
ie. Use this cable for this port.
usb cable usb-storage usb-3 usb-2
usb cable usb-storage usb-3 usb-2
asked Nov 20 '18 at 7:20
juil
269311
asked Nov 20 '18 at 7:20
juil
269311
asked Nov 20 '18 at 7:20
juil
269311
asked Nov 20 '18 at 7:20
juil
269311
asked Nov 20 '18 at 7:20
juil
269311
269311
3
@RicardoS. See grawity's answer, the extra connectors bring extra transmission lines. So it will work, albeit at USB 2.0 speeds. pinoutguide.com/PortableDevices/…
– Daniel F
Nov 20 '18 at 8:58
add a comment |
3
@RicardoS. See grawity's answer, the extra connectors bring extra transmission lines. So it will work, albeit at USB 2.0 speeds. pinoutguide.com/PortableDevices/…
– Daniel F
Nov 20 '18 at 8:58
3
3
@RicardoS. See grawity's answer, the extra connectors bring extra transmission lines. So it will work, albeit at USB 2.0 speeds. pinoutguide.com/PortableDevices/…
– Daniel F
Nov 20 '18 at 8:58
@RicardoS. See grawity's answer, the extra connectors bring extra transmission lines. So it will work, albeit at USB 2.0 speeds. pinoutguide.com/PortableDevices/…
– Daniel F
Nov 20 '18 at 8:58
add a comment |
3 Answers
3
active
oldest
votes
Yes, it's safe. The base connector is identical to the original Micro-B, only adding the USB 3.0 data send/receive lines on the side. (USB 3.0 is backwards-compatible with 2.0, and this applies equally to all connectors it introduced – both the full-size and micro-size, type-A and type-B ports).
The end result will generally be the same as if connecting the drive to a computer's USB 2.0 port (which doesn't have these extra pins, either) – you'll be limited to the speed and power that USB 2.0 allows and won't be able to use UAS, but it should still work properly otherwise.
The extra pins are differential signal pairs (RX+, RX-, TX+, TX-, ground). Compare pinouts for:
- USB 2.0 Type-A/B and 3.0 Type-A/B
- USB 2.0 Micro-A/B and 3.0 Micro-A/B
- The official cable & connector specification is available from USB-IF for free.
Be sure to use a decent cable though, as magnetic disks will probably need the full 500 mA that a USB 2.0 port normally provides. Original phone cables should work fine (modern phones draw several times more anyway), but some cheap replacement cables might be unable to power the HDD at all, or it might repeatedly shut down while in use.
answered Nov 20 '18 at 8:12
grawity
232k35491546
2
adding to that, the USB 3.0 port is specified to provide at least 0.9A current (4.5W power), but no guarantee it's still available with USB 2.0 cable.
– iBug
Nov 20 '18 at 8:52
4
@iBug: Yes, but the devices already have to expect to be plugged into a computer's 2.0-only port, which as far as I know won't provide more than 0.5A regardless of cable – which is enough at least for the 2.5" HDDs that I've seen.
– grawity
Nov 20 '18 at 9:10
please note that depending on the USB2.0 Port you might not even get the specced 500mA at one port without issues like disconnecting devices or instable usage.
– Dennis Nolte
Nov 21 '18 at 9:54
Okay, so data speeds will obviously be impacted, and it's just a matter of making sure that enough power can be drawn through the cable?
– juil
Nov 24 '18 at 2:31
add a comment |
Yes, and no, with a small caveat.
Generally, this will work, and is perfectly safe (albeit considerably slower than using an USB 3 cable).
However, note that some disks require use too much power for USB 2.0 to be sufficient. While the amount of power that you can draw from USB 3 is quite amazing, USB 2.0 is kinda puny in that respect. There are disks which aren't happy with that.
This is still "safe" operation insofar as there is no way you could damage the disk (or the computer) by doing so, but it is not safe insofar as writing data might not be 100% reliable. Actually, it should either work or not work (in particular because spinning up successfully takes the most power), but you cannot be 100% sure. Writing does use more power than idling, and you never know for certain what goes on when a device is slightly under-powered. Generally, though, no worries. Usually it just does work or doesn't, so you can easily tell (all or nothing!), and most modern disks will be in the "just works" camp.
