15w load on a ATX power supply?

[Sshaddoww]

Hi.
I wonder if it is a good idea to use a Fractal Design Integra 400w (Power supply based on FSP components) powersupply with a computer system that only peaks around 15 watts.
What will the actual power usage be with the full size power supply?

[CrazyNutz]

http://www.walmart.com/ip/14282370?w...l5=pla&veh=sem

[EniGmA1987]

That would not be a good idea, since the load would be less than 5% of capacity. If your computer system will run on only 12v, without the need for 5v and 3.3v rails then you should look into something like this:
http://www.automationdirect.com/adc/...s%29/PSS12-035

If you need all the power rails then you should look for something along the lines of this:
http://www.newegg.com/Product/Produc...82E16817129006

[stuffme]

Hi!

I'm sorry, this is not really an answer, but I've been looking into the same problem with my future plans for new low power NAS box. I was thinking of buying AMD kabini based mobo + cpu system which uses less than 10w in idle. If I would go for Intel bay trail, the idle power usage could be as low as 5w. The bay trail desktop models are available only at q2 2014. The kabini is also really rare and they have just begun to show on the stores, so still takes few weeks I guess.

Anyway, if I would build kabini NAS box with 4x WD RED 2-4TB dives, the system power usage would be 15-20w idle with power saving raids like snapraid, flexraid and unraid. If using raid modes where every disk is on all the time and no sleep mode what so ever, the power usage would be around 25-30w idle. The problem with thia low power usage is the PSU. There aren't really any option with good efficiency power units at those power draws. One would think that picoPSU is the way to go, but it's expensive and not much power cables for many hard drives(4-8). Even the efficiency is pretty lame considering 20w power output, see here http://www.jonnyguru.com/modules.php...tory4&reid=207. You get only measely 80% efficiency at 37w power draw. Think about how much lower it will be at 20w, let alone 10w power usage.

So far the best bang for the buck solution I've found is not great either at desired levels power levels, but at least there are some room for future if considering cables, maximum output and price. Seasonic SS-350TGM 80 Plus Gold TFX has 77% efficiency at 22w load and if more drives, your system could use 30-40w and then the efficiency would be around 84%. So clearly if space is no issue, this is way better option than any picoPSU. 150-200w gold PSU could hit right in the sweet spot efficiency wise at low power levels, but where are those?


So my guestion is, is there really any other option than this seasonic PSU?