I have a norco 12 drive system (10 attached) based on an AMD Phenom 1045T.  Had a PSU failure (7 years old).  It was a 2U 450w Athena Power with a 26A 12v rail

 

I had a 400w ATX, 25A Rail coolermaster just laying around, so I rigged it up, since it doesn't physically fit in the case.

 

I know alot of people prefer to go with 700-1000W PSUs, but I am curious if anyone is running anything in the 300-400W range with a dozen drives?

 

My KillAwatt meter only shows usage of about 140w, 

 

 

In the near future, I plan to move to a norco 20 bay case (Standard ATX size).  I will likely go with a 700-800w PSU with a 50-60A 12v rail so that I can support a GPU and 20 drives

 

 

1 hour ago, wisem2540 said:

My KillAwatt meter only shows usage of about 140w

Was this measurement taken during a parity check?

Or during disks spinup, which will be peak power used, though difficult to measure exactly with killawatt it will be much higher than that, I estimate around 300W, while I feel many go overboard with the power supply, for 10/12 disks I use a 500W PSU

I monitor my power quite closely when making hardware changes - I run 12 hard drives in each server using 430 and 450W power supplies with no issues.  With a variety of power meters I only see just of 200W at the start of the drives spinning up.  Even if I miss the absolute peak measurement because it's quite short, I am pretty sure that I am below 300W peak.  I should point out that the rest of the hardware is pretty basic - no graphics cards, for example.   The 450W was replaced (from a 430) about 18 month ago.  Power supplies do age, and I would not reuse an old power supply in a new server build.

Edited December 4, 20187 yr by S80_UK

the PSU will idle at a lower watt usage at most times, but u will need lower watt CPU. Thats what will bleed your utility bills the most. U cannot help with the HDD's though, at any time 6watt will be for each drive attached to ur server.

If you are not running multiple graphics cards, then stick with the lower wattage power supplies. 400-450 watt sounds just fine for you. Power supplies are in their peak efficiency around their mid-point of output, so try to keep your power-supply sized as close to your average demand as possible, while still staying within your peak demand. For example, I have a dual processor e5-2670V1, 11 HDD and 3 SSD, GTX 1050 Ti and 7850 HD and do just fine with a 750 watt. It is higher than needed for my average demand but within my peak demand. Server typically sits around 200 watts.

Thanks for the feedback guys

My advice would be to look at several of the psu calculators that can be found here:

 

https://www.bing.com/search?q=coolermaster+psu+calc&form=EDNTHT&mkt=en-us&httpsmsn=1&refig=3a5686a1e094472affe20f60e8cf6e3c&sp=5&ghc=1&qs=AS&pq=coolermaster+&sk=SC3AS1&sc=8-13&cvid=3a5686a1e094472affe20f60e8cf6e3c&cc=US&setlang=en-US

 

 and look at an average of several. There are a lot more components that go into deriving power requirements than the number of drives. Not something you want to be on the wrong side of.