If I had one regret about my AM1 review that posted a few weeks ago, it was that I used a pretty hefty (relatively speaking) 500 watt power supply for a part that is listed at a 25 watt TDP. Power supplies really do not hit their efficiency numbers until they are at least under 50% load. Even the most efficient 500 watt power supply is going to inflate the consumption numbers of these diminutive parts that we are currently testing.
Keep it simple… keep it efficient.
Ryan had sent along a 60 watt notebook power supply with an ATX cable adapter at around the same time as I started testing on the AMD Athlon 5350 and Asus AM1I-A. I was somewhat roped into running that previously mentioned 500 watt power supply due to comparative reasons. I was using a 100 watt TDP A10-6790 APU with a pretty loaded Gigabyte A88X based ITX motherboard. That combination would have likely fried the 60 watt (12v x 5A) notebook power supply under load.
Now that I had a little extra time on my hands, I was able to finally get around to seeing exactly how efficient this little number could get. I swapped the old WD Green 1 TB drive for a new Samsung 840 EVO 500 GB SSD. I removed the BD-ROM drive completely from the equation as well. Neither of those parts uses a lot of wattage, but I am pushing this combination to go as low as I possibly can.
The results are pretty interesting. At idle we see the 60 watt supply (sans spinning drive and BD-ROM) hitting 12 watts as measured from the wall. The 500 watt power supply and those extra pieces added another 11 watts of draw. At load we see a somewhat similar numbers, but not nearly as dramatic as at idle. The 60 watt system is drawing 29 watts while the 500 watt system is at 37 watts.
So how do you get from a 60 watt notebook power adapter to ATX standard? This is the brains behind the operation.
The numbers for both power supplies are both good, but we do see that we get a nice jump in efficiency from using the smaller unit and a SSD instead of a spinning drive. Either way, the Athlon 5350 and AMD AM1 infrastructure sip power as compared to most desktop processors.