Power Requirements for File Server

[DaCurryman]

OK guys, so I'm building a File Server for my home. Depending on whether or not I will pick up another 200gb HD, I will either have:

5 x 200GB (RAID5) = 800GB Storage
6 x 200GB (RAID5) = 1 TB Storage

I should also have either:

3 x 120GB (RAID5) = 240GB Storage
3 x 160GB (RAID5) = 320GB Storage

I will also have an additional drive (probably a 36gb Raptor) as an OS/boot and applications drive.

So I'm looking at possibly 10 hard drives plus a CPU/Mobo combo [either Athlon 2500 (have) or maybe an Opteron 165 (buy)], 1GB RAM, 64-128mb AGP Video Card, ATA133 Controller Cards (for all the HDs), 1 Floppy, and 1 CD/DVD ROM.

I'm wondering how large of a PSU I'm going to need to run all of this. I don't want to spend like $200+ on just a PSU. It might be better for me to move the 120/160GB RAID array to another machine.

I'm looking at a Lian-Li case right now if that helps at all (since they make enough space for all the HDs). I'm open to any and all suggestions on PSUs. Thanks in advance.

 

[Fullmetal Chocobo]

I've talked to lots of people in RAID, and most have something around 500 watts in a good brand to power a setup like that. So if you get a 500, and don't plan on having dual video cards or something like that, you should be alright. I have 6x250 (RAID 5), 2x160 (RAID 0), and two 120's in my system, but I'm running dual Xeons which drink electricity, so I went with a dual PSU setup. But I don't think that will be required for you. Your best best would be to get a Seasonic S12 600w or Fortron 600w, and you'd be set.

 

[DaCurryman]

I was actually wondering if dual PSU setup was possible. I havent seen any Mobos or Cases that accomodate 2 PSUs. Would it be better to have like 2 PSUs at like 350-400W each or have a single 600W PSU. The higher watt PSUs seem to cost much more than 2 smaller PSUs. Which one would be more reliable?

 

[Fullmetal Chocobo]

Well, you can just mod a switch to the second PSU (to the green and a black pin), and that turn the PSU on and off. You have the secondary PSU powering fans and all the hard drives (with the exception of the boot hd), and it works well. With the processor that you are running, I don't think the dual is required, but it wouldn't hurt either.

What you could do is get one, and then if you start having problems, or your rails are dropping, then get another one.

 

[Zap]

Why don't you minimize your power requirements by using larger hard drives? Get four 500GB drives on one RAID 5 array with 1.5TB space, giving you 180GB more than your 6x200+3x160 and using only four drives instead of nine. If the price premium is too much, go with four 400GB drives for 1.2TB storage space. Heck, Fry's has these 400GB beauties for $159AR this weekend. Spend a few bucks more on the higher capacity drives and you can save money on the PSU, huge case and extra RAID controller.

 

[DaCurryman]

Originally posted by: Zap
Why don't you minimize your power requirements by using larger hard drives? Get four 500GB drives on one RAID 5 array with 1.5TB space, giving you 180GB more than your 6x200+3x160 and using only four drives instead of nine. If the price premium is too much, go with four 400GB drives for 1.2TB storage space. Heck, Fry's has these 400GB beauties for $159AR this weekend. Spend a few bucks more on the higher capacity drives and you can save money on the PSU, huge case and extra RAID controller.

I would consider that except that I already have 5x200GB HDs.

 

[Fallen Kell]

You really don't need dual power supplies... The only reason for them would be for redundancy (things like high uptime requirements, with one power supply on an UPS or similar and the other on a completely different circuit).

But I don't think you need a setup like that. Go look at the actual power requirements from your drives...

For instance:

A WD 36GB raptor needs:
.35 Amps 12V
.8 Amps 5V
8.5 Watts

A WD 320GB Caviad RE SATA needs:
.45 Amps 12V
.8 Amps 5V
9.5 Watts

A WD 200GB Caviar SE SATA needs:
.45 Amps 12V
.8 Amps 5V
9.5 Watts

So multiply by number of drives: 6x 200GB, 3x320GB and 1x36GB gives a grand total of:
4.4 Amps 12V Rail
8.05 Amps 5V Rail
94 Watts power from the power supply.