A workaround that is sometimes applied is using a Y-cable which sucks power from two USB 2.0 ports (but only uses one to transmit data). This is strictly a violation of the standard, but it "works fine".
Of course, this is only an applicable solution if you already happen to have one of these lying around (and maybe don't know what they're good for?) because a Y-cable is more expensive to buy than a proper USB 3 cable which will work within the specification and at USB 3 speed...
answered Nov 20 '18 at 10:13
Damon
3,53531624
I thought that USB power negotiation worked such that if the requested current isn't available, then that particular configuration isn't activated - i.e. a device that can't work on USB 2 power levels just won't operate, because the host won't find a configuration it can support.
– Toby Speight
Nov 20 '18 at 11:11
4
In theory, all devices must start at "one unit load" which is 150mA for USB3 and 100mA for USB2 (the USB3 device can detect absence of cables), and can then demand 5x as much. In practice, you get all kinds of funny stuff on every end (including host, adapter, and disks). I have an old 840evo which is officially rated "2.2W" (so at 5V well below 500mA) and has 0.86A @ 5V written on its back (WTF?) connected to my good old Wii U. The disk demonstrably pulls 0.1A idle and below 0.45A when writing, but without Y-cable the LED on the USB-SATA connector will go on, yet nothing else happens.
– Damon
Nov 20 '18 at 12:47
USB just sucks... unluckily there's nothing better :D
– Damon
Nov 20 '18 at 12:47
Spinning disks will draw much more power when spinning up, so even a disk which is content with 100mA in idle and ~450mA when being accessed will simply refuse to work when it doesn't get sufficient current to "take off" (start to spin). Apparently, no one ever thought about adding a small rechargeable battery to an enclosure, just to provide the extra bit of start-up current. Recharging would happen when the disk is spinning and the head is idle, possibly in less than a minute.
– Klaws
Nov 22 '18 at 9:09
add a comment |
Yes I can verify this works as I have tested this myself.
I have done this exact same thing with a WD Elements 2TB USB3 portable hard drive and multiple decent quality USB2 micro B cables without problems. But indeed it will be at USB2 speeds.
answered Nov 20 '18 at 12:37
Matthias Duyck
411
add a comment |
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "3"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsuperuser.com%2fquestions%2f1376877%2fis-it-safe-to-use-a-micro-usb-2-cable-in-a-usb-3-portable-hard-drive%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
Yes, it's safe. The base connector is identical to the original Micro-B, only adding the USB 3.0 data send/receive lines on the side. (USB 3.0 is backwards-compatible with 2.0, and this applies equally to all connectors it introduced – both the full-size and micro-size, type-A and type-B ports).
The end result will generally be the same as if connecting the drive to a computer's USB 2.0 port (which doesn't have these extra pins, either) – you'll be limited to the speed and power that USB 2.0 allows and won't be able to use UAS, but it should still work properly otherwise.
The extra pins are differential signal pairs (RX+, RX-, TX+, TX-, ground). Compare pinouts for:
- USB 2.0 Type-A/B and 3.0 Type-A/B
- USB 2.0 Micro-A/B and 3.0 Micro-A/B
- The official cable & connector specification is available from USB-IF for free.
Be sure to use a decent cable though, as magnetic disks will probably need the full 500 mA that a USB 2.0 port normally provides. Original phone cables should work fine (modern phones draw several times more anyway), but some cheap replacement cables might be unable to power the HDD at all, or it might repeatedly shut down while in use.
answered Nov 20 '18 at 8:12
grawity
232k35491546
2
adding to that, the USB 3.0 port is specified to provide at least 0.9A current (4.5W power), but no guarantee it's still available with USB 2.0 cable.
– iBug
Nov 20 '18 at 8:52
4
@iBug: Yes, but the devices already have to expect to be plugged into a computer's 2.0-only port, which as far as I know won't provide more than 0.5A regardless of cable – which is enough at least for the 2.5" HDDs that I've seen.
