First off, I am running Unraid 5.0-rc5 and it is working great.  I have been testing all of the various server options and have settled on Unraid, it fits what I need. 

 

I am running on old hardware that I had sitting in the closet.  My board is an Asus Limestone with a Pentium 4 3.0 GHz processor and 4 gigs of ram.  I have 2 1.5 TB data drives and 1 2 TB parity drive and will be adding 1 more data drive soon.  Currently fully powered up and running I am using 125-135 watts of power and with the drives spun down I am still around 100 watts.  I am using a Kill-a-watt to make the readings.  I am getting around 50MBs of data transfer to and from the system and am happy with that. 

 

I do not want to step down to an Atom board or something that will drop my throughput.  I am considering one of the many FM2 boards for a permanent build going forward, but I would also like to save a little power.  I do not really need it to go totally to sleep, but would like it to go into a fairly low power state since it is acting as a media server and backup host and is not extremely busy most of the time.  I will look for a board that I can undervolt, underclock and turn off cores at boot.  I am a fan of getting the best bang for the buck when I buy a cpu and motherboard, so I have a chance of extending the useful life of the product. 

 

I guess that I am looking for suggestions of hardware and indications of what power consumption levels I should realistically be able to get down to.

 

Thanks Matt

Most of the current 1155 CPUs from Intel are very power efficient.  the I3 is a very good bang for the buck. it is also very easy on the electric bill due to its low idle state draws. yet it has a nice amount of power for any sort of performance you request from it. perhaps you decide to ad a transcoding server to you server later on.

 

The 1155 pentium G lineup is also pretty good if you are on a budget.

 

As you mentioned, I would probably stay away from the current lineup of atoms out there due to their age and performance vs cost vs new i3 cost. the new atoms should be out soonish and those might offer a better bang for the buck.

 

as you have noticed, the P4 was one of the most inefficient CPUs intel made electricity wise. pour more power in it, make it run hotter and we can get another .1GHz! 

 

i am sure AMD has some combos that will fit your needs. I have not been keeping up with them lately. sorry.

Almost any new hardware will at least 1/2 that power consumption unless you are picking gaming parts. My old BE-2350 process with the 740G chipset runs around 50W and the Intel stuff can run at 1/2 of that. I don't know how the new AMD stuff is doing power wise, but pick lower powered parts and it'll be pretty good. I'm not sure where it was added, but the new RC software speed steps my AMD processor.