Hi everyone,

I need advice for building a case to hold all my IDE drives. I have
about 12 hard drives in external enclosures. To make space and save
power outlets I think it would be better to buy a computer case
dedicated to hold and store the hard drives. I will put about 7 hard
drives inside the case to start off... The supplies I would use are:

A computer case like this one (Rosewill R-9859 Black SGCC Steel ATX Mid
Tower Computer Case PL-300 Power Power Supply - Retail):
http://www.newegg.com/Product/Produc...82E16811147027
and install 3-4 additional 80 mm for HD cooling.

I would connect the two cables on the power supply mobo connector so it
will power the drives without needing a motherboard to give it the an
on signal. My friend says he knows how to set this part up (any advise
on doing this would help).

I would use a molex splitter (Converts one 4-pin Molex power connector
into four
http://www.microbarn.com/Power_Adapt...61-100881.html
) in order to have enough molex connections from the power supply for
all the hard drives and some fans.

For the IDE interface I would use seven of these USB 2.0 to IDE
adapters.
http://www.microbarn.com/ADA-UIDE--18-162-101149.html
I would connect the adapters to one USB 2.0 hub that will connect to my
computer.

With this procedure, I free up seven power outlets and turn them into
only one for the power supply. Additionally, I will only need to
connect one usb 2.0 port in order to have access to all seven drives.
And I will be able to carry all seven drives to someone elses house
with ease.

My concerns:
Will using the 300W power supply only for the hard drives via the molex
connectors push too much power to the drives causing damage to the
drives? Do I need a power supply with less watts or will it not matter?
Does anyone else think this can work? Is there anything I overlooked?

Any advise or corrections would be greatly appreciated.

Thank you,
Carlos

Previously Carlos / anifan115 <anifan115 (AT) gmail (DOT) com> wrote:
The potential damage is not to the drives. As long as they get the
right voltages, the drives decide how much power to draw. Basic
laws of electicity.

As to whether the PSU is large enough, that depends. If these
are newer, standard 5400 rpm or 7200 rpm drives, then about 25W
per drive should be enough power (they draw much more during
start-up than during normal operation). 25W * 7 = 175W. The
adapters and the USB hub should not matter. From the photograph
of the PSU label, I would say the PSU has both enough power and
anough current rating on the relevant lines (+5V and +12V).

Fro the USB-Hub, you should make that it can power the adapters
(i.e. it needs to be a powerd USB hub) and for easy combination
that you can also power it from the PC PSU.

You will in addition need to modify the on/off switch of the
PSY, since ATX PSUs are controlled by the mainboard and you
do not have one in there. For that you need to replace the
power switch in the case with a swithc with two stable positions
and use that to shorten out the power_on line towards ground
to activate the PSU. See any description of the ATX mainboard
connector on where to find these lines.

Arno

In message <1144989525.200783.104500 (AT) g10g2000cwb (DOT) googlegroups.com>,
Carlos / anifan115 <anifan115 (AT) gmail (DOT) com> writes

Your concerns are wrong.
Performance (if it performs at all) will be awful.
For multiple drives think SCSI - it can access the disks in parallel,
not serially. There are other advantages...

--
Jeremy Boden

I will probably have two power cables. One for the hub one for the psu.

Thanks for the advice!

IDE is fine for my needs, thanks.

Previously Jeremy Boden <jeremy (AT) jboden (DOT) demon.co.uk> wrote:
SCSI is cannot access drives in parallel. The bus is paralell, but
that does not offer a sped advantage. However the basic SCSI bus speed
is faster than that of USB, so you get more combines speed. And
if the OP only uses one of his disks at a time, the sped will jsut be
the same as if there was just one USB disk.

Arno

In message <4aaji7Fs2fnbU1 (AT) individual (DOT) net>, Arno Wagner <me (AT) privacy (DOT) net>
writes
you only access one disk at a time?
With SCSI:-
1) You can queue commands so you could send a series of requests for
data which will be serviced as data becomes available. This offers a
speed advantage.
2) Random access times are typically much better (faster/better drives).
3) There is virtually no load on the CPU, unlike the situation with IDE.

--
Jeremy Boden