– grawity
Nov 20 '18 at 9:10
please note that depending on the USB2.0 Port you might not even get the specced 500mA at one port without issues like disconnecting devices or instable usage.
– Dennis Nolte
Nov 21 '18 at 9:54
Okay, so data speeds will obviously be impacted, and it's just a matter of making sure that enough power can be drawn through the cable?
– juil
Nov 24 '18 at 2:31
add a comment |
Yes, it's safe. The base connector is identical to the original Micro-B, only adding the USB 3.0 data send/receive lines on the side. (USB 3.0 is backwards-compatible with 2.0, and this applies equally to all connectors it introduced – both the full-size and micro-size, type-A and type-B ports).
The end result will generally be the same as if connecting the drive to a computer's USB 2.0 port (which doesn't have these extra pins, either) – you'll be limited to the speed and power that USB 2.0 allows and won't be able to use UAS, but it should still work properly otherwise.
The extra pins are differential signal pairs (RX+, RX-, TX+, TX-, ground). Compare pinouts for:
- USB 2.0 Type-A/B and 3.0 Type-A/B
- USB 2.0 Micro-A/B and 3.0 Micro-A/B
- The official cable & connector specification is available from USB-IF for free.
Be sure to use a decent cable though, as magnetic disks will probably need the full 500 mA that a USB 2.0 port normally provides. Original phone cables should work fine (modern phones draw several times more anyway), but some cheap replacement cables might be unable to power the HDD at all, or it might repeatedly shut down while in use.
answered Nov 20 '18 at 8:12
grawity
232k35491546
2
adding to that, the USB 3.0 port is specified to provide at least 0.9A current (4.5W power), but no guarantee it's still available with USB 2.0 cable.
– iBug
Nov 20 '18 at 8:52
4
@iBug: Yes, but the devices already have to expect to be plugged into a computer's 2.0-only port, which as far as I know won't provide more than 0.5A regardless of cable – which is enough at least for the 2.5" HDDs that I've seen.
– grawity
Nov 20 '18 at 9:10
please note that depending on the USB2.0 Port you might not even get the specced 500mA at one port without issues like disconnecting devices or instable usage.
– Dennis Nolte
Nov 21 '18 at 9:54
Okay, so data speeds will obviously be impacted, and it's just a matter of making sure that enough power can be drawn through the cable?
– juil
Nov 24 '18 at 2:31
add a comment |
Yes, it's safe. The base connector is identical to the original Micro-B, only adding the USB 3.0 data send/receive lines on the side. (USB 3.0 is backwards-compatible with 2.0, and this applies equally to all connectors it introduced – both the full-size and micro-size, type-A and type-B ports).
The end result will generally be the same as if connecting the drive to a computer's USB 2.0 port (which doesn't have these extra pins, either) – you'll be limited to the speed and power that USB 2.0 allows and won't be able to use UAS, but it should still work properly otherwise.
The extra pins are differential signal pairs (RX+, RX-, TX+, TX-, ground). Compare pinouts for:
- USB 2.0 Type-A/B and 3.0 Type-A/B
- USB 2.0 Micro-A/B and 3.0 Micro-A/B
- The official cable & connector specification is available from USB-IF for free.
Be sure to use a decent cable though, as magnetic disks will probably need the full 500 mA that a USB 2.0 port normally provides. Original phone cables should work fine (modern phones draw several times more anyway), but some cheap replacement cables might be unable to power the HDD at all, or it might repeatedly shut down while in use.
answered Nov 20 '18 at 8:12
grawity
232k35491546
Yes, it's safe. The base connector is identical to the original Micro-B, only adding the USB 3.0 data send/receive lines on the side. (USB 3.0 is backwards-compatible with 2.0, and this applies equally to all connectors it introduced – both the full-size and micro-size, type-A and type-B ports).
