1 computer, 9 HDDS

Captain Vash

So I've been working on this project.

I'm taking apart a pair of these Buffalo Terastations and turning them into a home server of sorts with 4tb of network attached storage..

So far I've taken apart 1 of my 2 NAS boxes and have successfully parlayed the drives into a 2tb raid array using windows 7 software raid.

My problem comes with the second set, by using every drive bay in the computer, I manage to have just enough space for all 9 HDDS (the 4x2 each raid array and 1 system drive for the host computer).. HOWEVER! I am at an impasse. I am out of 4 pin molex connectors to power my hard drives.

So the system is this:

Pentium 4, 3.0ghz single core w/ ht (stock clock speed)
2gb ram
9800 series ati AGP slot graphics card (will not be in active use, machine to be controlled via remote)
500w PSU
and then of course, the HDDS...

So, I see this going down 2 possible ways, Molex splitters (will I overload my psu with this many HDDS?) or shorting out one of the mini PSUs supplied with the Terastations (will this injure my drives / make the system unstable / do you know a good guide?)

Daedalus

Man, screw the connectors, can your PSU actually power that many hard drives with any amout of stability? How many +12v rails does it have (correct answer: one) and how many amps can it drive on that rail (correct answer: a shitload).

useless4

Are they sata or ide?

if they are sata I would just bite the bullet and go external esata array in an enclosure. I just bought a 8 bay with included esata card (which was crap, thankfully I already had a better one) for 349.

Captain Vash

They are, unfortunately, IDE.
Daedalus, I assume you are saying that my psu will only have 1, 12v rail, which I'm sure is correct given the age of the psu, and that the rail would need an insane amount of amperage in order to run all 9 drives, which I'm assuming it probably does not have. I can post more information about the exact psu when I get home from work today.
It's looking like, short circuit city for me.
Lucky me I have 2 spare PSUs to play with.

And while I was formerly in love with the set it and forget mentality of the enclosure, the tiny ass processor was not doing it for my read/write speed needs.

I've already tripled my performance the hdds that have been transplanted.

travathian

Hard drives don't requires that much power actually, except when they are initially spinning up. This is why RAID cards have options to delay spin up of drives in the RAID, so instead of all of them trying to turn on at once, it brings them online one after another. So if you have this option, use it. If you don't have this option, then yes, you may be screwed PSU-wise. You'd need to find out what the max draw is on each drive at start up, add them all up, and see if the +12V rail can even handle it.

Captain Vash

That's a very interesting option actually, you see, my motherboard bios has some raid related options. I may have to investigate.

edit: Anyone know of a reliable and accurate 12v rail requirement calculator?

travathian

Given you are dealing with 9 drives, I'd look up the information on the manufacturer's data sheets. Remember you need both spinup/peak and normal draw.

Ruckus

Also remember that the stated wattage on Power Supplies is often a Peak value, many aren't designed to operate constantly using that much power. The Operating Wattage could be 10-20% lower than the advertised peak wattage.

Captain Vash

So, the hitachi website states the peak max power draw of each drive is 15w.

15x9=135, which is well within the 420w my psu states is available for the 12v rail.

I can't help but feel like I'm missing something, the whole "omg more power" craze amongst gaming pc builders has me feeling like this many drives should require texan amounts of energy, but this rather basic math suggests I may very well have plenty of power, when you consider that the video card will never ever be under load, and the cpu is underpowered to begin with, and will probably never see peak use either.

GrimReaper

I'd be wary about those power calculations, a lot of psu's won't actually be capable of anything more than 80% of their advertised power output for any prolonged periods of time.

Also, if it's going to be just a server for storage i'd look at getting a low power passively cooled graphics card and maybe a low power processor too. With a Pentium 4 etc if it's not stored somewhere out of earshot you will get annoyed by the noise of the system with the fans, hard drives etc.

I built a cheapo file server for work a few years back using just IDE drives, be prepared for all sorts of weird issues.. especially if you've got more than one card in the pc to connect the ide drives to.

Ruckus

Captain Vash wrote: »

So, the hitachi website states the peak max power draw of each drive is 15w.

15x9=135, which is well within the 420w my psu states is available for the 12v rail.

I can't help but feel like I'm missing something, the whole "omg more power" craze amongst gaming pc builders has me feeling like this many drives should require texan amounts of energy, but this rather basic math suggests I may very well have plenty of power, when you consider that the video card will never ever be under load, and the cpu is underpowered to begin with, and will probably never see peak use either.

High-end gaming systems usually have a higher-power PSU due to the requirements of the Graphics Chipset(s), with some Cards consuming upwards of 100W each.

The Peak theoretical power on an ATI HD5850 board is 151W.

[edit] Jesus, the HD5970 max board power is apparently 294W.