Re: External Hard Drive Recommendation

Dave Martindale wrote,

Two cables, or one cable with two USB "A" plugs to obtain enough power
for the drive?

On their website, it appears the unit has one mini-USB slot on the drive
case, which makes me believe that what you describe above is the case. On
another forum, a person commented that it was a good drive but he didn't
realize, nor did Seagate make it apparent, that he needed two USB ports on
his computer.

I have several 2.5 inch drives in external cases, and all theoretically
use more than 0.5 A under some conditions. I've had some experience
with them now, and I *do* have a double-plug cable that came with one of
the drives, but I've found that I don't need it most of the time. In
particular:

1. The motherboard USB ports (Asus P5K MB) provide sufficient current
from a single port for all of my drives, provided the cable is up to
snuff (see below).

2. The USB ports on my Gateway laptop also provide sufficient current
from one port to power the drive.

3. Several different external USB2 hubs, with their own 5 V power supply
wall warts, do *not* provide enough current from one port - they will
shut the port down.

As for cables, you need a cable that does not produce much voltage drop.
The short (6 inch) cable that came with the WD Passport drive is fine,
but that means putting the drive 6 inches from the port - OK for laptop,
not for desktop. I also have a ~6 foot long USB cable where the
pair of wires that carry power are 20 AWG (signal pair is 28 AWG) which
also works fine. But many cheap USB cables use 26 or 28 AWG for both
power and data, and those do *not* work - too much voltage drop.

In summary: if you use the motherboard USB ports (not a hub), and have a
suitably heavy cable, you may find that you don't need the double-plug
cable.

This is all interesting information. Thanks for the detailed explanation.
I am going to research what the power output of my USB ports are on my
Thinkpad.

rg


.

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