Need Help for Multi-Drive Computer Case Enclosure Setup

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 a

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

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?

No. More watts will never damage the drive. These watts mean the _PSU's ceiling
ability_, not the real power supplied to a drive.

The power supplied to 1 drive depends only on voltages, which are always +-5
and +-12 V.

The PSU's power is only "interesting" in a way it must be then the total
power consumption for all drives, otherwise, the thing will work very bad or
not work at all (fail to start).

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation

http://www.storagecraft.com

Thanks!

Carlos / anifan115 wrote:

....

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?

Possibly that the 300W power supply will be inadequate.

Recent Seagate 3.5" ATA drives specify a 2.8A (presumably, max) start-up
current from the 12V supply. Seven such drives could conceivably
require close to 20A from the 12V supply at at least some point during
start-up - a value which a 300W supply may well be unable to furnish (my
limited acquaintance suggests that they're typically specified as
supplying something like 12A - 15A, though with the higher 12V currents
demanded by recent processors that may have changed). For this reason
most large server systems use a 'staggered start-up' arrangement (often
implemented in the disk/array controller) where each drive is spun up
separately at a slightly different time. Once spun up each drive
requires well under 1A for continuous operation from both the 12V and 5V
lines (at least that's what my drive says on the case, though the
average might go up some in seek-intensive applications).

- bill

Possibly that the 300W power supply will be inadequate.

Standard for usual desktops these days. May be to small for a server/disk
array.

demanded by recent processors that may have changed). For this reason
most large server systems use a 'staggered start-up' arrangement (often

Most SCSI disks allow so.

--
Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation

http://www.storagecraft.com