Do portable HDD manufacturers know the USB power specs?

vbimport

#1

Rated: 5V 1.0 A.
These guys from Samsung are too stupid or ignorant to read and understand the USB specs :doh:

Do not use without an USB hub with PSU unless you hate your computer.

Michael


#2

I think that USB3 give 900mA, and 4Volts, i’ll try to find more info about that.
The problem should arise if you connect it on a USB2 port. But you can use a split Y cable to give more mA and volts.


#3

[QUOTE=vroom;2573482]I think that USB3 give 900mA, and 4Volts, [/quote]4V is the minimum voltage (for low power USB 3.0 devices). Not enough for a HDD. 900 mA is correct, indeed.

i’ll try to find more info about that.
www.usb.org :slight_smile:

The problem should arise if you connect it on a USB2 port. But you can use a split Y cable to give more mA and volts.
No. This is absolutely not spec compliant and might even cause severe trouble.
http://en.wikipedia.org/wiki/Usb#Non-standard_devices

Any hardware that is not specs compliant must be considered unreliable. Do you really want to use unreliable hardware for your backups? I do not.

Michael


#4

900ma is the minimum requirement, but I haven’t seen a motherboard with USB3 that can’t supply 1.8A, some as much as 3A.
Spec or no spec, the real world is often different to the spec.


#5

Generally the power rating is peak, which is when the disk spins up. I highly doubt it draws 1A continuously.

This Samsung also draws less power than my other USB portable HDDs. For example, I have a Western Digital Passport 250GB, which will not power up on my PC’s front ports and certain media player USB ports, where as this Samsung HDD powers up on every port I have tried it on so far.

Usually if the port does not provide enough power, one of the following things will happen:

[ol]
[li]The drive does not spin up. E.g. the WD passport’s LED will flash dark/bright blue continuously to indicate that it’s not receiving enough power.
[/li][li]The USB’s protection kicks in and disables the port, then Windows displays “Power surge on hub port - A USB Device has exceeded the power limits of its hub port”. I use to have this issue with an old webcam which was difficult to find a USB host capable of powering it. I never seen this error with any hard disk, so this webcam must have drawn a serious amount of current.
[/li][/ol]

Finally, I have never seen or even heard of a USB host or PSU being damaged by a USB device drawing too much power.


#6

[QUOTE=Dee;2573510]900ma is the minimum requirement,[/quote]And unless stated otherwise (i.e. The documentation of your motherboard or computer states something like “USB port up to xx mA”), you can’t expect more than the minimum defined by the specs.

but I haven’t seen a motherboard with USB3 that can’t supply 1.8A, some as much as 3A.
If this is stated in the product documentation, then this is okay IMO.

Spec or no spec, the real world is often different to the spec.
If no component manufacturer would design their stuff spec compliant, you wouldn’t have a new, shiny Sandy Bridge system that works, but a collection of single parts that won’t fit together.

[QUOTE=Seán;2573515]Generally the power rating is peak, which is when the disk spins up. I highly doubt it draws 1A continuously.[/quote]Accepted as true.

This Samsung also draws less power than my other USB portable HDDs. For example, I have a Western Digital Passport 250GB, which will not power up on my PC’s front ports and certain media player USB ports,
Such a piece of junk has to be returned to vendor.

Usually if the port does not provide enough power, one of the following things will happen:
The drive does not spin up. E.g. the WD passport’s LED will flash dark/bright blue continuously to indicate that it’s not receiving enough power.
Or intermittent spin-up retries until you pull the plug. HDDs love that.

The USB’s protection kicks in and disables the port, then Windows displays “Power surge on hub port - A USB Device has exceeded the power limits of its hub port”.
This is solely based on software and needs proper power demand signalling by the device.
http://support.microsoft.com/kb/310591

A USB device has [B]requested [/B]more power than the hub can provide.(…)
Most external drives are cheating here and do not properly request its power demand.

I never seen this error with any hard disk, so this webcam must have drawn a serious amount of current.

Bus powered HDDs are cheating.

Finally, I have never seen or even heard of a USB host or PSU being damaged by a USB device drawing too much power.
Want the fried USB hub that’s lying in my drawer? Yes, it had its own power supply.

Michael


#7

I have split this thread from the review discussion as this discussion focuses on HDD manufacturers breaching the USB spec rather than the review itself.


#8

As i said before the only real problem that i can find on this product is that it doesnt have a split Y cable, so that you can use on USB port to provide more power.
Other than that i believe that everything should, and as you say Sean, is working fine.

BTW Sean, does this work on a the system that refused to power up the WD drive?


#9

[QUOTE=vroom;2573565]BTW Sean, does this work on a the system that refused to power up the WD drive?[/QUOTE]
It works on the my PC’s front USB ports which the WD passport refuses to power up with.

