Building a NAS, need advice for PSU

peterson · Post by **peterson** » Fri Sep 18, 2009 7:05 am

Ok, to start with, i HAVE searched the forum, but not all of it, so if anyone already has posted similar, please give me the link thank you.

Allright.
So i'm going to build a NAS with FreeNAS as 'OS' out of spare parts.
I have a Gigabyte 780G board and a BE-2350 CPU. I intend to disable sound etc that i won't need, and also underclock/undervolt it heavily. 2GB DDR2 RAM.
I will use a CF-card as my systemdisk, and 3-5 1TB HDDs as my storage in RAID 5.
I will probably install a wifi-card in there as well, but nothing more. Unfortunately, i won't be able to stow it away and thus minimize noise. It will be in my livingroom.

I was hoping i could use a Pico PSU to power it, but i understand it may not work. Since i don't have the knowledge of what'll be the optimal, i post this question here.

What do you recommend?

Really thankful for any input that'll help me get a small and quiet PSU. I understand that FreeNAS can spin down the HDDs and also stop them when necessary. So they won't spin at full speed all the time and therefore may not be the biggest source of noise.

Thanks

electrodacus · Post by **electrodacus** » Fri Sep 18, 2009 8:36 am

I have no idea how much power the motherboard will use the CPU is a 45W TDP not to much problem and I do not know what HDD. Do you have them or you need to purchase?.
I will recommend this http://www.wdc.com/en/products/products.asp?driveid=559 if you need to buy.
I guess that my power supply will work with your system but I need more info maybe you did some power consumption measurement.
See this viewtopic.php?t=55153 for more info about my power supply.

peterson · Post by **peterson** » Fri Sep 18, 2009 9:14 am

The CPU shall be underclocked so i suppose it will be far from 45W.

The HDDs will probably be Samsung F1s, as i already have 2.

I will check your links thanks

Metaluna · Post by **Metaluna** » Fri Sep 18, 2009 12:10 pm

I would expect a system like that to idle in the neighborhood of 50W, especially if underclocked. I put together a similar system a while back, except the CPU was a 5050e, not underclocked, and I think I had it idling around 60W. For HD's, I had 3-4 WD 1TB Greens.

electrodacus · Post by **electrodacus** » Fri Sep 18, 2009 9:41 pm

peterson wrote:The CPU shall be underclocked so i suppose it will be far from 45W.

The HDDs will probably be Samsung F1s, as i already have 2.

I will check your links thanks

Ok if I consider MB to be 25W idle and 35W load + CPU 10W idle and 45 load Samsung F1 7W idle and 12W load x 4 Then I get system idle 25W+10W+(7Wx4)= 63W idle and at load 35W+45W+(12Wx4)= 128W
In the worst case at load will need 128W this is more than 120W max continues power except the 5VSB so it will be a bit overloaded (it will probably work) but I do not want to recommend this power supply if you do not undervolt the CPU or use more power efficient HDD or better both

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