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I have a transcend 1 TB external drive (usb 2); It has two usb cables but also works if i connect the thicker one. Do i need to connect both for it to work properly or prevent damage or something?
Sam
Posted 2012-12-27T17:39:10.553
Reputation: 435
4
It's safer using both, since Harddisk may consume more Power on spin up, as USB is designed for.
Fourthly, many consumers and computer users buy 2.5” hard disk drives as portable storage devices inside USB chassis. A lot of chassis like that have no additional power supply, while a single USB connector can provide maximum 500mA current. So, some hard drives requiring a lot of power may face serious stability problems or may not be recognized by the system at all.
More information provided here
bummi
Posted 2012-12-27T17:39:10.553
Reputation: 1 569
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From the wikipedia article.
Some devices, such as high-speed external disk drives, require more than 500 mA of current and therefore may have power issues if powered from just one USB 2.0 port: erratic function, failure to function, or overloading/damaging the port. Such devices may come with an external power source or a Y-shaped cable that has two USB connectors (one for power+data, the other for power only) to be plugged into a computer. With such a cable, a device can draw power from two USB ports simultaneously.
Dave M
Posted 2012-12-27T17:39:10.553
Reputation: 12 811
0
The required currents are rarely documented but should normally be written on the drive.
E.g. all Seagate drives up to 500GB I've seen indicate +5V .45A and work on a single USB port.
But 750GB and 1TB drives show .75A or .90A and don't.
The current is maximum at spinup.
So, I suppose that a frequent .55A is OK on a single USB port as long as the drive starts.
if you're unable to read the drive label, you can do
$ lsblk -do NAME,MODEL
NAME MODEL
sda ST9750420AS
and look for that drive on eBay to read the current in its label.
Unfortunately
$ lsusb -d 14cd:6116 -v
Bus 001 Device 127: ID 14cd:6116 Super Top M6116 SATA Bridge
Self Powered
MaxPower 2mA
obviously indicate only the case requirement.
Papou
Posted 2012-12-27T17:39:10.553
Reputation: 128
-1
Would it be possible to connect the extra power plug to a usb charger/adapter in case that you only have one usb port avaible?
Richard Menke
Posted 2012-12-27T17:39:10.553
Reputation: 1
Welcome to Super User. The site's Q&A format reserves answers for solutions to the question. This post is really a comment or new question rather than an answer. You can always comment on your own posts, and once you have sufficient reputation you will be able to comment on any post. Non-answers tend to attract downvotes and are subject to deletion. But to answer your question: 1) It's generally not a good idea. 2) The adapter could be plugged into the drive. 3) A pass-through Y cable could be used.
– fixer1234 – 2016-09-03T16:47:22.790
A 1 TB USB2 drive is likely to need both cables. If you are low on USB ports, though, you can get a Y cable that has a pass-through connector on the power-only leg. It allows you to plug a low-power device, like a mouse or keyboard, into the second USB port so you don't lose a port. – fixer1234 – 2016-09-03T16:41:49.350
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I think it all depends on the device. Some devices need additional power to operate, they're able to get that extra power by using multiple USB connections. You can refer to this wikipedia article for specifics on USB 1.0 vs. 2.0 & 3.0. http://en.wikipedia.org/wiki/Universal_Serial_Bus#Power
– slm – 2012-12-27T18:23:08.227