The end result will generally be the same as if connecting the drive to a computer's USB 2.0 port (which doesn't have these extra pins, either) – you'll be limited to the speed and power that USB 2.0 allows and won't be able to use UAS, but it should still work properly otherwise.
The extra pins are differential signal pairs (RX+, RX-, TX+, TX-, ground). Compare pinouts for:
- USB 2.0 Type-A/B and 3.0 Type-A/B
- USB 2.0 Micro-A/B and 3.0 Micro-A/B
- The official cable & connector specification is available from USB-IF for free.
Be sure to use a decent cable though, as magnetic disks will probably need the full 500 mA that a USB 2.0 port normally provides. Original phone cables should work fine (modern phones draw several times more anyway), but some cheap replacement cables might be unable to power the HDD at all, or it might repeatedly shut down while in use.
answered Nov 20 '18 at 8:12
grawity
232k35491546
edited Nov 20 '18 at 10:25
answered Nov 20 '18 at 8:12
grawity
232k35491546
answered Nov 20 '18 at 8:12
grawity
232k35491546
answered Nov 20 '18 at 8:12
grawity
232k35491546
232k35491546
2
adding to that, the USB 3.0 port is specified to provide at least 0.9A current (4.5W power), but no guarantee it's still available with USB 2.0 cable.
– iBug
Nov 20 '18 at 8:52
4
@iBug: Yes, but the devices already have to expect to be plugged into a computer's 2.0-only port, which as far as I know won't provide more than 0.5A regardless of cable – which is enough at least for the 2.5" HDDs that I've seen.
– grawity
Nov 20 '18 at 9:10
please note that depending on the USB2.0 Port you might not even get the specced 500mA at one port without issues like disconnecting devices or instable usage.
– Dennis Nolte
Nov 21 '18 at 9:54
Okay, so data speeds will obviously be impacted, and it's just a matter of making sure that enough power can be drawn through the cable?
– juil
Nov 24 '18 at 2:31
add a comment |
2
adding to that, the USB 3.0 port is specified to provide at least 0.9A current (4.5W power), but no guarantee it's still available with USB 2.0 cable.
– iBug
Nov 20 '18 at 8:52
4
@iBug: Yes, but the devices already have to expect to be plugged into a computer's 2.0-only port, which as far as I know won't provide more than 0.5A regardless of cable – which is enough at least for the 2.5" HDDs that I've seen.
– grawity
Nov 20 '18 at 9:10
please note that depending on the USB2.0 Port you might not even get the specced 500mA at one port without issues like disconnecting devices or instable usage.
– Dennis Nolte
Nov 21 '18 at 9:54
Okay, so data speeds will obviously be impacted, and it's just a matter of making sure that enough power can be drawn through the cable?
– juil
Nov 24 '18 at 2:31
2
2
adding to that, the USB 3.0 port is specified to provide at least 0.9A current (4.5W power), but no guarantee it's still available with USB 2.0 cable.
– iBug
Nov 20 '18 at 8:52
adding to that, the USB 3.0 port is specified to provide at least 0.9A current (4.5W power), but no guarantee it's still available with USB 2.0 cable.
– iBug
Nov 20 '18 at 8:52
4
4
@iBug: Yes, but the devices already have to expect to be plugged into a computer's 2.0-only port, which as far as I know won't provide more than 0.5A regardless of cable – which is enough at least for the 2.5" HDDs that I've seen.
– grawity
Nov 20 '18 at 9:10
@iBug: Yes, but the devices already have to expect to be plugged into a computer's 2.0-only port, which as far as I know won't provide more than 0.5A regardless of cable – which is enough at least for the 2.5" HDDs that I've seen.
– grawity
Nov 20 '18 at 9:10
please note that depending on the USB2.0 Port you might not even get the specced 500mA at one port without issues like disconnecting devices or instable usage.
– Dennis Nolte
Nov 21 '18 at 9:54
please note that depending on the USB2.0 Port you might not even get the specced 500mA at one port without issues like disconnecting devices or instable usage.
