Hitting 50W peak on a dual-core desktop computer
The 50W no-compromise dual-core commodity desktop PC is now a reality!I have some great news for the green computing world. The 50W no-compromise dual-core commodity desktop PC is now a reality! It all started a few months back when I looked in to the possibility of building a main stream dual-core desktop computer that can drop under 50 watts idle but now I've answered that question beyond all expectations. Using a 220W Sparkle SPI220LE "80 Plus" efficient power supply, an Intel E2140 1.6 GHz dual-core CPU running at lower-than-spec 0.95 volts, and a Gigabyte G33M-DS2R motherboard, the system comes in just under 50 watts at *PEAK* CPU load generated by WPrime running 2 threads. If I could only find a smaller 100 watt 80 Plus power supply and hit the optimum 50% loading at peak power consumption, then it might be possible to get peak system loads down to around 45 watts.
At idle the system uses 41 watts which is actually one watt higher than my sub-$400 All-in-One LCD PC with an ECS 945GCT-M motherboard and an Intel E2180 2.0 GHz dual-core running at stock speeds and voltage. It turns out that this G33M-DS2R board with E2140 CPU running at stock speeds and voltage has an idle system power of 46 watts which is 6 watts higher than the ECS board with E2180. This was surprising to me since the new G33 chipset has a more energy efficient memory controller than the 945 chipset.
Possible explanations are the fact that the G33-based motherboard was running the memory at 400 MHz base clock (DDR2-800 memory) whereas the 945-based motherboard was running the memory at 200 MHz. One other factor is the fact that the Gigabyte G33M-DS2R Intel G33-based motherboard has a 6-port SATA ICH9R RAID controller along with a few more memory and PCI ports. This leads me to think that the combination 2x the memory clock and more components translates to an additional 6 watts of power consumption.
The following idle/peak power consumption charts are from data I collected.
* SPI SPI220LE 220W 80+ PSU ** No system fan which saves 1W power
Gigabyte with Intel CPU = G33M-DS2R motherboard Gigabyte AMD CPU = MA69GM-S2H motherboard MSI with AMD CPU = K9AGM2-FIH motherboard