I have tried the Samsung HDD on a wide range of computers, media players and USB-equipped TVs at this stage while out visiting and so far it has powered up on every USB port I tried it with.

I’m sure if any manufacturer’s portable HDD started blowing USB ports due to excessive power consumption, we would see something like the following:

[ul]
[li]New PCs and motherboards coming with disclaimer stickers covering the USB ports stating that damaged caused by the use of USB HDDs/devices drawing power in excess of 500mA will not be covered by warranty.[/li][li]Various consumer complaints about damaged USB ports/PSUs caused by their new USB HDD.[/li][li]Negative user reviews posted on online store product’s HDDs about the consequences.[/li][li]News about lawsuits filed against HDD manufacturers over damaged equipment caused by their product.[/li][/ul]

Sure, there will be the odd once off case, which to me seems just as likely as a TV going on the blink when someone hooks up their new DVD player.


#10

[QUOTE=vroom;2573565]As i said before the only real problem that i can find on this product is that it doesnt have a split Y cable, so that you can use on USB port to provide more power. [/QUOTE] Much to my surprise, I have found that the quality (for lack of a better word) of the USB cable is far more important than whether it’s a Y-cable with an additional plug for power.

I have tested around 10 different USB cables with a few 2.5" harddrives on my office desktop pc, which is the most finicky pc I have used when it comes to supplied USB power, and most of the USB Y-cables I have bought separately do NOT supply enough power for my most power-hungry drives even when the extra power-only USB plug is connected. But with the same USB port and the same external drive, some other USB cables do supply enough power, regardless of whether the extra power-only USB plug is connected or not.

It’s very surprising to me that there should be such a difference in resistance or other electrical properties of these cables, but since I have confirmed it many times with several different USB cables, I have to accept it as fact, and that it’s not a question of a few cables being defective.

So if you have trouble powering your external harddrive with an USB cable, you might want to just try another cable.

For maximum compatibility, I have purchased some 250 GB 1.8" USB harddrives (Samsung S1 Mini) which are specified to draw no more than 0.5A from the USB port, and these work with everything I have tried so far.


#11

[QUOTE=vroom;2573565]As i said before the only real problem that i can find on this product is that it doesnt have a split Y cable, so that you can use on USB port to provide more power. [/quote]As already stated:
Y-cables are evil (even if they work sometimes).
A spec compliant USB host should only release 100 mA since there is no power request possible (no data lines, plus one device can sign up only once). And haveing two power sources with different output (i.e. resistance) connected together might cause effects you do not want.

[QUOTE=Seán;2573575]
I’m sure if any manufacturer’s portable HDD started blowing USB ports due to excessive power consumption, we would see something like the following:[/quote]You won’t see that since mainboard and controller card manufacturers do not install protection circuits that would simply shut down the ports in case of overloading.
If they would have done that, then there wouldn’t be any host powered USB HDD/ODD (apart from the 1.8" variety) on the market.
The manufacturers rely on that and are hoping the USB port does not fry at the time of plugging in. A component that is permanently overloaded is likely to fail sooner or later.

[li]New PCs and motherboards coming with disclaimer stickers covering the USB ports stating that damaged caused by the use of USB HDDs/devices drawing power in excess of 500mA will not be covered by warranty.[/li]Good idea to put the stickers :iagree:
Even today, your warranty is not honored if you kill your USB port due to overloading. Unfortunately, the customers do not realize, that their non-spec-compliant device were to blame.
Such devices can be easily identified: they lack the official USB logo. Like the Samsung HDD you just reviewed.

[li]Various consumer complaints about damaged USB ports/PSUs caused by their new USB HDD.
[/li]> [li]Negative user reviews posted on online store product’s HDDs about the consequences.[/li]As said, most users don’t realize the reason of the problem they have. They happily accept that they can’t use the convenient front ports instead of returning the faulty device. And if they do, their computer is blamed instead of the crappy device, which is accepted by the ininformed customer.

News about lawsuits filed against HDD manufacturers over damaged equipment caused by their product.

It is really hard to prove that a certain incompliant device has caused the damage. And because of the things mentioned above, people didn’t even think to have (insert HDD manufacturer) to pay the cost of repairing a defective motherboard.

Michael


#12

[QUOTE=Seán;2573575]

I’m sure if any manufacturer’s portable HDD started blowing USB ports due to excessive power consumption, we would see something like the following:

[ul]
[li]New PCs and motherboards coming with disclaimer stickers covering the USB ports stating that damaged caused by the use of USB HDDs/devices drawing power in excess of 500mA will not be covered by warranty.[/li][li]Various consumer complaints about damaged USB ports/PSUs caused by their new USB HDD.[/li][li]Negative user reviews posted on online store product’s HDDs about the consequences.[/li][/ul]
[/QUOTE]

People have been posting comments about this, and you were were quick to move them out of sight.

You did not even leave a mention of removing 5 comments, until I asked.