– Dennis Nolte
Nov 21 '18 at 9:54
Okay, so data speeds will obviously be impacted, and it's just a matter of making sure that enough power can be drawn through the cable?
– juil
Nov 24 '18 at 2:31
Okay, so data speeds will obviously be impacted, and it's just a matter of making sure that enough power can be drawn through the cable?
– juil
Nov 24 '18 at 2:31
add a comment |
Yes, and no, with a small caveat.
Generally, this will work, and is perfectly safe (albeit considerably slower than using an USB 3 cable).
However, note that some disks require use too much power for USB 2.0 to be sufficient. While the amount of power that you can draw from USB 3 is quite amazing, USB 2.0 is kinda puny in that respect. There are disks which aren't happy with that.
This is still "safe" operation insofar as there is no way you could damage the disk (or the computer) by doing so, but it is not safe insofar as writing data might not be 100% reliable. Actually, it should either work or not work (in particular because spinning up successfully takes the most power), but you cannot be 100% sure. Writing does use more power than idling, and you never know for certain what goes on when a device is slightly under-powered. Generally, though, no worries. Usually it just does work or doesn't, so you can easily tell (all or nothing!), and most modern disks will be in the "just works" camp.
A workaround that is sometimes applied is using a Y-cable which sucks power from two USB 2.0 ports (but only uses one to transmit data). This is strictly a violation of the standard, but it "works fine".
Of course, this is only an applicable solution if you already happen to have one of these lying around (and maybe don't know what they're good for?) because a Y-cable is more expensive to buy than a proper USB 3 cable which will work within the specification and at USB 3 speed...
answered Nov 20 '18 at 10:13
Damon
3,53531624
I thought that USB power negotiation worked such that if the requested current isn't available, then that particular configuration isn't activated - i.e. a device that can't work on USB 2 power levels just won't operate, because the host won't find a configuration it can support.
– Toby Speight
Nov 20 '18 at 11:11
4
In theory, all devices must start at "one unit load" which is 150mA for USB3 and 100mA for USB2 (the USB3 device can detect absence of cables), and can then demand 5x as much. In practice, you get all kinds of funny stuff on every end (including host, adapter, and disks). I have an old 840evo which is officially rated "2.2W" (so at 5V well below 500mA) and has 0.86A @ 5V written on its back (WTF?) connected to my good old Wii U. The disk demonstrably pulls 0.1A idle and below 0.45A when writing, but without Y-cable the LED on the USB-SATA connector will go on, yet nothing else happens.
– Damon
Nov 20 '18 at 12:47
USB just sucks... unluckily there's nothing better :D
– Damon
Nov 20 '18 at 12:47
Spinning disks will draw much more power when spinning up, so even a disk which is content with 100mA in idle and ~450mA when being accessed will simply refuse to work when it doesn't get sufficient current to "take off" (start to spin). Apparently, no one ever thought about adding a small rechargeable battery to an enclosure, just to provide the extra bit of start-up current. Recharging would happen when the disk is spinning and the head is idle, possibly in less than a minute.
– Klaws
Nov 22 '18 at 9:09
add a comment |
Yes, and no, with a small caveat.
Generally, this will work, and is perfectly safe (albeit considerably slower than using an USB 3 cable).
However, note that some disks require use too much power for USB 2.0 to be sufficient. While the amount of power that you can draw from USB 3 is quite amazing, USB 2.0 is kinda puny in that respect. There are disks which aren't happy with that.
This is still "safe" operation insofar as there is no way you could damage the disk (or the computer) by doing so, but it is not safe insofar as writing data might not be 100% reliable. Actually, it should either work or not work (in particular because spinning up successfully takes the most power), but you cannot be 100% sure. Writing does use more power than idling, and you never know for certain what goes on when a device is slightly under-powered. Generally, though, no worries. Usually it just does work or doesn't, so you can easily tell (all or nothing!), and most modern disks will be in the "just works" camp.
A workaround that is sometimes applied is using a Y-cable which sucks power from two USB 2.0 ports (but only uses one to transmit data). This is strictly a violation of the standard, but it "works fine".
