20 hdd capacity build PSU recommendation

[jbm715]

I am looking at building a tower with up to 20 hard drives. It is heavily based upon a build at Greenleaf Technology.

 

Build so far:

Case : Antec 1200

HDD Cages: NORCO SS-500 5-Bay x2 (for now)

 

Motherboard : SUPERMICRO MBD-X9SCM-F-O

CPU : Intel Xeon 1230 Sandy Bridge 3.2GHz

RAM : Kingston 8GB (2 x 4GB) DDR3 1333 ECC

 

Controller: IBM m1015 x1 (for now)

 

Parity: WD Red 3tb

Cache: WD Black 1tb

Data:  2x WD Red 3tb, 2x WD Green 2tb (already owned), 1x Seagate 2tb (already owned)

 

The build recommended a 650W PSU; however, I have a feeling that recommendation didn't take into account using virtual machines.  I'd like to use the VirtualBox plugin to run a number of VMs for a Counter Strike GO server, minecraft server, backup sabnzbd, sickbeard, couchpotato vm in case of issues with plugins. Would a 650W PSU suffice or should I look to getting a beefier one? I should probably up the memory too now that I think about it.

 

 

 

 

 

 

[burtjr]

Your virtual server will still be using the components in your build and should not add to the power draw. If I'm not mistaken Greenleafs build is based on green drives. If you add reds or other 7200rpm drives you may need to bump it up.

[jbm715]

You are right. My attention to detail failed me there  .  I have a spare 950W 80plus bronze laying around, but I think that is too much for being always on.  I might breadboard my setup without any drives then start adding Western Digital Reds, checking the pull with a kill-o-watt. Estimate how many 20 reds would be.  Thanks for the reply!

[Chugiak]

That 950W PSU won't be cranking out that much power 24/7, it will be limited by what the system needs at any given time.  The only concern you should have for that PSU compared to a 650W PSU is what efficiency will they have for a likely power draw of ~300W?

 

If your electricity is expensive, it may be worth the effort to purchase a more efficient PSU rather than a powerful PSU.

 

I'd love to see what Red drives draw at the wall.  God bless the kill-a-watt! 

 

[Edit to add...]

I checked out the WD specs page for the red at http://www.wdc.com/en/products/products.aspx?id=810

The 3 TB has a 4.4 W power dissipation for read/write operation.  Even if you used a conservative estimate of 10 W per drive that's only 200W that you need to provide for the HDDs.  The trick is getting all that off the 12V single rail.

 

For 20 Red HDDs, you need a PSU that can provide the following:

 

20 x 0.250 amps of 12V = 5 A

 

20 x 0.280 amps of 5V = 5.6 A

 

Something like this Seasonic 650 W has more than enough juice to cover the hard drives, motherboard and CPU.  As long as you don't throw in a beefy GPU you should be good to go.

 

My OCD now compels me to run some numbers on how much energy it could take to power your system for a year.  Let's suppose that your system has an average power need of 200 W.  If you use a 950W PSU 80 Plus Bronze, you're looking at about 82% efficiency (see Wikipedia for the details).  So from the wall you're pulling ( 200 W / 82% ) = 244 W.  In a year that amounts to 2137 kilowatt-hours (kWh).

 

A 650 W 80 Plus Gold PSU would likely be hitting about 90% efficiency, which results in about 222 W from the mains.  In a year that amounts to 1947 kWh.  That's a difference of 190 kWh in a year.  Over five years that amounts to 950 kWh.  In my neighborhood a kWh costs about $0.13, so the difference in electricity saved amounts to $123.50.  So a gold PSU in the 650 W range could pay for itself in 5 years over a bronze PSU.

[Ford Prefect]

[Edit to add...]

I checked out the WD specs page for the red at http://www.wdc.com/en/products/products.aspx?id=810

The 3 TB has a 4.4 W power dissipation for read/write operation.  Even if you used a conservative estimate of 10 W per drive that's only 200W that you need to provide for the HDDs.  The trick is getting all that off the 12V single rail.

 

..not quite right.

These values are during operations...the PSU must also support the power-draw during a cold start.

Here even the green drives draw up to 2A....other 7.2k drives draw 3A.

[PeterB]

The build recommended a 650W PSU; however, I have a feeling that recommendation didn't take into account using virtual machines.

 

You're supplying power for physical hardware, not virtual hardware - the 650 watt PSU should still be adequate, provided that you stick with mainly green/red drives.

 

Remember that you need to be able to supply sufficient current (amps) to spin up all the drives simultaneously, but for most of the time the drives will not be spinning.  A PSU is at its most efficient when running between 20% and 80% of full load, and if you oversize the PSU your system will be idling at, or below, that 20% point.  I can strongly recommend Seasonic X-series PSUs - they turn the fan off when operating at below 25% load, reducing noise and power.  The X650 or X660 should be a good match.

