R
rb
How well do the usb hard drives that are powered from the USB strip work?
I see a lot of 'em are this way, now.
I see a lot of 'em are this way, now.
P
philo
rb said:
They work quite well (as long as you use a USB2 port)
I bought a few from Newegg
B
Big_Al
philo said:
And I would add that you can buy empty cases to put old drives in, or
you can buy a new drive for them. Effectively making your own combo.
If you have a preference on size and manufacturer of drive (the real
guts of the device) then this is not such a bad idea. Some of the
already assembled USB drives I've seen come with unknown drive hardware.
Remember this is for the picky person, but it has its point.
Also note that 3.5 inch drives and cases, usually have an external
supply since the drive is larger and draws more power. 2.5 inch
drives/cases are made with laptop drives and usually draw less power and
can be powered off the USB port making them very portable, almost like
thumb drives. I have one of each.
One last feature is that when turned or of disconnected they provide
perfect isolation from a machine and viruses. Protecting you valuable
backups and data (not that data is usually infected... but).
This is more than you wanted but I'm a bit bored right now and wanted to
type.
O
Onsokumaru
He may also find some 2.5 in external drive leads come with two USB
connectors. This is in case the drive won't spin up, so you use two USB
ports to power the drive in that case. One of the leads is thinner than the
other as this only has connections to the power output of the USB port.
I've only used one, built using a laptop from an old HDD, and it worked
fine.
Some USB devices have problems when running from unpowered USB hubs, so bear
that in mind.
connectors. This is in case the drive won't spin up, so you use two USB
ports to power the drive in that case. One of the leads is thinner than the
other as this only has connections to the power output of the USB port.
I've only used one, built using a laptop from an old HDD, and it worked
fine.
Some USB devices have problems when running from unpowered USB hubs, so bear
that in mind.
P
Patrick Keenan
rb said:
It's actually the case, not the drive, you are referring to. You can buy
excellent cases starting around $25 and then use your choice of hard disk.
It takes minutes to set up. You can also buy cases that support multiple
hard disks with RAID and FTP functions and that have Ethernet ports.
There are two types of case. One has a separate AC power adapter, and
these are usually used with desktop-sized (3.5") hard disks.
The other type uses a special cable with three ends. Two of the ends attach
to USB ports, and one attaches to the drive. This is most often used with
laptop-size drive cases, and works well.
The three ended cable is necessary because a hard disk often draws nearly a
full amp of power.
In fact I've got a damaged 160 gig SATA laptop drive in front of me, and
it's rated at one amp. A couple of desktop drives in my desk drawer draw
about .75 amps at 5v and .5 amps at 12v (desktop drives use both voltages,
while laptop drives use only 5v).
USB ports, by spec, can provide no more than *half an amp* - 500m, so a
single port cannot supply enough power for these drives.
If you try to run a one-amp hard disk off a half-amp port, you won't have
positive results. Usually the protective circuitry shuts down the port
before damage is done, but you aren't likely to be successful. You may
have to shut down the machine and reset the BIOS to get the port back.
This also means that if you attach such a drive to a passive USB hub - one
that does not have its own power adapter - to one system port, you'll draw
too much power and the port will crash, at best. When purchasing powered
hubs, it is important to look at the power rating of the adapter. It has
to be over an amp.
HTH
-pk
S
smlunatick
Portable hard drives should not be left connected when not being
used. These are never intended to be powered on constantly and the
power supply will wear out faster.
S
smlunatick
Please note that most mobile hard drive were never designed to be
constantly powered on. You should disconnect when these are not in
uses otherwise the power supplies will fail early.
I
Ian D
Please note that most mobile hard drive were never designed to be
constantly powered on. You should disconnect when these are not in
uses otherwise the power supplies will fail early.
Either that, or the drives will eventually fail from running at elevated
temperatures for an extended time.