Of course, this is only an applicable solution if you already happen to have one of these lying around (and maybe don't know what they're good for?) because a Y-cable is more expensive to buy than a proper USB 3 cable which will work within the specification and at USB 3 speed...
answered Nov 20 '18 at 10:13
Damon
3,53531624
I thought that USB power negotiation worked such that if the requested current isn't available, then that particular configuration isn't activated - i.e. a device that can't work on USB 2 power levels just won't operate, because the host won't find a configuration it can support.
– Toby Speight
Nov 20 '18 at 11:11
4
In theory, all devices must start at "one unit load" which is 150mA for USB3 and 100mA for USB2 (the USB3 device can detect absence of cables), and can then demand 5x as much. In practice, you get all kinds of funny stuff on every end (including host, adapter, and disks). I have an old 840evo which is officially rated "2.2W" (so at 5V well below 500mA) and has 0.86A @ 5V written on its back (WTF?) connected to my good old Wii U. The disk demonstrably pulls 0.1A idle and below 0.45A when writing, but without Y-cable the LED on the USB-SATA connector will go on, yet nothing else happens.
– Damon
Nov 20 '18 at 12:47
USB just sucks... unluckily there's nothing better :D
– Damon
Nov 20 '18 at 12:47
Spinning disks will draw much more power when spinning up, so even a disk which is content with 100mA in idle and ~450mA when being accessed will simply refuse to work when it doesn't get sufficient current to "take off" (start to spin). Apparently, no one ever thought about adding a small rechargeable battery to an enclosure, just to provide the extra bit of start-up current. Recharging would happen when the disk is spinning and the head is idle, possibly in less than a minute.
– Klaws
Nov 22 '18 at 9:09
add a comment |
Yes, and no, with a small caveat.
Generally, this will work, and is perfectly safe (albeit considerably slower than using an USB 3 cable).
However, note that some disks require use too much power for USB 2.0 to be sufficient. While the amount of power that you can draw from USB 3 is quite amazing, USB 2.0 is kinda puny in that respect. There are disks which aren't happy with that.
This is still "safe" operation insofar as there is no way you could damage the disk (or the computer) by doing so, but it is not safe insofar as writing data might not be 100% reliable. Actually, it should either work or not work (in particular because spinning up successfully takes the most power), but you cannot be 100% sure. Writing does use more power than idling, and you never know for certain what goes on when a device is slightly under-powered. Generally, though, no worries. Usually it just does work or doesn't, so you can easily tell (all or nothing!), and most modern disks will be in the "just works" camp.
A workaround that is sometimes applied is using a Y-cable which sucks power from two USB 2.0 ports (but only uses one to transmit data). This is strictly a violation of the standard, but it "works fine".
Of course, this is only an applicable solution if you already happen to have one of these lying around (and maybe don't know what they're good for?) because a Y-cable is more expensive to buy than a proper USB 3 cable which will work within the specification and at USB 3 speed...
answered Nov 20 '18 at 10:13
Damon
3,53531624
Yes, and no, with a small caveat.
Generally, this will work, and is perfectly safe (albeit considerably slower than using an USB 3 cable).
However, note that some disks require use too much power for USB 2.0 to be sufficient. While the amount of power that you can draw from USB 3 is quite amazing, USB 2.0 is kinda puny in that respect. There are disks which aren't happy with that.
This is still "safe" operation insofar as there is no way you could damage the disk (or the computer) by doing so, but it is not safe insofar as writing data might not be 100% reliable. Actually, it should either work or not work (in particular because spinning up successfully takes the most power), but you cannot be 100% sure. Writing does use more power than idling, and you never know for certain what goes on when a device is slightly under-powered. Generally, though, no worries. Usually it just does work or doesn't, so you can easily tell (all or nothing!), and most modern disks will be in the "just works" camp.
A workaround that is sometimes applied is using a Y-cable which sucks power from two USB 2.0 ports (but only uses one to transmit data). This is strictly a violation of the standard, but it "works fine".
