I Have a WD Passport. It came with a very short USB cable. (about 30 centimetres)
I have a 3 metre long usb extension cable which is ‘supposed’ to transfer power as well as signal.
I plugged the Passport into that. It refused to work at all.
I then plugged it into a metre long ‘standard’ USB cable (not an extension, just a longer version of the one I got with the passport)
it worked, but it took about two hours to copy 4 gigs. (Windows Vista)
I then tried using the short 30cm cable. It took about ten minutes or less to copy the same amount of data!
So is this cable length? Could it be fragmentation (windows vista says none of my drives need defragginig) or is it possible my shiny high-spec PC has USB 1.0 slots?
What’s the SD GQ on this?
ETA: The WD Passport uses the USB’s power. It doesn’t have an external power source.
Yes, USB length is limited to 16 feet. Your cable should work, but cable and USB chipset quality vary quite a bit. I would return the cable for a replacement if I was you.
Longer cables suffer from interference and voltage drops. I wouldnt be surprised that you would need a short cable to get the full 2.0 speed.
Edit: A little google produces the fact that powered devices (what the usb consortium calls low speed devices) cannot exceed 3 meters. You probably will need to go a little shorter to even get power if the cable is low quality.
It probably uses more power. Ipods are flash or microdrive based, while a usb drive like yours is probably just a laptop drive in an enclosure.
They make usb cables that are dual-headed. One end plugs into your drive and the other into 2 usb slots. One for data/power and another for just power. Dunno if it will fall back to USB 1.1 speeds or retain 2.0 speeds.
I find USB is a terrible solution for this kind of thing. If you need a farway disk best to use something with a 1 gig ethernet interface.
The power conductors in a USB cable are 20 to 28 AWG typically. For a 3 meter cable that is a .2 ohms to 1.3 ohms per leg. The max current of USB is .5 Amps. So that is .2 V to 1.3 V drop (including the drop on power and ground leads). The short cable (30 cm) is 1/10 that. If you have a long cable with 28 AWG I can believe that the drive is not getting enough power to operate.
I have similar issues with external USB powered drives. Short cables work great. Some long cable work some don’t.
It’s not “cable quality” at all. I have high quality 3 meter USB cables and they refused to work with USB powered drives. Self powered USB drives should be operated with nothing exceeding the length of the factory cable. They are pulling operating power from the USB port, and as this power is fairly meager to begin with throwing a big chunk of copper between the drive and the USB port in the form of a long USB cable screws up these tolerances considerably.