Power Supply question

[oktokie]

I am going to build ATA RAID5 storage using Dell Optiplex GX150(079WPJ
DELL 200 WATT ATX POWER SUPPLY) + Promise FastTrak SX4000 + qty.4 x
WD800 5VDC 0.80A / 12VDC 0.45A.
*May be a CDROM, but CDROM can be removed after building a storage.

Does anyone know how to calculate power requirement for driving qty.4
X WD800 hard drives?
Will 200Watts powersupply give ample juice? or needing to upgrade to
300Watts?

Can someone show how to calculate power requirement?

If you know how to calculate BTU based on power for cooling
requirement, then please, reply.

Thank you.

 

[Rod Speed]

I am going to build ATA RAID5 storage using Dell Optiplex GX150(079WPJ
DELL 200 WATT ATX POWER SUPPLY) + Promise FastTrak SX4000 +
qty.4 x WD800 5VDC 0.80A / 12VDC 0.45A.

*May be a CDROM, but CDROM can be removed after building a storage.

Does anyone know how to calculate power requirement for driving qty.4
X WD800 hard drives?

There isnt any easy way, essentially because what matters isnt the
simplistic wattage rating, its the surge currents at startup and that
data isnt even available with the cheapest power supplys, and that
current varys quite a bit with any model hard drive from copy to copy,
so you just have to be very conservative with so many starting at once
if you cant have the controller bring them up in sequence spinup wise.

Will 200Watts powersupply give ample juice?
or needing to upgrade to 300Watts?

There's a lot of variation in the surge current capability
with superficially identical wattage power supplys.

Can someone show how to calculate power requirement?

You have to use the worst case startup current from the drive
manufacturer's data sheet, multiply that by the number drives
if you cant sequence the drive spinups, and then ensure that
that is below what the power supply specs say the power
supply can supply.

If you know how to calculate BTU based on power
for cooling requirement, then please, reply.

Again, not even possible. What matters much more is
whether there is a free slot between the drives, and if
there isnt, what is used to move the air over the drives.

 

[oktokie]

There isnt any easy way, essentially because what matters isnt the
simplistic wattage rating, its the surge currents at startup and that
data isnt even available with the cheapestpowersupplys, and that
current varys quite a bit with any model hard drive from copy to copy,
so you just have to be very conservative with so many starting at once
if you cant have the controller bring them up in sequence spinup wise.


There's a lot of variation in the surge current capability
with superficially identical wattagepowersupplys.


You have to use the worst case startup current from the drive
manufacturer's data sheet, multiply that by the number drives
if you cant sequence the drive spinups, and then ensure that
that is below what thepowersupplyspecs say thepowersupplycansupply.


Again, not even possible. What matters much more is
whether there is a free slot between the drives, and if
there isnt, what is used to move the air over the drives.

Please, refrain yourself from posting if you don't know what you are
talking about.

If you did not want to a

 

[Rod Speed]

Please, refrain yourself from posting if you don't know what you are talking about.

Go and **** yourself. No please, thats an order.

If you did not want to a

You can get medication for premature ejaculation apparently.