Of course, this is only an applicable solution if you already happen to have one of these lying around (and maybe don't know what they're good for?) because a Y-cable is more expensive to buy than a proper USB 3 cable which will work within the specification and at USB 3 speed...
answered Nov 20 '18 at 10:13
Damon
3,53531624
answered Nov 20 '18 at 10:13
Damon
3,53531624
answered Nov 20 '18 at 10:13
Damon
3,53531624
answered Nov 20 '18 at 10:13
Damon
3,53531624
3,53531624
I thought that USB power negotiation worked such that if the requested current isn't available, then that particular configuration isn't activated - i.e. a device that can't work on USB 2 power levels just won't operate, because the host won't find a configuration it can support.
– Toby Speight
Nov 20 '18 at 11:11
4
In theory, all devices must start at "one unit load" which is 150mA for USB3 and 100mA for USB2 (the USB3 device can detect absence of cables), and can then demand 5x as much. In practice, you get all kinds of funny stuff on every end (including host, adapter, and disks). I have an old 840evo which is officially rated "2.2W" (so at 5V well below 500mA) and has 0.86A @ 5V written on its back (WTF?) connected to my good old Wii U. The disk demonstrably pulls 0.1A idle and below 0.45A when writing, but without Y-cable the LED on the USB-SATA connector will go on, yet nothing else happens.
– Damon
Nov 20 '18 at 12:47
USB just sucks... unluckily there's nothing better :D
– Damon
Nov 20 '18 at 12:47
Spinning disks will draw much more power when spinning up, so even a disk which is content with 100mA in idle and ~450mA when being accessed will simply refuse to work when it doesn't get sufficient current to "take off" (start to spin). Apparently, no one ever thought about adding a small rechargeable battery to an enclosure, just to provide the extra bit of start-up current. Recharging would happen when the disk is spinning and the head is idle, possibly in less than a minute.
– Klaws
Nov 22 '18 at 9:09
add a comment |
I thought that USB power negotiation worked such that if the requested current isn't available, then that particular configuration isn't activated - i.e. a device that can't work on USB 2 power levels just won't operate, because the host won't find a configuration it can support.
– Toby Speight
Nov 20 '18 at 11:11
4
In theory, all devices must start at "one unit load" which is 150mA for USB3 and 100mA for USB2 (the USB3 device can detect absence of cables), and can then demand 5x as much. In practice, you get all kinds of funny stuff on every end (including host, adapter, and disks). I have an old 840evo which is officially rated "2.2W" (so at 5V well below 500mA) and has 0.86A @ 5V written on its back (WTF?) connected to my good old Wii U. The disk demonstrably pulls 0.1A idle and below 0.45A when writing, but without Y-cable the LED on the USB-SATA connector will go on, yet nothing else happens.
– Damon
Nov 20 '18 at 12:47
USB just sucks... unluckily there's nothing better :D
– Damon
Nov 20 '18 at 12:47
Spinning disks will draw much more power when spinning up, so even a disk which is content with 100mA in idle and ~450mA when being accessed will simply refuse to work when it doesn't get sufficient current to "take off" (start to spin). Apparently, no one ever thought about adding a small rechargeable battery to an enclosure, just to provide the extra bit of start-up current. Recharging would happen when the disk is spinning and the head is idle, possibly in less than a minute.
– Klaws
Nov 22 '18 at 9:09
I thought that USB power negotiation worked such that if the requested current isn't available, then that particular configuration isn't activated - i.e. a device that can't work on USB 2 power levels just won't operate, because the host won't find a configuration it can support.
– Toby Speight
Nov 20 '18 at 11:11
I thought that USB power negotiation worked such that if the requested current isn't available, then that particular configuration isn't activated - i.e. a device that can't work on USB 2 power levels just won't operate, because the host won't find a configuration it can support.