Now using that, you can figure out what size power supply you really need. Go to AMD's website and find the max power draw from the processor you want and go to your motherboard's website and find its power draw for the motherboard and finally find the power requirements on the video card you are looking at using. Add up those numbers as well for the individual rails so you know what Amperage rating each rail needs to meet, and total wattage. Now you know roughtly want requirements you have. Just for reference, a system memory uses about 30W of power, tests on AMD Athlon64-4000 Clawhammer (more power hungry then any other core) was 74W, for video card ~140W-190W:

Video Card 1: Gigabyte 6600 GT Silentpipe II (130W)
Video Card 2: Gigabyte 7800 GTX Turbo Force (145W)
Video Card 3: eVGA 7800 GTX Black Pearl (158W)
Video Card 4: SLI Asus 7800 GTX Extreme (188W)

The video cards were measured by compairing known power draw from the system without the card with the system with the card in it, with full power being calculated from benchmarking against running F.E.A.R....

So do the math, don't just buy the biggest thing you can think of, you REALLY don't need it. In fact, VERY few people need more then a true rated 450W power supply with the proper amperage on the different rails.

 

[Fullmetal Chocobo]

Staggered spin up will greatly reduce the power required by the setup. When the drives kick on for spin-up when you first turn on the machine, that is when you have the greatest power draw. If you can stagger them (if the controller & drives support it, and you have it enabled), then it helps a lot.

 

[DaCurryman]

WOW! Thanks a lot for the help guys. I didnt realize that I could find the exact wattage needs on the HDs site or box. So I'll def have to look into that to see how much I need.

As for the staggered spin-up, how does that affect the system? The drives that arent spinning when booted...wouldnt those not get recognized by the system/OS? Also, how would the RAID array be affected if 1/2 the drives are spinning and the other arent right away?

 

[Fullmetal Chocobo]

If you have an external (read: non-integrated) RAID controller, it gets control of the system after BIOS. After all of the drives spin-up, and it double checks the drives & RAM, it then passes control to the operating system. Staggered spin-up simply spins a specified number of drives up at a time. So I have mine set to 3, so it spins up 3, then the next 3, then the other 2. All of the drives are available for the OS by the time they are finished spinning up. Remember, this is only for the system powering on/booting. Thus it doesn't affect the operation of the drives or RAID arrays whatsoever after the OS comes up.

 

[DaCurryman]

Originally posted by: Fullmetal Chocobo
If you have an external (read: non-integrated) RAID controller, it gets control of the system after BIOS. After all of the drives spin-up, and it double checks the drives & RAM, it then passes control to the operating system. Staggered spin-up simply spins a specified number of drives up at a time. So I have mine set to 3, so it spins up 3, then the next 3, then the other 2. All of the drives are available for the OS by the time they are finished spinning up. Remember, this is only for the system powering on/booting. Thus it doesn't affect the operation of the drives or RAID arrays whatsoever after the OS comes up.

Since I wont be writing to the disk continuously, I was planning on using the hack to allow Windows XP Pro to allow for a RAID 5 configuration, so it would be a software based RAID system. I thought about getting the HighPoint RocketRaid 464 card, but decided against it in order to keep my costs down. So the controller cards, I was planning on were regular ATA133 controller cards, since the mobo wont have enough IDE slots for all the HDs. This way all my HDs would be connected and WinXP would be the software RAID 5 controller.

Do regular ATA133 controller cards allow staggered spin-up?

 

[Fullmetal Chocobo]

Originally posted by: DaCurryman

Originally posted by: Fullmetal Chocobo
If you have an external (read: non-integrated) RAID controller, it gets control of the system after BIOS. After all of the drives spin-up, and it double checks the drives & RAM, it then passes control to the operating system. Staggered spin-up simply spins a specified number of drives up at a time. So I have mine set to 3, so it spins up 3, then the next 3, then the other 2. All of the drives are available for the OS by the time they are finished spinning up. Remember, this is only for the system powering on/booting. Thus it doesn't affect the operation of the drives or RAID arrays whatsoever after the OS comes up.

Since I wont be writing to the disk continuously, I was planning on using the hack to allow Windows XP Pro to allow for a RAID 5 configuration, so it would be a software based RAID system. I thought about getting the HighPoint RocketRaid 464 card, but decided against it in order to keep my costs down. So the controller cards, I was planning on were regular ATA133 controller cards, since the mobo wont have enough IDE slots for all the HDs. This way all my HDs would be connected and WinXP would be the software RAID 5 controller.

Do regular ATA133 controller cards allow staggered spin-up?

If you are talking about an add-in card (PCI, PCI-e, PCI-X type), then it depends upon the card. You just have to look at the specs on the hardware that you are getting... It will be listed among the features of the RAID card. Online array expansion is a wonderful feature to have as well.