I've just finished my new main pc. I use it mainly for office, web browsing/downloading, play music, video encoding, burn dvds, retouch photos. No games.
My goal was to have a powerful pc wiht a low power consumption (to "stay green" and save the bills). Previously I had an atom 330 rig but atoms are just too weak for some task, expecially image editing and video encoding.
In choosing the components, I did focus on price and low-power specs. I decided to go AMD, because of low price and good reviews for the Athlon II here in Silentpcreview. I was surprised for the very frugal consumption of this rig, with a little undervolting.
This is the pc I made, and some tests:
*update. A closer wiew to the MoBo with the Picopsu 120-WI.
The first step was with a "standard" non-80+ psu. After some days I swapped the psu for a picopsu 120-wi. I measured the power consumption with kill-a-watt.
CPU: ATHLON II 240 "REGOR" 2800MHz - Motherboard: Gigabye 785g (GA-MA785GM-US2H) / 2gb kingston DDR2 667 ram / HDD: 2.5" 250gb Fujitsu / DVD-RW samsung
OS: Windows XP Sp3
cool'n quiet: on
easysaver: on (maximum saving settings)
cpu / northbridge chipset undervolted (k10stat/Easytune6): minimum cpu voltage: 0.7 / minimum NB voltage: 0.98
[first step: psu: 500w generic (low efficiency)]
IDLE power consumption: 40w
MODERATE load (browser/office/Wmp on): 42-45w
HIGH load - prime95: 56w / Orthos: 59w
cpu temperature (moerate load): 25Âº C
noise: medium (psu fan + cpu fan on)
cpu fan: 1600-1800 rpm
[second step: swap psu to picopsu 120-wi + 120w-18.5v powerbrick]
IDLE power consumption: 30w [*if no program loaded, idle is 27-28w]
MODERATE load (browser/office/Wmp on): 32-35w
HIG load: prime95: 45w / Orthos: 45w
cpu temperature (moderate load): 26Âº C (after a while temp rise up to 29; the other sensors on the MoBo shows 32Âº, 39Âº and 47Âº C; after some hours cpu temp stay below 30Âº and mobo sensors all below 50Âº)
noise: inaudible (only cpu fan on)
cpu fan: 1600-2000 rpm *the stock amd fan has very low noise only if below 2000 rpm, then become a bit noisy.
1 - Athlon II x2 is a very efficient Cpu, working well and cool at low voltages.
2 - This kind of rig has an idle power consumption similar to an Atom330 but can perform a way better, finishing tasks (as video enconding, photo editing) in less time. So, probably, it will consumes less energy (I did not do yet more accurate measurements).
Doing web surfing or office tasks (word, excel) stay at an average 30-34w power consumption level.
update 8/04/2010: these are the lowest p-states I've tested:
at these voltages, there are no more gains in wattage, but the temperature stay very low, 18-24 ÂºC (rarely above 25), depending of room temp.