 

One other comment - if you're looking at high processing loads on your other VMs, then why not consider the Ivy Bridge CPU (e1230v2), not only is it slightly more powerful, but it's also more energy efficient.  However, the bigger benefit may be the ability to use faster RAM - 1600 rather than the 1333 which the Sandy Bridge is restricted to.  It is compatible with the mobo you've selected - provided that it is running a v2 BIOS.

[Chris Pollard]

Seem to remember seeing one of my drives had a rating of 20W for power up.  Certainly the seagate drives are all between 6-8W operating in the specs.

 

When my system had 18 drives it drew 201W on boot, 105W idle and about 180w while doing a parity check... (from a kill-a-watt)  thats with the specs in my build below.  I haven't rechecked it since filling up all the slots and swapping out the CPU for one with a bit more juice.

[Chugiak]

..not quite right.

These values are during operations...the PSU must also support the power-draw during a cold start.

Here even the green drives draw up to 2A....other 7.2k drives draw 3A.

 

Thanks for that reminder FP.  I spaced out the cold start-up power draw.  The WD web site has a PDF datasheet that is a little tricky to get to, but this link should be good: http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-771442.pdf

 

It shows under power management a peak of 1.73 A on 12V.  That looks like the cold spinup, as it equates to 20.76 W.

 

In looking at the specs for the X series PSU from SeaSonic that PeterB recommends, it looks like the latest versions have 10 SATA power connectors instead of the 8 of the prior version.

 

So, to sum up for jbm715, his system will have the following power draws:

 

20 x HDD such as the WD Red 3 TB = 415 W peak on the 12V rail

CPU = 80 W peak (TDP spec)

Motherboard and RAM = (any guesses?  I'll use 20W )

CPU and case fans = 15 W (depends on fan quantity and quality, ~2.5W for a 140mm fan seems typical)

 

Adding up the above, the PSU should be able to deliver a peak of at least 530 W.  In particular, in addition to powering everything else it should be able to deliver at least 35 A on the single 12V rail.

 

Thus it would seem that a high quality 650 W PSU is more than sufficient to meet the needs of the system as specified.  To further improve power consumption, a 80 Plus Gold rated PSU will save something in the range of $10 to $20 per year over a comparable Bronze PSU.  Finally, it should be noted that the SeaSonic X650 PSU has a 7 year warranty.  I think I've just specced out my next PSU. 

 

[prostuff1]

For our 20+ builds we usually go with the TX750 or TX850.  It might likely be a little overkill but we want to make sure that power (or lack there of) is NEVER going to be a problem.

[jbm715]

Wow y'all. Thank you for all the replies!  I went ahead and bought the Seasonic 650.  I'm also glad that it is modular. I'm horrible at cable management so that definitely helps.  I went ahead and breadboarded everything to make sure the cpu/mobo and hdds weren't DOA.  That Norco SS 500 cage sounds like a small plane. Definitely going to buy replacement fans for it.  Again, thanks for the help! 

 

 

One other comment - if you're looking at high processing loads on your other VMs, then why not consider the Ivy Bridge CPU (e1230v2), not only is it slightly more powerful, but it's also more energy efficient.  However, the bigger benefit may be the ability to use faster RAM - 1600 rather than the 1333 which the Sandy Bridge is restricted to.  It is compatible with the mobo you've selected - provided that it is running a v2 BIOS.

 

 

I went with that particular CPU because there was a combo deal with the mobo on newegg

[Ford Prefect]

..not quite right.

These values are during operations...the PSU must also support the power-draw during a cold start.

Here even the green drives draw up to 2A....other 7.2k drives draw 3A.

 

Thanks for that reminder FP.  I spaced out the cold start-up power draw.  The WD web site has a PDF datasheet that is a little tricky to get to, but this link should be good: http://www.wdc.com/wdproducts/library/SpecSheet/ENG/2879-771442.pdf

 

It shows under power management a peak of 1.73 A on 12V.  That looks like the cold spinup, as it equates to 20.76 W.

Yes...here's the datasheet for seagate drives: http://www.seagate.com/files/staticfiles/docs/pdf/datasheet/disc/barracuda-desktop-hdd-ds-1770-1-1212us.pdf

It shows 2.0 to 2.5A (although I remember the 3TB barracuda were being rated at 2A previously  )

The difference of 0.27A per drive is not much, but for 20 drives it still adds up to 5.4A 

 

Thus it would seem that a high quality 650 W PSU is more than sufficient to meet the needs of the system as specified.  To further improve power consumption, a 80 Plus Gold rated PSU will save something in the range of $10 to $20 per year over a comparable Bronze PSU.  Finally, it should be noted that the SeaSonic X650 PSU has a 7 year warranty.  I think I've just specced out my next PSU. 

Bronze and Gold are good for a range around 40-80% of the nominal load.

You should even consider going for a platinum rated PSU in order to save money on your electricity bill.

These PSUs keep efficiency rates even on lower power levels (down to 20% of nominal load) and on higher levels (up to 90% of the load)

The lower range is for your server on idle, which is where it will be most of the time.