– Toby Speight
Nov 20 '18 at 11:11
4
4
In theory, all devices must start at "one unit load" which is 150mA for USB3 and 100mA for USB2 (the USB3 device can detect absence of cables), and can then demand 5x as much. In practice, you get all kinds of funny stuff on every end (including host, adapter, and disks). I have an old 840evo which is officially rated "2.2W" (so at 5V well below 500mA) and has 0.86A @ 5V written on its back (WTF?) connected to my good old Wii U. The disk demonstrably pulls 0.1A idle and below 0.45A when writing, but without Y-cable the LED on the USB-SATA connector will go on, yet nothing else happens.
– Damon
Nov 20 '18 at 12:47
In theory, all devices must start at "one unit load" which is 150mA for USB3 and 100mA for USB2 (the USB3 device can detect absence of cables), and can then demand 5x as much. In practice, you get all kinds of funny stuff on every end (including host, adapter, and disks). I have an old 840evo which is officially rated "2.2W" (so at 5V well below 500mA) and has 0.86A @ 5V written on its back (WTF?) connected to my good old Wii U. The disk demonstrably pulls 0.1A idle and below 0.45A when writing, but without Y-cable the LED on the USB-SATA connector will go on, yet nothing else happens.
– Damon
Nov 20 '18 at 12:47
USB just sucks... unluckily there's nothing better :D
– Damon
Nov 20 '18 at 12:47
USB just sucks... unluckily there's nothing better :D
– Damon
Nov 20 '18 at 12:47
Spinning disks will draw much more power when spinning up, so even a disk which is content with 100mA in idle and ~450mA when being accessed will simply refuse to work when it doesn't get sufficient current to "take off" (start to spin). Apparently, no one ever thought about adding a small rechargeable battery to an enclosure, just to provide the extra bit of start-up current. Recharging would happen when the disk is spinning and the head is idle, possibly in less than a minute.
– Klaws
Nov 22 '18 at 9:09
Spinning disks will draw much more power when spinning up, so even a disk which is content with 100mA in idle and ~450mA when being accessed will simply refuse to work when it doesn't get sufficient current to "take off" (start to spin). Apparently, no one ever thought about adding a small rechargeable battery to an enclosure, just to provide the extra bit of start-up current. Recharging would happen when the disk is spinning and the head is idle, possibly in less than a minute.
– Klaws
Nov 22 '18 at 9:09
add a comment |
Yes I can verify this works as I have tested this myself.
I have done this exact same thing with a WD Elements 2TB USB3 portable hard drive and multiple decent quality USB2 micro B cables without problems. But indeed it will be at USB2 speeds.
answered Nov 20 '18 at 12:37
Matthias Duyck
411
add a comment |
Yes I can verify this works as I have tested this myself.
I have done this exact same thing with a WD Elements 2TB USB3 portable hard drive and multiple decent quality USB2 micro B cables without problems. But indeed it will be at USB2 speeds.
answered Nov 20 '18 at 12:37
Matthias Duyck
411
add a comment |
Yes I can verify this works as I have tested this myself.
I have done this exact same thing with a WD Elements 2TB USB3 portable hard drive and multiple decent quality USB2 micro B cables without problems. But indeed it will be at USB2 speeds.
answered Nov 20 '18 at 12:37
Matthias Duyck
411
Yes I can verify this works as I have tested this myself.
I have done this exact same thing with a WD Elements 2TB USB3 portable hard drive and multiple decent quality USB2 micro B cables without problems. But indeed it will be at USB2 speeds.
answered Nov 20 '18 at 12:37
Matthias Duyck
411
answered Nov 20 '18 at 12:37
Matthias Duyck
411
answered Nov 20 '18 at 12:37
Matthias Duyck
411
answered Nov 20 '18 at 12:37
Matthias Duyck
411
411
add a comment |
add a comment |
Thanks for contributing an answer to Super User!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsuperuser.com%2fquestions%2f1376877%2fis-it-safe-to-use-a-micro-usb-2-cable-in-a-usb-3-portable-hard-drive%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
3
@RicardoS. See grawity's answer, the extra connectors bring extra transmission lines. So it will work, albeit at USB 2.0 speeds. pinoutguide.com/PortableDevices/…
– Daniel F
Nov 20 '18 at 8:58