questions related to PSU for atom based mobo

[kiranghag]

Just got my dual atom mobo and a compact SMPS. the smps is 250W model

need to know

- how to measure actual power consumption of this setup (monitor excluded) using a DMM that supports current measurement. I know how to do this in theory but wondering if someone can post pics about it

- i keep reading that existing ATX SMPS are not great to use with atom based mobos because at lower loads they tend to be less efficient.
with my 250watts SMPS, will it be more efficient than the standard ATX SMPS?

 

[Modelworks]

No pics, but I usually use an old extension cord for this. Cut one wire on the cord and then connect that through the appropriate points on the meter so that the power for that wire flows into and then out of the meter. Set meter to correct setting. Plug in device you want to measure into the cord, then plug in the cord to the AC outlet.

Make sure your meter is rated to handle the load. Most are good for at least 10A but double check.


Don't worry about the difference in efficiency with something like a atom setup. It isn't enough to worry about.

 

[Zap]

Hello, kiranghag, and welcome to Anandtech Forums.

I find these devices to be handy because they are easy to use.

You are correct in that most PSUs become inefficient at low outputs. It all depends on what your goals are. If your goal is to do the least amount of power draw possible, then you will want to find out what your Atom rig takes (some as low as 30W for a complete system) and then purchase a super low wattage PSU for it (such as a 60W PicoPSU). If you just want "low enough" power draw, then don't worry about it. Even if inefficient, an Atom based computer with a higher wattage PSU probably will still never break 100W power draw.

 

[kiranghag]

thanks for the welcome...

I am in India and did not find indian version of kill-a-watt around..
pico psu is available (though at little higher price) but I wanted to find out if I am gonna exceeding its rating.

the goal is to use least power - this box is going to be on 24/7. its not much loaded though - GCLF2 + 2GB RAM + Seagate 320GB SATA HDD + Keybaord + Mouse + external intex USB TV tuner. would like margin for internal IDE DVD Writer/external USB Pen drive which I can connect occassionally.

I am going to buy a cheaper version of clamp meter available here and take its reading with some salt!

hope that would work well...