Question How much current can a USB 2.0 cable handle?

[knowledge2121]

let me explain the situation a bit:

I want to use my 2.5" HDDs and SSDs externally through he USB 2.0 ports on my Xbox 360 and PS3 consoles with the use of a USB 3.0 to SATAIII enclosure/adaper. The amount of current that 2.5" HDDs/SSDs need varies(Approximately 400mA to 1A ?) . A single USB 2.0 port on the consoles can only supply 500mA. I have two options to power the HDDs/SSDs properly:

Option one: Use a "powered" USB to SATA adapter/enclosure.(comes with a power adapter).

Option two: Use a Y-USB cable to power the USB to SATA adapter/enclosure.

Questions about "Option two":

- Does the Y-USB cable for the enclosure supply 1A(500mA+500mA) of current if I plug both USB plugs into two USB 2.0 ports?

- What happens if I connect one of the plugs(DATA) into a USB.20 port and plug the other one into a USB charger that can supply 1-2A?

- Should I worry that the USB cables are USB 2.0 or USB 3.0? both types can support the same amperage?

 

[rgd1101]

use #1

 

[dwd999]

another vote for option 1

 

[USAFRet]

#1

 

[evermorex76]

Unless needing to plug in one extra little brick would be a humongous pain (like it might be if you were using a portable drive and had to carry it in your bag), I can't see why you wouldn't just go with #1 so you'd be sure everything would work and could forget about it. There are plenty of drives listed online though that only have one connector and claim to work with Xbox 360.

But obviously the Y-cable that comes with an enclosure ought to be rated to carry the current needed by the enclosure, and it doesn't matter whether the ports you plug it into are capable of more than is needed. You can't plug something into a socket that provides too much or too little voltage or it will cause damage or fire or blow a fuse, but you can plug devices into a socket that is capable of tremendously more amperage than needed. The current rating on the port is what's AVAILABLE to the device, not what is constantly being pushed to the device. If your enclosure wants 1.2A in order to power itself and a drive, then it will only pull 1.2A at most even if you plugged it into a port that supplied 300A. It's the same as your household devices, which use 110/120V in the US and connect to sockets that are probably rated for 15A, and both your low-power alarm clock and your 1500W space heater will work. (Of course if the enclosure wanted 300A and you plugged it into a 500mA port it could blow the fuse/port or start a fire or just not work.)

So yes, you should be able to plug the first connector of the cable into the console (that one has the data pins) and the extra connector into a charger or some other device that supports higher current. I'm not sure how much current it would end up pulling from each side. I imagine it would still pull it evenly from both sides, meaning you'd still only have a total of 1A. The wires likely connect to each other so there's only one connection in the enclosure, so no way to control how much is drawn from one side or the other. This ought to be enough even for most 2.5 inch mechanical drives plus the enclosure, except the oldest ones or those thick and heavy models that have many platters, which take a lot more power to spin up, or 7200RPM drives. In some cases they won't work, in others they might just take longer to start up as the motor can't bring it up to full speed as quickly. (Once it's operating, the power needed drops considerably.) A 2.5 inch SSD ought to work, too. There is probably a little leeway in the amperage of the USB port rather than it being only capable of exactly 500mA, so a brief draw a bit over that would be fine.

There's no way to know for sure about any particular cable without manufacturer's information or cutting it open to look at the wire size, but the ones that come with a device should be capable of what's needed. Of course the cheapest no-name stuff sometimes fails to meet expectations like that. A standard USB2.0 cable is supposed to be able to handle 1.5A at 5V (to support battery charging), but you'd want to get a quality cable to be sure you're not getting something that just barely meets the minimum specs. USB3 cables should have the same spec limit since the ports are only supposed to be 900mA, but most can safely go over that to 2A as a lot of ports/chargers provide more than the specification for faster charging of things like phones. And of course USB-C cables can handle a lot more.

One thing to note about plugging into two ports on a computer/console: the wattage/amperage from a single root port (in the chipset) gets shared amongst all the physical ports connected to that root port. Most PCs have two ports per root port (with multiple root ports in the chipset). So if two ports on the machine are both connected to the same root port and you plug the two connectors on the Y-cable to both ports, there is still only 500mA available. Unfortunately of many devices like a console there may be no way at all to identify the port configuration. On a PC you can use software to identify which root port a device is connected to, so you could move an enclosure from port to port to identify which ones are shared. So the two front ports on an Xbox 360 for example may be sharing a root port while the one on the rear is standalone.